tidb logical_plan_builder 源码
tidb logical_plan_builder 代码
文件路径：/planner/core/logical_plan_builder.go
// Copyright 2016 PingCAP, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package core
import (
"context"
"fmt"
"math"
"math/bits"
"sort"
"strconv"
"strings"
"time"
"unicode"
"github.com/pingcap/errors"
"github.com/pingcap/failpoint"
"github.com/pingcap/tidb/domain"
"github.com/pingcap/tidb/expression"
"github.com/pingcap/tidb/expression/aggregation"
"github.com/pingcap/tidb/infoschema"
"github.com/pingcap/tidb/kv"
"github.com/pingcap/tidb/metrics"
"github.com/pingcap/tidb/parser"
"github.com/pingcap/tidb/parser/ast"
"github.com/pingcap/tidb/parser/charset"
"github.com/pingcap/tidb/parser/format"
"github.com/pingcap/tidb/parser/model"
"github.com/pingcap/tidb/parser/mysql"
"github.com/pingcap/tidb/parser/opcode"
"github.com/pingcap/tidb/parser/terror"
fd "github.com/pingcap/tidb/planner/funcdep"
"github.com/pingcap/tidb/planner/property"
"github.com/pingcap/tidb/planner/util"
"github.com/pingcap/tidb/privilege"
"github.com/pingcap/tidb/sessionctx"
"github.com/pingcap/tidb/sessionctx/variable"
"github.com/pingcap/tidb/statistics"
"github.com/pingcap/tidb/statistics/handle"
"github.com/pingcap/tidb/table"
"github.com/pingcap/tidb/table/tables"
"github.com/pingcap/tidb/table/temptable"
"github.com/pingcap/tidb/types"
driver "github.com/pingcap/tidb/types/parser_driver"
util2 "github.com/pingcap/tidb/util"
"github.com/pingcap/tidb/util/chunk"
"github.com/pingcap/tidb/util/collate"
"github.com/pingcap/tidb/util/dbterror"
"github.com/pingcap/tidb/util/hack"
"github.com/pingcap/tidb/util/logutil"
"github.com/pingcap/tidb/util/mathutil"
"github.com/pingcap/tidb/util/plancodec"
"github.com/pingcap/tidb/util/set"
)
const (
// TiDBMergeJoin is hint enforce merge join.
TiDBMergeJoin = "tidb_smj"
// HintSMJ is hint enforce merge join.
HintSMJ = "merge_join"
// TiDBBroadCastJoin indicates applying broadcast join by force.
TiDBBroadCastJoin = "tidb_bcj"
// HintBCJ indicates applying broadcast join by force.
HintBCJ = "broadcast_join"
// HintStraightJoin causes TiDB to join tables in the order in which they appear in the FROM clause.
HintStraightJoin = "straight_join"
// HintLeading specifies the set of tables to be used as the prefix in the execution plan.
HintLeading = "leading"
// TiDBIndexNestedLoopJoin is hint enforce index nested loop join.
TiDBIndexNestedLoopJoin = "tidb_inlj"
// HintINLJ is hint enforce index nested loop join.
HintINLJ = "inl_join"
// HintINLHJ is hint enforce index nested loop hash join.
HintINLHJ = "inl_hash_join"
// HintINLMJ is hint enforce index nested loop merge join.
HintINLMJ = "inl_merge_join"
// TiDBHashJoin is hint enforce hash join.
TiDBHashJoin = "tidb_hj"
// HintHJ is hint enforce hash join.
HintHJ = "hash_join"
// HintHashJoinBuild is hint enforce hash join's build side
HintHashJoinBuild = "hash_join_build"
// HintHashJoinProbe is hint enforce hash join's probe side
HintHashJoinProbe = "hash_join_probe"
// HintHashAgg is hint enforce hash aggregation.
HintHashAgg = "hash_agg"
// HintStreamAgg is hint enforce stream aggregation.
HintStreamAgg = "stream_agg"
// HintUseIndex is hint enforce using some indexes.
HintUseIndex = "use_index"
// HintIgnoreIndex is hint enforce ignoring some indexes.
HintIgnoreIndex = "ignore_index"
// HintForceIndex make optimizer to use this index even if it thinks a table scan is more efficient.
HintForceIndex = "force_index"
// HintAggToCop is hint enforce pushing aggregation to coprocessor.
HintAggToCop = "agg_to_cop"
// HintReadFromStorage is hint enforce some tables read from specific type of storage.
HintReadFromStorage = "read_from_storage"
// HintTiFlash is a label represents the tiflash storage type.
HintTiFlash = "tiflash"
// HintTiKV is a label represents the tikv storage type.
HintTiKV = "tikv"
// HintIndexMerge is a hint to enforce using some indexes at the same time.
HintIndexMerge = "use_index_merge"
// HintTimeRange is a hint to specify the time range for metrics summary tables
HintTimeRange = "time_range"
// HintIgnorePlanCache is a hint to enforce ignoring plan cache
HintIgnorePlanCache = "ignore_plan_cache"
// HintLimitToCop is a hint enforce pushing limit or topn to coprocessor.
HintLimitToCop = "limit_to_cop"
//HintMerge is a hint which can switch turning inline for the CTE.
HintMerge = "merge"
// HintSemiJoinRewrite is a hint to force we rewrite the semi join operator as much as possible.
HintSemiJoinRewrite = "semi_join_rewrite"
)
const (
// ErrExprInSelect is in select fields for the error of ErrFieldNotInGroupBy
ErrExprInSelect = "SELECT list"
// ErrExprInOrderBy is in order by items for the error of ErrFieldNotInGroupBy
ErrExprInOrderBy = "ORDER BY"
)
// aggOrderByResolver is currently resolving expressions of order by clause
// in aggregate function GROUP_CONCAT.
type aggOrderByResolver struct {
ctx sessionctx.Context
err error
args []ast.ExprNode
exprDepth int // exprDepth is the depth of current expression in expression tree.
}
func (a *aggOrderByResolver) Enter(inNode ast.Node) (ast.Node, bool) {
a.exprDepth++
if n, ok := inNode.(*driver.ParamMarkerExpr); ok {
if a.exprDepth == 1 {
_, isNull, isExpectedType := getUintFromNode(a.ctx, n)
// For constant uint expression in top level, it should be treated as position expression.
if !isNull && isExpectedType {
return expression.ConstructPositionExpr(n), true
}
}
}
return inNode, false
}
func (a *aggOrderByResolver) Leave(inNode ast.Node) (ast.Node, bool) {
if v, ok := inNode.(*ast.PositionExpr); ok {
pos, isNull, err := expression.PosFromPositionExpr(a.ctx, v)
if err != nil {
a.err = err
}
if err != nil || isNull {
return inNode, false
}
if pos < 1 || pos > len(a.args) {
errPos := strconv.Itoa(pos)
if v.P != nil {
errPos = "?"
}
a.err = ErrUnknownColumn.FastGenByArgs(errPos, "order clause")
return inNode, false
}
ret := a.args[pos-1]
return ret, true
}
return inNode, true
}
func (b *PlanBuilder) buildAggregation(ctx context.Context, p LogicalPlan, aggFuncList []*ast.AggregateFuncExpr, gbyItems []expression.Expression,
correlatedAggMap map[*ast.AggregateFuncExpr]int) (LogicalPlan, map[int]int, error) {
b.optFlag |= flagBuildKeyInfo
b.optFlag |= flagPushDownAgg
// We may apply aggregation eliminate optimization.
// So we add the flagMaxMinEliminate to try to convert max/min to topn and flagPushDownTopN to handle the newly added topn operator.
b.optFlag |= flagMaxMinEliminate
b.optFlag |= flagPushDownTopN
// when we eliminate the max and min we may add `is not null` filter.
b.optFlag |= flagPredicatePushDown
b.optFlag |= flagEliminateAgg
b.optFlag |= flagEliminateProjection
if b.ctx.GetSessionVars().EnableSkewDistinctAgg {
b.optFlag |= flagSkewDistinctAgg
}
plan4Agg := LogicalAggregation{AggFuncs: make([]*aggregation.AggFuncDesc, 0, len(aggFuncList))}.Init(b.ctx, b.getSelectOffset())
if hint := b.TableHints(); hint != nil {
plan4Agg.aggHints = hint.aggHints
}
schema4Agg := expression.NewSchema(make([]*expression.Column, 0, len(aggFuncList)+p.Schema().Len())...)
names := make(types.NameSlice, 0, len(aggFuncList)+p.Schema().Len())
// aggIdxMap maps the old index to new index after applying common aggregation functions elimination.
aggIndexMap := make(map[int]int)
allAggsFirstRow := true
for i, aggFunc := range aggFuncList {
newArgList := make([]expression.Expression, 0, len(aggFunc.Args))
for _, arg := range aggFunc.Args {
newArg, np, err := b.rewrite(ctx, arg, p, nil, true)
if err != nil {
return nil, nil, err
}
p = np
newArgList = append(newArgList, newArg)
}
newFunc, err := aggregation.NewAggFuncDesc(b.ctx, aggFunc.F, newArgList, aggFunc.Distinct)
if err != nil {
return nil, nil, err
}
if newFunc.Name != ast.AggFuncFirstRow {
allAggsFirstRow = false
}
if aggFunc.Order != nil {
trueArgs := aggFunc.Args[:len(aggFunc.Args)-1] // the last argument is SEPARATOR, remote it.
resolver := &aggOrderByResolver{
ctx: b.ctx,
args: trueArgs,
}
for _, byItem := range aggFunc.Order.Items {
resolver.exprDepth = 0
resolver.err = nil
retExpr, _ := byItem.Expr.Accept(resolver)
if resolver.err != nil {
return nil, nil, errors.Trace(resolver.err)
}
newByItem, np, err := b.rewrite(ctx, retExpr.(ast.ExprNode), p, nil, true)
if err != nil {
return nil, nil, err
}
p = np
newFunc.OrderByItems = append(newFunc.OrderByItems, &util.ByItems{Expr: newByItem, Desc: byItem.Desc})
}
}
// combine identical aggregate functions
combined := false
for j := 0; j < i; j++ {
oldFunc := plan4Agg.AggFuncs[aggIndexMap[j]]
if oldFunc.Equal(b.ctx, newFunc) {
aggIndexMap[i] = aggIndexMap[j]
combined = true
if _, ok := correlatedAggMap[aggFunc]; ok {
if _, ok = b.correlatedAggMapper[aggFuncList[j]]; !ok {
b.correlatedAggMapper[aggFuncList[j]] = &expression.CorrelatedColumn{
Column: *schema4Agg.Columns[aggIndexMap[j]],
}
}
b.correlatedAggMapper[aggFunc] = b.correlatedAggMapper[aggFuncList[j]]
}
break
}
}
// create new columns for aggregate functions which show up first
if !combined {
position := len(plan4Agg.AggFuncs)
aggIndexMap[i] = position
plan4Agg.AggFuncs = append(plan4Agg.AggFuncs, newFunc)
column := expression.Column{
UniqueID: b.ctx.GetSessionVars().AllocPlanColumnID(),
RetType: newFunc.RetTp,
}
schema4Agg.Append(&column)
names = append(names, types.EmptyName)
if _, ok := correlatedAggMap[aggFunc]; ok {
b.correlatedAggMapper[aggFunc] = &expression.CorrelatedColumn{
Column: column,
}
}
}
}
for i, col := range p.Schema().Columns {
newFunc, err := aggregation.NewAggFuncDesc(b.ctx, ast.AggFuncFirstRow, []expression.Expression{col}, false)
if err != nil {
return nil, nil, err
}
plan4Agg.AggFuncs = append(plan4Agg.AggFuncs, newFunc)
newCol, _ := col.Clone().(*expression.Column)
newCol.RetType = newFunc.RetTp
schema4Agg.Append(newCol)
names = append(names, p.OutputNames()[i])
}
var (
join *LogicalJoin
isJoin bool
isSelectionJoin bool
)
join, isJoin = p.(*LogicalJoin)
selection, isSelection := p.(*LogicalSelection)
if isSelection {
join, isSelectionJoin = selection.children[0].(*LogicalJoin)
}
if (isJoin && join.fullSchema != nil) || (isSelectionJoin && join.fullSchema != nil) {
for i, col := range join.fullSchema.Columns {
if p.Schema().Contains(col) {
continue
}
newFunc, err := aggregation.NewAggFuncDesc(b.ctx, ast.AggFuncFirstRow, []expression.Expression{col}, false)
if err != nil {
return nil, nil, err
}
plan4Agg.AggFuncs = append(plan4Agg.AggFuncs, newFunc)
newCol, _ := col.Clone().(*expression.Column)
newCol.RetType = newFunc.RetTp
schema4Agg.Append(newCol)
names = append(names, join.fullNames[i])
}
}
hasGroupBy := len(gbyItems) > 0
for i, aggFunc := range plan4Agg.AggFuncs {
err := aggFunc.UpdateNotNullFlag4RetType(hasGroupBy, allAggsFirstRow)
if err != nil {
return nil, nil, err
}
schema4Agg.Columns[i].RetType = aggFunc.RetTp
}
plan4Agg.names = names
plan4Agg.SetChildren(p)
plan4Agg.GroupByItems = gbyItems
plan4Agg.SetSchema(schema4Agg)
return plan4Agg, aggIndexMap, nil
}
func (b *PlanBuilder) buildTableRefs(ctx context.Context, from *ast.TableRefsClause) (p LogicalPlan, err error) {
if from == nil {
p = b.buildTableDual()
return
}
defer func() {
// After build the resultSetNode, need to reset it so that it can be referenced by outer level.
for _, cte := range b.outerCTEs {
cte.recursiveRef = false
}
}()
return b.buildResultSetNode(ctx, from.TableRefs, false)
}
func (b *PlanBuilder) buildResultSetNode(ctx context.Context, node ast.ResultSetNode, IsCTE bool) (p LogicalPlan, err error) {
//If it is building the CTE queries, we will mark them.
b.isCTE = IsCTE
switch x := node.(type) {
case *ast.Join:
return b.buildJoin(ctx, x)
case *ast.TableSource:
var isTableName bool
switch v := x.Source.(type) {
case *ast.SelectStmt:
ci := b.prepareCTECheckForSubQuery()
defer resetCTECheckForSubQuery(ci)
p, err = b.buildSelect(ctx, v)
case *ast.SetOprStmt:
ci := b.prepareCTECheckForSubQuery()
defer resetCTECheckForSubQuery(ci)
p, err = b.buildSetOpr(ctx, v)
case *ast.TableName:
p, err = b.buildDataSource(ctx, v, &x.AsName)
isTableName = true
default:
err = ErrUnsupportedType.GenWithStackByArgs(v)
}
if err != nil {
return nil, err
}
for _, name := range p.OutputNames() {
if name.Hidden {
continue
}
if x.AsName.L != "" {
name.TblName = x.AsName
}
}
// `TableName` is not a select block, so we do not need to handle it.
if !isTableName && b.ctx.GetSessionVars().PlannerSelectBlockAsName != nil {
b.ctx.GetSessionVars().PlannerSelectBlockAsName[p.SelectBlockOffset()] = ast.HintTable{DBName: p.OutputNames()[0].DBName, TableName: p.OutputNames()[0].TblName}
}
// Duplicate column name in one table is not allowed.
// "select * from (select 1, 1) as a;" is duplicate
dupNames := make(map[string]struct{}, len(p.Schema().Columns))
for _, name := range p.OutputNames() {
colName := name.ColName.O
if _, ok := dupNames[colName]; ok {
return nil, ErrDupFieldName.GenWithStackByArgs(colName)
}
dupNames[colName] = struct{}{}
}
return p, nil
case *ast.SelectStmt:
return b.buildSelect(ctx, x)
case *ast.SetOprStmt:
return b.buildSetOpr(ctx, x)
default:
return nil, ErrUnsupportedType.GenWithStack("Unsupported ast.ResultSetNode(%T) for buildResultSetNode()", x)
}
}
// pushDownConstExpr checks if the condition is from filter condition, if true, push it down to both
// children of join, whatever the join type is; if false, push it down to inner child of outer join,
// and both children of non-outer-join.
func (p *LogicalJoin) pushDownConstExpr(expr expression.Expression, leftCond []expression.Expression,
rightCond []expression.Expression, filterCond bool) ([]expression.Expression, []expression.Expression) {
switch p.JoinType {
case LeftOuterJoin, LeftOuterSemiJoin, AntiLeftOuterSemiJoin:
if filterCond {
leftCond = append(leftCond, expr)
// Append the expr to right join condition instead of `rightCond`, to make it able to be
// pushed down to children of join.
p.RightConditions = append(p.RightConditions, expr)
} else {
rightCond = append(rightCond, expr)
}
case RightOuterJoin:
if filterCond {
rightCond = append(rightCond, expr)
p.LeftConditions = append(p.LeftConditions, expr)
} else {
leftCond = append(leftCond, expr)
}
case SemiJoin, InnerJoin:
leftCond = append(leftCond, expr)
rightCond = append(rightCond, expr)
case AntiSemiJoin:
if filterCond {
leftCond = append(leftCond, expr)
}
rightCond = append(rightCond, expr)
}
return leftCond, rightCond
}
func (p *LogicalJoin) extractOnCondition(conditions []expression.Expression, deriveLeft bool,
deriveRight bool) (eqCond []*expression.ScalarFunction, leftCond []expression.Expression,
rightCond []expression.Expression, otherCond []expression.Expression) {
return p.ExtractOnCondition(conditions, p.children[0].Schema(), p.children[1].Schema(), deriveLeft, deriveRight)
}
// ExtractOnCondition divide conditions in CNF of join node into 4 groups.
// These conditions can be where conditions, join conditions, or collection of both.
// If deriveLeft/deriveRight is set, we would try to derive more conditions for left/right plan.
func (p *LogicalJoin) ExtractOnCondition(
conditions []expression.Expression,
leftSchema *expression.Schema,
rightSchema *expression.Schema,
deriveLeft bool,
deriveRight bool) (eqCond []*expression.ScalarFunction, leftCond []expression.Expression,
rightCond []expression.Expression, otherCond []expression.Expression) {
for _, expr := range conditions {
// For queries like `select a in (select a from s where s.b = t.b) from t`,
// if subquery is empty caused by `s.b = t.b`, the result should always be
// false even if t.a is null or s.a is null. To make this join "empty aware",
// we should differentiate `t.a = s.a` from other column equal conditions, so
// we put it into OtherConditions instead of EqualConditions of join.
if expression.IsEQCondFromIn(expr) {
otherCond = append(otherCond, expr)
continue
}
binop, ok := expr.(*expression.ScalarFunction)
if ok && len(binop.GetArgs()) == 2 {
ctx := binop.GetCtx()
arg0, lOK := binop.GetArgs()[0].(*expression.Column)
arg1, rOK := binop.GetArgs()[1].(*expression.Column)
if lOK && rOK {
leftCol := leftSchema.RetrieveColumn(arg0)
rightCol := rightSchema.RetrieveColumn(arg1)
if leftCol == nil || rightCol == nil {
leftCol = leftSchema.RetrieveColumn(arg1)
rightCol = rightSchema.RetrieveColumn(arg0)
arg0, arg1 = arg1, arg0
}
if leftCol != nil && rightCol != nil {
if deriveLeft {
if isNullRejected(ctx, leftSchema, expr) && !mysql.HasNotNullFlag(leftCol.RetType.GetFlag()) {
notNullExpr := expression.BuildNotNullExpr(ctx, leftCol)
leftCond = append(leftCond, notNullExpr)
}
}
if deriveRight {
if isNullRejected(ctx, rightSchema, expr) && !mysql.HasNotNullFlag(rightCol.RetType.GetFlag()) {
notNullExpr := expression.BuildNotNullExpr(ctx, rightCol)
rightCond = append(rightCond, notNullExpr)
}
}
if binop.FuncName.L == ast.EQ {
cond := expression.NewFunctionInternal(ctx, ast.EQ, types.NewFieldType(mysql.TypeTiny), arg0, arg1)
eqCond = append(eqCond, cond.(*expression.ScalarFunction))
continue
}
}
}
}
columns := expression.ExtractColumns(expr)
// `columns` may be empty, if the condition is like `correlated_column op constant`, or `constant`,
// push this kind of constant condition down according to join type.
if len(columns) == 0 {
leftCond, rightCond = p.pushDownConstExpr(expr, leftCond, rightCond, deriveLeft || deriveRight)
continue
}
allFromLeft, allFromRight := true, true
for _, col := range columns {
if !leftSchema.Contains(col) {
allFromLeft = false
}
if !rightSchema.Contains(col) {
allFromRight = false
}
}
if allFromRight {
rightCond = append(rightCond, expr)
} else if allFromLeft {
leftCond = append(leftCond, expr)
} else {
// Relax expr to two supersets: leftRelaxedCond and rightRelaxedCond, the expression now is
// `expr AND leftRelaxedCond AND rightRelaxedCond`. Motivation is to push filters down to
// children as much as possible.
if deriveLeft {
leftRelaxedCond := expression.DeriveRelaxedFiltersFromDNF(expr, leftSchema)
if leftRelaxedCond != nil {
leftCond = append(leftCond, leftRelaxedCond)
}
}
if deriveRight {
rightRelaxedCond := expression.DeriveRelaxedFiltersFromDNF(expr, rightSchema)
if rightRelaxedCond != nil {
rightCond = append(rightCond, rightRelaxedCond)
}
}
otherCond = append(otherCond, expr)
}
}
return
}
// extractTableAlias returns table alias of the LogicalPlan's columns.
// It will return nil when there are multiple table alias, because the alias is only used to check if
// the logicalPlan match some optimizer hints, and hints are not expected to take effect in this case.
func extractTableAlias(p Plan, parentOffset int) *hintTableInfo {
if len(p.OutputNames()) > 0 && p.OutputNames()[0].TblName.L != "" {
firstName := p.OutputNames()[0]
for _, name := range p.OutputNames() {
if name.TblName.L != firstName.TblName.L || name.DBName.L != firstName.DBName.L {
return nil
}
}
blockOffset := p.SelectBlockOffset()
blockAsNames := p.SCtx().GetSessionVars().PlannerSelectBlockAsName
// For sub-queries like `(select * from t) t1`, t1 should belong to its surrounding select block.
if blockOffset != parentOffset && blockAsNames != nil && blockAsNames[blockOffset].TableName.L != "" {
blockOffset = parentOffset
}
dbName := firstName.DBName
if dbName.L == "" {
dbName = model.NewCIStr(p.SCtx().GetSessionVars().CurrentDB)
}
return &hintTableInfo{dbName: dbName, tblName: firstName.TblName, selectOffset: blockOffset}
}
return nil
}
func (p *LogicalJoin) setPreferredJoinTypeAndOrder(hintInfo *tableHintInfo) {
if hintInfo == nil {
return
}
lhsAlias := extractTableAlias(p.children[0], p.blockOffset)
rhsAlias := extractTableAlias(p.children[1], p.blockOffset)
if hintInfo.ifPreferMergeJoin(lhsAlias, rhsAlias) {
p.preferJoinType |= preferMergeJoin
}
if hintInfo.ifPreferBroadcastJoin(lhsAlias, rhsAlias) {
p.preferJoinType |= preferBCJoin
}
if hintInfo.ifPreferHashJoin(lhsAlias, rhsAlias) {
p.preferJoinType |= preferHashJoin
}
if hintInfo.ifPreferINLJ(lhsAlias) {
p.preferJoinType |= preferLeftAsINLJInner
}
if hintInfo.ifPreferINLJ(rhsAlias) {
p.preferJoinType |= preferRightAsINLJInner
}
if hintInfo.ifPreferINLHJ(lhsAlias) {
p.preferJoinType |= preferLeftAsINLHJInner
}
if hintInfo.ifPreferINLHJ(rhsAlias) {
p.preferJoinType |= preferRightAsINLHJInner
}
if hintInfo.ifPreferINLMJ(lhsAlias) {
p.preferJoinType |= preferLeftAsINLMJInner
}
if hintInfo.ifPreferINLMJ(rhsAlias) {
p.preferJoinType |= preferRightAsINLMJInner
}
if hintInfo.ifPreferHJBuild(lhsAlias) {
p.preferJoinType |= preferLeftAsHJBuild
}
if hintInfo.ifPreferHJBuild(rhsAlias) {
p.preferJoinType |= preferRightAsHJBuild
}
if hintInfo.ifPreferHJProbe(lhsAlias) {
p.preferJoinType |= preferLeftAsHJProbe
}
if hintInfo.ifPreferHJProbe(rhsAlias) {
p.preferJoinType |= preferRightAsHJProbe
}
if containDifferentJoinTypes(p.preferJoinType) {
errMsg := "Join hints are conflict, you can only specify one type of join"
warning := ErrInternal.GenWithStack(errMsg)
p.ctx.GetSessionVars().StmtCtx.AppendWarning(warning)
p.preferJoinType = 0
}
// set the join order
if hintInfo.leadingJoinOrder != nil {
p.preferJoinOrder = hintInfo.matchTableName([]*hintTableInfo{lhsAlias, rhsAlias}, hintInfo.leadingJoinOrder)
}
// set hintInfo for further usage if this hint info can be used.
if p.preferJoinType != 0 || p.preferJoinOrder {
p.hintInfo = hintInfo
}
}
func (ds *DataSource) setPreferredStoreType(hintInfo *tableHintInfo) {
if hintInfo == nil {
return
}
var alias *hintTableInfo
if len(ds.TableAsName.L) != 0 {
alias = &hintTableInfo{dbName: ds.DBName, tblName: *ds.TableAsName, selectOffset: ds.SelectBlockOffset()}
} else {
alias = &hintTableInfo{dbName: ds.DBName, tblName: ds.tableInfo.Name, selectOffset: ds.SelectBlockOffset()}
}
if hintTbl := hintInfo.ifPreferTiKV(alias); hintTbl != nil {
for _, path := range ds.possibleAccessPaths {
if path.StoreType == kv.TiKV {
ds.preferStoreType |= preferTiKV
ds.preferPartitions[preferTiKV] = hintTbl.partitions
break
}
}
if ds.preferStoreType&preferTiKV == 0 {
errMsg := fmt.Sprintf("No available path for table %s.%s with the store type %s of the hint /*+ read_from_storage */, "+
"please check the status of the table replica and variable value of tidb_isolation_read_engines(%v)",
ds.DBName.O, ds.table.Meta().Name.O, kv.TiKV.Name(), ds.ctx.GetSessionVars().GetIsolationReadEngines())
warning := ErrInternal.GenWithStack(errMsg)
ds.ctx.GetSessionVars().StmtCtx.AppendWarning(warning)
} else {
ds.ctx.GetSessionVars().RaiseWarningWhenMPPEnforced("MPP mode may be blocked because you have set a hint to read table `" + hintTbl.tblName.O + "` from TiKV.")
}
}
if hintTbl := hintInfo.ifPreferTiFlash(alias); hintTbl != nil {
// `ds.preferStoreType != 0`, which means there's a hint hit the both TiKV value and TiFlash value for table.
// We can't support read a table from two different storages, even partition table.
if ds.preferStoreType != 0 {
errMsg := fmt.Sprintf("Storage hints are conflict, you can only specify one storage type of table %s.%s",
alias.dbName.L, alias.tblName.L)
warning := ErrInternal.GenWithStack(errMsg)
ds.ctx.GetSessionVars().StmtCtx.AppendWarning(warning)
ds.preferStoreType = 0
return
}
for _, path := range ds.possibleAccessPaths {
if path.StoreType == kv.TiFlash {
ds.preferStoreType |= preferTiFlash
ds.preferPartitions[preferTiFlash] = hintTbl.partitions
break
}
}
if ds.preferStoreType&preferTiFlash == 0 {
errMsg := fmt.Sprintf("No available path for table %s.%s with the store type %s of the hint /*+ read_from_storage */, "+
"please check the status of the table replica and variable value of tidb_isolation_read_engines(%v)",
ds.DBName.O, ds.table.Meta().Name.O, kv.TiFlash.Name(), ds.ctx.GetSessionVars().GetIsolationReadEngines())
warning := ErrInternal.GenWithStack(errMsg)
ds.ctx.GetSessionVars().StmtCtx.AppendWarning(warning)
}
}
}
func resetNotNullFlag(schema *expression.Schema, start, end int) {
for i := start; i < end; i++ {
col := *schema.Columns[i]
newFieldType := *col.RetType
newFieldType.DelFlag(mysql.NotNullFlag)
col.RetType = &newFieldType
schema.Columns[i] = &col
}
}
func (b *PlanBuilder) buildJoin(ctx context.Context, joinNode *ast.Join) (LogicalPlan, error) {
// We will construct a "Join" node for some statements like "INSERT",
// "DELETE", "UPDATE", "REPLACE". For this scenario "joinNode.Right" is nil
// and we only build the left "ResultSetNode".
if joinNode.Right == nil {
return b.buildResultSetNode(ctx, joinNode.Left, false)
}
b.optFlag = b.optFlag | flagPredicatePushDown
// Add join reorder flag regardless of inner join or outer join.
b.optFlag = b.optFlag | flagJoinReOrder
leftPlan, err := b.buildResultSetNode(ctx, joinNode.Left, false)
if err != nil {
return nil, err
}
rightPlan, err := b.buildResultSetNode(ctx, joinNode.Right, false)
if err != nil {
return nil, err
}
// The recursive part in CTE must not be on the right side of a LEFT JOIN.
if lc, ok := rightPlan.(*LogicalCTETable); ok && joinNode.Tp == ast.LeftJoin {
return nil, ErrCTERecursiveForbiddenJoinOrder.GenWithStackByArgs(lc.name)
}
handleMap1 := b.handleHelper.popMap()
handleMap2 := b.handleHelper.popMap()
b.handleHelper.mergeAndPush(handleMap1, handleMap2)
joinPlan := LogicalJoin{StraightJoin: joinNode.StraightJoin || b.inStraightJoin}.Init(b.ctx, b.getSelectOffset())
joinPlan.SetChildren(leftPlan, rightPlan)
joinPlan.SetSchema(expression.MergeSchema(leftPlan.Schema(), rightPlan.Schema()))
joinPlan.names = make([]*types.FieldName, leftPlan.Schema().Len()+rightPlan.Schema().Len())
copy(joinPlan.names, leftPlan.OutputNames())
copy(joinPlan.names[leftPlan.Schema().Len():], rightPlan.OutputNames())
// Set join type.
switch joinNode.Tp {
case ast.LeftJoin:
// left outer join need to be checked elimination
b.optFlag = b.optFlag | flagEliminateOuterJoin
joinPlan.JoinType = LeftOuterJoin
resetNotNullFlag(joinPlan.schema, leftPlan.Schema().Len(), joinPlan.schema.Len())
case ast.RightJoin:
// right outer join need to be checked elimination
b.optFlag = b.optFlag | flagEliminateOuterJoin
joinPlan.JoinType = RightOuterJoin
resetNotNullFlag(joinPlan.schema, 0, leftPlan.Schema().Len())
default:
joinPlan.JoinType = InnerJoin
}
// Merge sub-plan's fullSchema into this join plan.
// Please read the comment of LogicalJoin.fullSchema for the details.
var (
lFullSchema, rFullSchema *expression.Schema
lFullNames, rFullNames types.NameSlice
)
if left, ok := leftPlan.(*LogicalJoin); ok && left.fullSchema != nil {
lFullSchema = left.fullSchema
lFullNames = left.fullNames
} else {
lFullSchema = leftPlan.Schema()
lFullNames = leftPlan.OutputNames()
}
if right, ok := rightPlan.(*LogicalJoin); ok && right.fullSchema != nil {
rFullSchema = right.fullSchema
rFullNames = right.fullNames
} else {
rFullSchema = rightPlan.Schema()
rFullNames = rightPlan.OutputNames()
}
if joinNode.Tp == ast.RightJoin {
// Make sure lFullSchema means outer full schema and rFullSchema means inner full schema.
lFullSchema, rFullSchema = rFullSchema, lFullSchema
lFullNames, rFullNames = rFullNames, lFullNames
}
joinPlan.fullSchema = expression.MergeSchema(lFullSchema, rFullSchema)
// Clear NotNull flag for the inner side schema if it's an outer join.
if joinNode.Tp == ast.LeftJoin || joinNode.Tp == ast.RightJoin {
resetNotNullFlag(joinPlan.fullSchema, lFullSchema.Len(), joinPlan.fullSchema.Len())
}
// Merge sub-plan's fullNames into this join plan, similar to the fullSchema logic above.
joinPlan.fullNames = make([]*types.FieldName, 0, len(lFullNames)+len(rFullNames))
for _, lName := range lFullNames {
name := *lName
joinPlan.fullNames = append(joinPlan.fullNames, &name)
}
for _, rName := range rFullNames {
name := *rName
joinPlan.fullNames = append(joinPlan.fullNames, &name)
}
// Set preferred join algorithm if some join hints is specified by user.
joinPlan.setPreferredJoinTypeAndOrder(b.TableHints())
// "NATURAL JOIN" doesn't have "ON" or "USING" conditions.
//
// The "NATURAL [LEFT] JOIN" of two tables is defined to be semantically
// equivalent to an "INNER JOIN" or a "LEFT JOIN" with a "USING" clause
// that names all columns that exist in both tables.
//
// See https://dev.mysql.com/doc/refman/5.7/en/join.html for more detail.
if joinNode.NaturalJoin {
err = b.buildNaturalJoin(joinPlan, leftPlan, rightPlan, joinNode)
if err != nil {
return nil, err
}
} else if joinNode.Using != nil {
err = b.buildUsingClause(joinPlan, leftPlan, rightPlan, joinNode)
if err != nil {
return nil, err
}
} else if joinNode.On != nil {
b.curClause = onClause
onExpr, newPlan, err := b.rewrite(ctx, joinNode.On.Expr, joinPlan, nil, false)
if err != nil {
return nil, err
}
if newPlan != joinPlan {
return nil, errors.New("ON condition doesn't support subqueries yet")
}
onCondition := expression.SplitCNFItems(onExpr)
// Keep these expressions as a LogicalSelection upon the inner join, in order to apply
// possible decorrelate optimizations. The ON clause is actually treated as a WHERE clause now.
if joinPlan.JoinType == InnerJoin {
sel := LogicalSelection{Conditions: onCondition}.Init(b.ctx, b.getSelectOffset())
sel.SetChildren(joinPlan)
return sel, nil
}
joinPlan.AttachOnConds(onCondition)
} else if joinPlan.JoinType == InnerJoin {
// If a inner join without "ON" or "USING" clause, it's a cartesian
// product over the join tables.
joinPlan.cartesianJoin = true
}
return joinPlan, nil
}
// buildUsingClause eliminate the redundant columns and ordering columns based
// on the "USING" clause.
//
// According to the standard SQL, columns are ordered in the following way:
// 1. coalesced common columns of "leftPlan" and "rightPlan", in the order they
// appears in "leftPlan".
// 2. the rest columns in "leftPlan", in the order they appears in "leftPlan".
// 3. the rest columns in "rightPlan", in the order they appears in "rightPlan".
func (b *PlanBuilder) buildUsingClause(p *LogicalJoin, leftPlan, rightPlan LogicalPlan, join *ast.Join) error {
filter := make(map[string]bool, len(join.Using))
for _, col := range join.Using {
filter[col.Name.L] = true
}
err := b.coalesceCommonColumns(p, leftPlan, rightPlan, join.Tp, filter)
if err != nil {
return err
}
// We do not need to coalesce columns for update and delete.
if b.inUpdateStmt || b.inDeleteStmt {
p.setSchemaAndNames(expression.MergeSchema(p.Children()[0].Schema(), p.Children()[1].Schema()),
append(p.Children()[0].OutputNames(), p.Children()[1].OutputNames()...))
}
return nil
}
// buildNaturalJoin builds natural join output schema. It finds out all the common columns
// then using the same mechanism as buildUsingClause to eliminate redundant columns and build join conditions.
// According to standard SQL, producing this display order:
//
// All the common columns
// Every column in the first (left) table that is not a common column
// Every column in the second (right) table that is not a common column
func (b *PlanBuilder) buildNaturalJoin(p *LogicalJoin, leftPlan, rightPlan LogicalPlan, join *ast.Join) error {
err := b.coalesceCommonColumns(p, leftPlan, rightPlan, join.Tp, nil)
if err != nil {
return err
}
// We do not need to coalesce columns for update and delete.
if b.inUpdateStmt || b.inDeleteStmt {
p.setSchemaAndNames(expression.MergeSchema(p.Children()[0].Schema(), p.Children()[1].Schema()),
append(p.Children()[0].OutputNames(), p.Children()[1].OutputNames()...))
}
return nil
}
// coalesceCommonColumns is used by buildUsingClause and buildNaturalJoin. The filter is used by buildUsingClause.
func (b *PlanBuilder) coalesceCommonColumns(p *LogicalJoin, leftPlan, rightPlan LogicalPlan, joinTp ast.JoinType, filter map[string]bool) error {
lsc := leftPlan.Schema().Clone()
rsc := rightPlan.Schema().Clone()
if joinTp == ast.LeftJoin {
resetNotNullFlag(rsc, 0, rsc.Len())
} else if joinTp == ast.RightJoin {
resetNotNullFlag(lsc, 0, lsc.Len())
}
lColumns, rColumns := lsc.Columns, rsc.Columns
lNames, rNames := leftPlan.OutputNames().Shallow(), rightPlan.OutputNames().Shallow()
if joinTp == ast.RightJoin {
leftPlan, rightPlan = rightPlan, leftPlan
lNames, rNames = rNames, lNames
lColumns, rColumns = rsc.Columns, lsc.Columns
}
// Check using clause with ambiguous columns.
if filter != nil {
checkAmbiguous := func(names types.NameSlice) error {
columnNameInFilter := set.StringSet{}
for _, name := range names {
if _, ok := filter[name.ColName.L]; !ok {
continue
}
if columnNameInFilter.Exist(name.ColName.L) {
return ErrAmbiguous.GenWithStackByArgs(name.ColName.L, "from clause")
}
columnNameInFilter.Insert(name.ColName.L)
}
return nil
}
err := checkAmbiguous(lNames)
if err != nil {
return err
}
err = checkAmbiguous(rNames)
if err != nil {
return err
}
}
// Find out all the common columns and put them ahead.
commonLen := 0
for i, lName := range lNames {
// Natural join should ignore _tidb_rowid
if lName.ColName.L == "_tidb_rowid" {
continue
}
for j := commonLen; j < len(rNames); j++ {
if lName.ColName.L != rNames[j].ColName.L {
continue
}
if len(filter) > 0 {
if !filter[lName.ColName.L] {
break
}
// Mark this column exist.
filter[lName.ColName.L] = false
}
col := lColumns[i]
copy(lColumns[commonLen+1:i+1], lColumns[commonLen:i])
lColumns[commonLen] = col
name := lNames[i]
copy(lNames[commonLen+1:i+1], lNames[commonLen:i])
lNames[commonLen] = name
col = rColumns[j]
copy(rColumns[commonLen+1:j+1], rColumns[commonLen:j])
rColumns[commonLen] = col
name = rNames[j]
copy(rNames[commonLen+1:j+1], rNames[commonLen:j])
rNames[commonLen] = name
commonLen++
break
}
}
if len(filter) > 0 && len(filter) != commonLen {
for col, notExist := range filter {
if notExist {
return ErrUnknownColumn.GenWithStackByArgs(col, "from clause")
}
}
}
schemaCols := make([]*expression.Column, len(lColumns)+len(rColumns)-commonLen)
copy(schemaCols[:len(lColumns)], lColumns)
copy(schemaCols[len(lColumns):], rColumns[commonLen:])
names := make(types.NameSlice, len(schemaCols))
copy(names, lNames)
copy(names[len(lNames):], rNames[commonLen:])
conds := make([]expression.Expression, 0, commonLen)
for i := 0; i < commonLen; i++ {
lc, rc := lsc.Columns[i], rsc.Columns[i]
cond, err := expression.NewFunction(b.ctx, ast.EQ, types.NewFieldType(mysql.TypeTiny), lc, rc)
if err != nil {
return err
}
conds = append(conds, cond)
if p.fullSchema != nil {
// since fullSchema is derived from left and right schema in upper layer, so rc/lc must be in fullSchema.
if joinTp == ast.RightJoin {
p.fullNames[p.fullSchema.ColumnIndex(lc)].Redundant = true
} else {
p.fullNames[p.fullSchema.ColumnIndex(rc)].Redundant = true
}
}
}
p.SetSchema(expression.NewSchema(schemaCols...))
p.names = names
p.OtherConditions = append(conds, p.OtherConditions...)
return nil
}
func (b *PlanBuilder) buildSelection(ctx context.Context, p LogicalPlan, where ast.ExprNode, aggMapper map[*ast.AggregateFuncExpr]int) (LogicalPlan, error) {
b.optFlag |= flagPredicatePushDown
if b.curClause != havingClause {
b.curClause = whereClause
}
conditions := splitWhere(where)
expressions := make([]expression.Expression, 0, len(conditions))
selection := LogicalSelection{}.Init(b.ctx, b.getSelectOffset())
for _, cond := range conditions {
expr, np, err := b.rewrite(ctx, cond, p, aggMapper, false)
if err != nil {
return nil, err
}
p = np
if expr == nil {
continue
}
expressions = append(expressions, expr)
}
cnfExpres := make([]expression.Expression, 0)
for _, expr := range expressions {
cnfItems := expression.SplitCNFItems(expr)
for _, item := range cnfItems {
if con, ok := item.(*expression.Constant); ok && con.DeferredExpr == nil && con.ParamMarker == nil {
ret, _, err := expression.EvalBool(b.ctx, expression.CNFExprs{con}, chunk.Row{})
if err != nil {
return nil, errors.Trace(err)
}
if ret {
continue
}
// If there is condition which is always false, return dual plan directly.
dual := LogicalTableDual{}.Init(b.ctx, b.getSelectOffset())
dual.names = p.OutputNames()
dual.SetSchema(p.Schema())
return dual, nil
}
cnfExpres = append(cnfExpres, item)
}
}
if len(cnfExpres) == 0 {
return p, nil
}
// check expr field types.
for i, expr := range cnfExpres {
if expr.GetType().EvalType() == types.ETString {
tp := &types.FieldType{}
tp.SetType(mysql.TypeDouble)
tp.SetFlag(expr.GetType().GetFlag())
tp.SetFlen(mysql.MaxRealWidth)
tp.SetDecimal(types.UnspecifiedLength)
types.SetBinChsClnFlag(tp)
cnfExpres[i] = expression.TryPushCastIntoControlFunctionForHybridType(b.ctx, expr, tp)
}
}
selection.Conditions = cnfExpres
selection.SetChildren(p)
return selection, nil
}
// buildProjectionFieldNameFromColumns builds the field name, table name and database name when field expression is a column reference.
func (b *PlanBuilder) buildProjectionFieldNameFromColumns(origField *ast.SelectField, colNameField *ast.ColumnNameExpr, name *types.FieldName) (colName, origColName, tblName, origTblName, dbName model.CIStr) {
origTblName, origColName, dbName = name.OrigTblName, name.OrigColName, name.DBName
if origField.AsName.L == "" {
colName = colNameField.Name.Name
} else {
colName = origField.AsName
}
if tblName.L == "" {
tblName = name.TblName
} else {
tblName = colNameField.Name.Table
}
return
}
// buildProjectionFieldNameFromExpressions builds the field name when field expression is a normal expression.
func (b *PlanBuilder) buildProjectionFieldNameFromExpressions(_ context.Context, field *ast.SelectField) (model.CIStr, error) {
if agg, ok := field.Expr.(*ast.AggregateFuncExpr); ok && agg.F == ast.AggFuncFirstRow {
// When the query is select t.a from t group by a; The Column Name should be a but not t.a;
return agg.Args[0].(*ast.ColumnNameExpr).Name.Name, nil
}
innerExpr := getInnerFromParenthesesAndUnaryPlus(field.Expr)
funcCall, isFuncCall := innerExpr.(*ast.FuncCallExpr)
// When used to produce a result set column, NAME_CONST() causes the column to have the given name.
// See https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_name-const for details
if isFuncCall && funcCall.FnName.L == ast.NameConst {
if v, err := evalAstExpr(b.ctx, funcCall.Args[0]); err == nil {
if s, err := v.ToString(); err == nil {
return model.NewCIStr(s), nil
}
}
return model.NewCIStr(""), ErrWrongArguments.GenWithStackByArgs("NAME_CONST")
}
valueExpr, isValueExpr := innerExpr.(*driver.ValueExpr)
// Non-literal: Output as inputed, except that comments need to be removed.
if !isValueExpr {
return model.NewCIStr(parser.SpecFieldPattern.ReplaceAllStringFunc(field.Text(), parser.TrimComment)), nil
}
// Literal: Need special processing
switch valueExpr.Kind() {
case types.KindString:
projName := valueExpr.GetString()
projOffset := valueExpr.GetProjectionOffset()
if projOffset >= 0 {
projName = projName[:projOffset]
}
// See #3686, #3994:
// For string literals, string content is used as column name. Non-graph initial characters are trimmed.
fieldName := strings.TrimLeftFunc(projName, func(r rune) bool {
return !unicode.IsOneOf(mysql.RangeGraph, r)
})
return model.NewCIStr(fieldName), nil
case types.KindNull:
// See #4053, #3685
return model.NewCIStr("NULL"), nil
case types.KindBinaryLiteral:
// Don't rewrite BIT literal or HEX literals
return model.NewCIStr(field.Text()), nil
case types.KindInt64:
// See #9683
// TRUE or FALSE can be a int64
if mysql.HasIsBooleanFlag(valueExpr.Type.GetFlag()) {
if i := valueExpr.GetValue().(int64); i == 0 {
return model.NewCIStr("FALSE"), nil
}
return model.NewCIStr("TRUE"), nil
}
fallthrough
default:
fieldName := field.Text()
fieldName = strings.TrimLeft(fieldName, "\t\n +(")
fieldName = strings.TrimRight(fieldName, "\t\n )")
return model.NewCIStr(fieldName), nil
}
}
// buildProjectionField builds the field object according to SelectField in projection.
func (b *PlanBuilder) buildProjectionField(ctx context.Context, p LogicalPlan, field *ast.SelectField, expr expression.Expression) (*expression.Column, *types.FieldName, error) {
var origTblName, tblName, origColName, colName, dbName model.CIStr
innerNode := getInnerFromParenthesesAndUnaryPlus(field.Expr)
col, isCol := expr.(*expression.Column)
// Correlated column won't affect the final output names. So we can put it in any of the three logic block.
// Don't put it into the first block just for simplifying the codes.
if colNameField, ok := innerNode.(*ast.ColumnNameExpr); ok && isCol {
// Field is a column reference.
idx := p.Schema().ColumnIndex(col)
var name *types.FieldName
// The column maybe the one from join's redundant part.
if idx == -1 {
name = findColFromNaturalUsingJoin(p, col)
} else {
name = p.OutputNames()[idx]
}
colName, origColName, tblName, origTblName, dbName = b.buildProjectionFieldNameFromColumns(field, colNameField, name)
} else if field.AsName.L != "" {
// Field has alias.
colName = field.AsName
} else {
// Other: field is an expression.
var err error
if colName, err = b.buildProjectionFieldNameFromExpressions(ctx, field); err != nil {
return nil, nil, err
}
}
name := &types.FieldName{
TblName: tblName,
OrigTblName: origTblName,
ColName: colName,
OrigColName: origColName,
DBName: dbName,
}
if isCol {
return col, name, nil
}
if expr == nil {
return nil, name, nil
}
// invalid unique id
correlatedColUniqueID := int64(0)
if cc, ok := expr.(*expression.CorrelatedColumn); ok {
correlatedColUniqueID = cc.UniqueID
}
// for expr projection, we should record the map relationship <hashcode, uniqueID> down.
newCol := &expression.Column{
UniqueID: b.ctx.GetSessionVars().AllocPlanColumnID(),
RetType: expr.GetType(),
CorrelatedColUniqueID: correlatedColUniqueID,
}
if b.ctx.GetSessionVars().OptimizerEnableNewOnlyFullGroupByCheck {
if b.ctx.GetSessionVars().MapHashCode2UniqueID4ExtendedCol == nil {
b.ctx.GetSessionVars().MapHashCode2UniqueID4ExtendedCol = make(map[string]int, 1)
}
b.ctx.GetSessionVars().MapHashCode2UniqueID4ExtendedCol[string(expr.HashCode(b.ctx.GetSessionVars().StmtCtx))] = int(newCol.UniqueID)
}
newCol.SetCoercibility(expr.Coercibility())
return newCol, name, nil
}
type userVarTypeProcessor struct {
ctx context.Context
plan LogicalPlan
builder *PlanBuilder
mapper map[*ast.AggregateFuncExpr]int
err error
}
func (p *userVarTypeProcessor) Enter(in ast.Node) (ast.Node, bool) {
v, ok := in.(*ast.VariableExpr)
if !ok {
return in, false
}
if v.IsSystem || v.Value == nil {
return in, true
}
_, p.plan, p.err = p.builder.rewrite(p.ctx, v, p.plan, p.mapper, true)
return in, true
}
func (p *userVarTypeProcessor) Leave(in ast.Node) (ast.Node, bool) {
return in, p.err == nil
}
func (b *PlanBuilder) preprocessUserVarTypes(ctx context.Context, p LogicalPlan, fields []*ast.SelectField, mapper map[*ast.AggregateFuncExpr]int) error {
aggMapper := make(map[*ast.AggregateFuncExpr]int)
for agg, i := range mapper {
aggMapper[agg] = i
}
processor := userVarTypeProcessor{
ctx: ctx,
plan: p,
builder: b,
mapper: aggMapper,
}
for _, field := range fields {
field.Expr.Accept(&processor)
if processor.err != nil {
return processor.err
}
}
return nil
}
// findColFromNaturalUsingJoin is used to recursively find the column from the
// underlying natural-using-join.
// e.g. For SQL like `select t2.a from t1 join t2 using(a) where t2.a > 0`, the
// plan will be `join->selection->projection`. The schema of the `selection`
// will be `[t1.a]`, thus we need to recursively retrieve the `t2.a` from the
// underlying join.
func findColFromNaturalUsingJoin(p LogicalPlan, col *expression.Column) (name *types.FieldName) {
switch x := p.(type) {
case *LogicalLimit, *LogicalSelection, *LogicalTopN, *LogicalSort, *LogicalMaxOneRow:
return findColFromNaturalUsingJoin(p.Children()[0], col)
case *LogicalJoin:
if x.fullSchema != nil {
idx := x.fullSchema.ColumnIndex(col)
return x.fullNames[idx]
}
}
return nil
}
// buildProjection returns a Projection plan and non-aux columns length.
func (b *PlanBuilder) buildProjection(ctx context.Context, p LogicalPlan, fields []*ast.SelectField, mapper map[*ast.AggregateFuncExpr]int,
windowMapper map[*ast.WindowFuncExpr]int, considerWindow bool, expandGenerateColumn bool) (LogicalPlan, []expression.Expression, int, error) {
err := b.preprocessUserVarTypes(ctx, p, fields, mapper)
if err != nil {
return nil, nil, 0, err
}
b.optFlag |= flagEliminateProjection
b.curClause = fieldList
proj := LogicalProjection{Exprs: make([]expression.Expression, 0, len(fields))}.Init(b.ctx, b.getSelectOffset())
schema := expression.NewSchema(make([]*expression.Column, 0, len(fields))...)
oldLen := 0
newNames := make([]*types.FieldName, 0, len(fields))
for i, field := range fields {
if !field.Auxiliary {
oldLen++
}
isWindowFuncField := ast.HasWindowFlag(field.Expr)
// Although window functions occurs in the select fields, but it has to be processed after having clause.
// So when we build the projection for select fields, we need to skip the window function.
// When `considerWindow` is false, we will only build fields for non-window functions, so we add fake placeholders.
// for window functions. These fake placeholders will be erased in column pruning.
// When `considerWindow` is true, all the non-window fields have been built, so we just use the schema columns.
if considerWindow && !isWindowFuncField {
col := p.Schema().Columns[i]
proj.Exprs = append(proj.Exprs, col)
schema.Append(col)
newNames = append(newNames, p.OutputNames()[i])
continue
} else if !considerWindow && isWindowFuncField {
expr := expression.NewZero()
proj.Exprs = append(proj.Exprs, expr)
col, name, err := b.buildProjectionField(ctx, p, field, expr)
if err != nil {
return nil, nil, 0, err
}
schema.Append(col)
newNames = append(newNames, name)
continue
}
newExpr, np, err := b.rewriteWithPreprocess(ctx, field.Expr, p, mapper, windowMapper, true, nil)
if err != nil {
return nil, nil, 0, err
}
// For window functions in the order by clause, we will append an field for it.
// We need rewrite the window mapper here so order by clause could find the added field.
if considerWindow && isWindowFuncField && field.Auxiliary {
if windowExpr, ok := field.Expr.(*ast.WindowFuncExpr); ok {
windowMapper[windowExpr] = i
}
}
p = np
proj.Exprs = append(proj.Exprs, newExpr)
col, name, err := b.buildProjectionField(ctx, p, field, newExpr)
if err != nil {
return nil, nil, 0, err
}
schema.Append(col)
newNames = append(newNames, name)
}
proj.SetSchema(schema)
proj.names = newNames
if expandGenerateColumn {
// Sometimes we need to add some fields to the projection so that we can use generate column substitute
// optimization. For example: select a+1 from t order by a+1, with a virtual generate column c as (a+1) and
// an index on c. We need to add c into the projection so that we can replace a+1 with c.
exprToColumn := make(ExprColumnMap)
collectGenerateColumn(p, exprToColumn)
for expr, col := range exprToColumn {
idx := p.Schema().ColumnIndex(col)
if idx == -1 {
continue
}
if proj.schema.Contains(col) {
continue
}
proj.schema.Columns = append(proj.schema.Columns, col)
proj.Exprs = append(proj.Exprs, expr)
proj.names = append(proj.names, p.OutputNames()[idx])
}
}
proj.SetChildren(p)
// delay the only-full-group-by-check in create view statement to later query.
if !b.isCreateView && b.ctx.GetSessionVars().OptimizerEnableNewOnlyFullGroupByCheck && b.ctx.GetSessionVars().SQLMode.HasOnlyFullGroupBy() {
fds := proj.ExtractFD()
// Projection -> Children -> ...
// Let the projection itself to evaluate the whole FD, which will build the connection
// 1: from select-expr to registered-expr
// 2: from base-column to select-expr
// After that
if fds.HasAggBuilt {
for offset, expr := range proj.Exprs[:len(fields)] {
// skip the auxiliary column in agg appended to select fields, which mainly comes from two kind of cases:
// 1: having agg(t.a), this will append t.a to the select fields, if it isn't here.
// 2: order by agg(t.a), this will append t.a to the select fields, if it isn't here.
if fields[offset].AuxiliaryColInAgg {
continue
}
item := fd.NewFastIntSet()
switch x := expr.(type) {
case *expression.Column:
item.Insert(int(x.UniqueID))
case *expression.ScalarFunction:
if expression.CheckFuncInExpr(x, ast.AnyValue) {
continue
}
scalarUniqueID, ok := fds.IsHashCodeRegistered(string(hack.String(x.HashCode(p.SCtx().GetSessionVars().StmtCtx))))
if !ok {
logutil.BgLogger().Warn("Error occurred while maintaining the functional dependency")
continue
}
item.Insert(scalarUniqueID)
default:
}
// Rule #1, if there are no group cols, the col in the order by shouldn't be limited.
if fds.GroupByCols.Only1Zero() && fields[offset].AuxiliaryColInOrderBy {
continue
}
// Rule #2, if select fields are constant, it's ok.
if item.SubsetOf(fds.ConstantCols()) {
continue
}
// Rule #3, if select fields are subset of group by items, it's ok.
if item.SubsetOf(fds.GroupByCols) {
continue
}
// Rule #4, if select fields are dependencies of Strict FD with determinants in group-by items, it's ok.
// lax FD couldn't be done here, eg: for unique key (b), index key NULL & NULL are different rows with
// uncertain other column values.
strictClosure := fds.ClosureOfStrict(fds.GroupByCols)
if item.SubsetOf(strictClosure) {
continue
}
// locate the base col that are not in (constant list / group by list / strict fd closure) for error show.
baseCols := expression.ExtractColumns(expr)
errShowCol := baseCols[0]
for _, col := range baseCols {
colSet := fd.NewFastIntSet(int(col.UniqueID))
if !colSet.SubsetOf(strictClosure) {
errShowCol = col
break
}
}
// better use the schema alias name firstly if any.
name := ""
for idx, schemaCol := range proj.Schema().Columns {
if schemaCol.UniqueID == errShowCol.UniqueID {
name = proj.names[idx].String()
break
}
}
if name == "" {
name = errShowCol.OrigName
}
// Only1Zero is to judge whether it's no-group-by-items case.
if !fds.GroupByCols.Only1Zero() {
return nil, nil, 0, ErrFieldNotInGroupBy.GenWithStackByArgs(offset+1, ErrExprInSelect, name)
}
return nil, nil, 0, ErrMixOfGroupFuncAndFields.GenWithStackByArgs(offset+1, name)
}
if fds.GroupByCols.Only1Zero() {
// maxOneRow is delayed from agg's ExtractFD logic since some details listed in it.
projectionUniqueIDs := fd.NewFastIntSet()
for _, expr := range proj.Exprs {
switch x := expr.(type) {
case *expression.Column:
projectionUniqueIDs.Insert(int(x.UniqueID))
case *expression.ScalarFunction:
scalarUniqueID, ok := fds.IsHashCodeRegistered(string(hack.String(x.HashCode(p.SCtx().GetSessionVars().StmtCtx))))
if !ok {
logutil.BgLogger().Warn("Error occurred while maintaining the functional dependency")
continue
}
projectionUniqueIDs.Insert(scalarUniqueID)
}
}
fds.MaxOneRow(projectionUniqueIDs)
}
// for select * from view (include agg), outer projection don't have to check select list with the inner group-by flag.
fds.HasAggBuilt = false
}
}
return proj, proj.Exprs, oldLen, nil
}
func (b *PlanBuilder) buildDistinct(child LogicalPlan, length int) (*LogicalAggregation, error) {
b.optFlag = b.optFlag | flagBuildKeyInfo
b.optFlag = b.optFlag | flagPushDownAgg
plan4Agg := LogicalAggregation{
AggFuncs: make([]*aggregation.AggFuncDesc, 0, child.Schema().Len()),
GroupByItems: expression.Column2Exprs(child.Schema().Clone().Columns[:length]),
}.Init(b.ctx, child.SelectBlockOffset())
if hint := b.TableHints(); hint != nil {
plan4Agg.aggHints = hint.aggHints
}
for _, col := range child.Schema().Columns {
aggDesc, err := aggregation.NewAggFuncDesc(b.ctx, ast.AggFuncFirstRow, []expression.Expression{col}, false)
if err != nil {
return nil, err
}
plan4Agg.AggFuncs = append(plan4Agg.AggFuncs, aggDesc)
}
plan4Agg.SetChildren(child)
plan4Agg.SetSchema(child.Schema().Clone())
plan4Agg.names = child.OutputNames()
// Distinct will be rewritten as first_row, we reset the type here since the return type
// of first_row is not always the same as the column arg of first_row.
for i, col := range plan4Agg.schema.Columns {
col.RetType = plan4Agg.AggFuncs[i].RetTp
}
return plan4Agg, nil
}
// unionJoinFieldType finds the type which can carry the given types in Union.
// Note that unionJoinFieldType doesn't handle charset and collation, caller need to handle it by itself.
func unionJoinFieldType(a, b *types.FieldType) *types.FieldType {
// We ignore the pure NULL type.
if a.GetType() == mysql.TypeNull {
return b
} else if b.GetType() == mysql.TypeNull {
return a
}
resultTp := types.NewFieldType(types.MergeFieldType(a.GetType(), b.GetType()))
// This logic will be intelligible when it is associated with the buildProjection4Union logic.
if resultTp.GetType() == mysql.TypeNewDecimal {
// The decimal result type will be unsigned only when all the decimals to be united are unsigned.
resultTp.AndFlag(b.GetFlag() & mysql.UnsignedFlag)
} else {
// Non-decimal results will be unsigned when a,b both unsigned.
// ref1: https://dev.mysql.com/doc/refman/5.7/en/union.html#union-result-set
// ref2: https://github.com/pingcap/tidb/issues/24953
resultTp.AddFlag((a.GetFlag() & mysql.UnsignedFlag) & (b.GetFlag() & mysql.UnsignedFlag))
}
resultTp.SetDecimalUnderLimit(mathutil.Max(a.GetDecimal(), b.GetDecimal()))
// `flen - decimal` is the fraction before '.'
resultTp.SetFlenUnderLimit(mathutil.Max(a.GetFlen()-a.GetDecimal(), b.GetFlen()-b.GetDecimal()) + resultTp.GetDecimal())
types.TryToFixFlenOfDatetime(resultTp)
if resultTp.EvalType() != types.ETInt && (a.EvalType() == types.ETInt || b.EvalType() == types.ETInt) && resultTp.GetFlen() < mysql.MaxIntWidth {
resultTp.SetFlen(mysql.MaxIntWidth)
}
expression.SetBinFlagOrBinStr(b, resultTp)
return resultTp
}
// Set the flen of the union column using the max flen in children.
func (b *PlanBuilder) setUnionFlen(resultTp *types.FieldType, cols []expression.Expression) {
isBinary := resultTp.GetCharset() == charset.CharsetBin
for i := 0; i < len(cols); i++ {
childTp := cols[i].GetType()
childTpCharLen := 1
if isBinary {
childTpCharLen = charset.CharacterSetInfos[childTp.GetCharset()].Maxlen
}
resultTp.SetFlen(mathutil.Max(resultTp.GetFlen(), childTpCharLen*childTp.GetFlen()))
}
}
func (b *PlanBuilder) buildProjection4Union(_ context.Context, u *LogicalUnionAll) error {
unionCols := make([]*expression.Column, 0, u.children[0].Schema().Len())
names := make([]*types.FieldName, 0, u.children[0].Schema().Len())
// Infer union result types by its children's schema.
for i, col := range u.children[0].Schema().Columns {
tmpExprs := make([]expression.Expression, 0, len(u.Children()))
tmpExprs = append(tmpExprs, col)
resultTp := col.RetType
for j := 1; j < len(u.children); j++ {
tmpExprs = append(tmpExprs, u.children[j].Schema().Columns[i])
childTp := u.children[j].Schema().Columns[i].RetType
resultTp = unionJoinFieldType(resultTp, childTp)
}
collation, err := expression.CheckAndDeriveCollationFromExprs(b.ctx, "UNION", resultTp.EvalType(), tmpExprs...)
if err != nil || collation.Coer == expression.CoercibilityNone {
return collate.ErrIllegalMixCollation.GenWithStackByArgs("UNION")
}
resultTp.SetCharset(collation.Charset)
resultTp.SetCollate(collation.Collation)
b.setUnionFlen(resultTp, tmpExprs)
names = append(names, &types.FieldName{ColName: u.children[0].OutputNames()[i].ColName})
unionCols = append(unionCols, &expression.Column{
RetType: resultTp,
UniqueID: b.ctx.GetSessionVars().AllocPlanColumnID(),
})
}
u.schema = expression.NewSchema(unionCols...)
u.names = names
// Process each child and add a projection above original child.
// So the schema of `UnionAll` can be the same with its children's.
for childID, child := range u.children {
exprs := make([]expression.Expression, len(child.Schema().Columns))
for i, srcCol := range child.Schema().Columns {
dstType := unionCols[i].RetType
srcType := srcCol.RetType
if !srcType.Equal(dstType) {
exprs[i] = expression.BuildCastFunction4Union(b.ctx, srcCol, dstType)
} else {
exprs[i] = srcCol
}
}
b.optFlag |= flagEliminateProjection
proj := LogicalProjection{Exprs: exprs, AvoidColumnEvaluator: true}.Init(b.ctx, b.getSelectOffset())
proj.SetSchema(u.schema.Clone())
// reset the schema type to make the "not null" flag right.
for i, expr := range exprs {
proj.schema.Columns[i].RetType = expr.GetType()
}
proj.SetChildren(child)
u.children[childID] = proj
}
return nil
}
func (b *PlanBuilder) buildSetOpr(ctx context.Context, setOpr *ast.SetOprStmt) (LogicalPlan, error) {
if setOpr.With != nil {
l := len(b.outerCTEs)
defer func() {
b.outerCTEs = b.outerCTEs[:l]
}()
err := b.buildWith(ctx, setOpr.With)
if err != nil {
return nil, err
}
}
// Because INTERSECT has higher precedence than UNION and EXCEPT. We build it first.
selectPlans := make([]LogicalPlan, 0, len(setOpr.SelectList.Selects))
afterSetOprs := make([]*ast.SetOprType, 0, len(setOpr.SelectList.Selects))
selects := setOpr.SelectList.Selects
for i := 0; i < len(selects); i++ {
intersects := []ast.Node{selects[i]}
for i+1 < len(selects) {
breakIteration := false
switch x := selects[i+1].(type) {
case *ast.SelectStmt:
if *x.AfterSetOperator != ast.Intersect && *x.AfterSetOperator != ast.IntersectAll {
breakIteration = true
}
case *ast.SetOprSelectList:
if *x.AfterSetOperator != ast.Intersect && *x.AfterSetOperator != ast.IntersectAll {
breakIteration = true
}
}
if breakIteration {
break
}
intersects = append(intersects, selects[i+1])
i++
}
selectPlan, afterSetOpr, err := b.buildIntersect(ctx, intersects)
if err != nil {
return nil, err
}
selectPlans = append(selectPlans, selectPlan)
afterSetOprs = append(afterSetOprs, afterSetOpr)
}
setOprPlan, err := b.buildExcept(ctx, selectPlans, afterSetOprs)
if err != nil {
return nil, err
}
oldLen := setOprPlan.Schema().Len()
for i := 0; i < len(setOpr.SelectList.Selects); i++ {
b.handleHelper.popMap()
}
b.handleHelper.pushMap(nil)
if setOpr.OrderBy != nil {
setOprPlan, err = b.buildSort(ctx, setOprPlan, setOpr.OrderBy.Items, nil, nil)
if err != nil {
return nil, err
}
}
if setOpr.Limit != nil {
setOprPlan, err = b.buildLimit(setOprPlan, setOpr.Limit)
if err != nil {
return nil, err
}
}
// Fix issue #8189 (https://github.com/pingcap/tidb/issues/8189).
// If there are extra expressions generated from `ORDER BY` clause, generate a `Projection` to remove them.
if oldLen != setOprPlan.Schema().Len() {
proj := LogicalProjection{Exprs: expression.Column2Exprs(setOprPlan.Schema().Columns[:oldLen])}.Init(b.ctx, b.getSelectOffset())
proj.SetChildren(setOprPlan)
schema := expression.NewSchema(setOprPlan.Schema().Clone().Columns[:oldLen]...)
for _, col := range schema.Columns {
col.UniqueID = b.ctx.GetSessionVars().AllocPlanColumnID()
}
proj.names = setOprPlan.OutputNames()[:oldLen]
proj.SetSchema(schema)
return proj, nil
}
return setOprPlan, nil
}
func (b *PlanBuilder) buildSemiJoinForSetOperator(
leftOriginPlan LogicalPlan,
rightPlan LogicalPlan,
joinType JoinType) (leftPlan LogicalPlan, err error) {
leftPlan, err = b.buildDistinct(leftOriginPlan, leftOriginPlan.Schema().Len())
if err != nil {
return nil, err
}
joinPlan := LogicalJoin{JoinType: joinType}.Init(b.ctx, b.getSelectOffset())
joinPlan.SetChildren(leftPlan, rightPlan)
joinPlan.SetSchema(leftPlan.Schema())
joinPlan.names = make([]*types.FieldName, leftPlan.Schema().Len())
copy(joinPlan.names, leftPlan.OutputNames())
for j := 0; j < len(rightPlan.Schema().Columns); j++ {
leftCol, rightCol := leftPlan.Schema().Columns[j], rightPlan.Schema().Columns[j]
eqCond, err := expression.NewFunction(b.ctx, ast.NullEQ, types.NewFieldType(mysql.TypeTiny), leftCol, rightCol)
if err != nil {
return nil, err
}
if leftCol.RetType.GetType() != rightCol.RetType.GetType() {
joinPlan.OtherConditions = append(joinPlan.OtherConditions, eqCond)
} else {
joinPlan.EqualConditions = append(joinPlan.EqualConditions, eqCond.(*expression.ScalarFunction))
}
}
return joinPlan, nil
}
// buildIntersect build the set operator for 'intersect'. It is called before buildExcept and buildUnion because of its
// higher precedence.
func (b *PlanBuilder) buildIntersect(ctx context.Context, selects []ast.Node) (LogicalPlan, *ast.SetOprType, error) {
var leftPlan LogicalPlan
var err error
var afterSetOperator *ast.SetOprType
switch x := selects[0].(type) {
case *ast.SelectStmt:
afterSetOperator = x.AfterSetOperator
leftPlan, err = b.buildSelect(ctx, x)
case *ast.SetOprSelectList:
afterSetOperator = x.AfterSetOperator
leftPlan, err = b.buildSetOpr(ctx, &ast.SetOprStmt{SelectList: x})
}
if err != nil {
return nil, nil, err
}
if len(selects) == 1 {
return leftPlan, afterSetOperator, nil
}
columnNums := leftPlan.Schema().Len()
for i := 1; i < len(selects); i++ {
var rightPlan LogicalPlan
switch x := selects[i].(type) {
case *ast.SelectStmt:
if *x.AfterSetOperator == ast.IntersectAll {
// TODO: support intersect all
return nil, nil, errors.Errorf("TiDB do not support intersect all")
}
rightPlan, err = b.buildSelect(ctx, x)
case *ast.SetOprSelectList:
if *x.AfterSetOperator == ast.IntersectAll {
// TODO: support intersect all
return nil, nil, errors.Errorf("TiDB do not support intersect all")
}
rightPlan, err = b.buildSetOpr(ctx, &ast.SetOprStmt{SelectList: x})
}
if err != nil {
return nil, nil, err
}
if rightPlan.Schema().Len() != columnNums {
return nil, nil, ErrWrongNumberOfColumnsInSelect.GenWithStackByArgs()
}
leftPlan, err = b.buildSemiJoinForSetOperator(leftPlan, rightPlan, SemiJoin)
if err != nil {
return nil, nil, err
}
}
return leftPlan, afterSetOperator, nil
}
// buildExcept build the set operators for 'except', and in this function, it calls buildUnion at the same time. Because
// Union and except has the same precedence.
func (b *PlanBuilder) buildExcept(ctx context.Context, selects []LogicalPlan, afterSetOpts []*ast.SetOprType) (LogicalPlan, error) {
unionPlans := []LogicalPlan{selects[0]}
tmpAfterSetOpts := []*ast.SetOprType{nil}
columnNums := selects[0].Schema().Len()
for i := 1; i < len(selects); i++ {
rightPlan := selects[i]
if rightPlan.Schema().Len() != columnNums {
return nil, ErrWrongNumberOfColumnsInSelect.GenWithStackByArgs()
}
if *afterSetOpts[i] == ast.Except {
leftPlan, err := b.buildUnion(ctx, unionPlans, tmpAfterSetOpts)
if err != nil {
return nil, err
}
leftPlan, err = b.buildSemiJoinForSetOperator(leftPlan, rightPlan, AntiSemiJoin)
if err != nil {
return nil, err
}
unionPlans = []LogicalPlan{leftPlan}
tmpAfterSetOpts = []*ast.SetOprType{nil}
} else if *afterSetOpts[i] == ast.ExceptAll {
// TODO: support except all.
return nil, errors.Errorf("TiDB do not support except all")
} else {
unionPlans = append(unionPlans, rightPlan)
tmpAfterSetOpts = append(tmpAfterSetOpts, afterSetOpts[i])
}
}
return b.buildUnion(ctx, unionPlans, tmpAfterSetOpts)
}
func (b *PlanBuilder) buildUnion(ctx context.Context, selects []LogicalPlan, afterSetOpts []*ast.SetOprType) (LogicalPlan, error) {
if len(selects) == 1 {
return selects[0], nil
}
distinctSelectPlans, allSelectPlans, err := b.divideUnionSelectPlans(ctx, selects, afterSetOpts)
if err != nil {
return nil, err
}
unionDistinctPlan, err := b.buildUnionAll(ctx, distinctSelectPlans)
if err != nil {
return nil, err
}
if unionDistinctPlan != nil {
unionDistinctPlan, err = b.buildDistinct(unionDistinctPlan, unionDistinctPlan.Schema().Len())
if err != nil {
return nil, err
}
if len(allSelectPlans) > 0 {
// Can't change the statements order in order to get the correct column info.
allSelectPlans = append([]LogicalPlan{unionDistinctPlan}, allSelectPlans...)
}
}
unionAllPlan, err := b.buildUnionAll(ctx, allSelectPlans)
if err != nil {
return nil, err
}
unionPlan := unionDistinctPlan
if unionAllPlan != nil {
unionPlan = unionAllPlan
}
return unionPlan, nil
}
// divideUnionSelectPlans resolves union's select stmts to logical plans.
// and divide result plans into "union-distinct" and "union-all" parts.
// divide rule ref:
//
// https://dev.mysql.com/doc/refman/5.7/en/union.html
//
// "Mixed UNION types are treated such that a DISTINCT union overrides any ALL union to its left."
func (b *PlanBuilder) divideUnionSelectPlans(_ context.Context, selects []LogicalPlan, setOprTypes []*ast.SetOprType) (distinctSelects []LogicalPlan, allSelects []LogicalPlan, err error) {
firstUnionAllIdx := 0
columnNums := selects[0].Schema().Len()
for i := len(selects) - 1; i > 0; i-- {
if firstUnionAllIdx == 0 && *setOprTypes[i] != ast.UnionAll {
firstUnionAllIdx = i + 1
}
if selects[i].Schema().Len() != columnNums {
return nil, nil, ErrWrongNumberOfColumnsInSelect.GenWithStackByArgs()
}
}
return selects[:firstUnionAllIdx], selects[firstUnionAllIdx:], nil
}
func (b *PlanBuilder) buildUnionAll(ctx context.Context, subPlan []LogicalPlan) (LogicalPlan, error) {
if len(subPlan) == 0 {
return nil, nil
}
u := LogicalUnionAll{}.Init(b.ctx, b.getSelectOffset())
u.children = subPlan
err := b.buildProjection4Union(ctx, u)
return u, err
}
// itemTransformer transforms ParamMarkerExpr to PositionExpr in the context of ByItem
type itemTransformer struct {
}
func (t *itemTransformer) Enter(inNode ast.Node) (ast.Node, bool) {
if n, ok := inNode.(*driver.ParamMarkerExpr); ok {
newNode := expression.ConstructPositionExpr(n)
return newNode, true
}
return inNode, false
}
func (t *itemTransformer) Leave(inNode ast.Node) (ast.Node, bool) {
return inNode, false
}
func (b *PlanBuilder) buildSort(ctx context.Context, p LogicalPlan, byItems []*ast.ByItem, aggMapper map[*ast.AggregateFuncExpr]int, windowMapper map[*ast.WindowFuncExpr]int) (*LogicalSort, error) {
return b.buildSortWithCheck(ctx, p, byItems, aggMapper, windowMapper, nil, 0, false)
}
func (b *PlanBuilder) buildSortWithCheck(ctx context.Context, p LogicalPlan, byItems []*ast.ByItem, aggMapper map[*ast.AggregateFuncExpr]int, windowMapper map[*ast.WindowFuncExpr]int,
projExprs []expression.Expression, oldLen int, hasDistinct bool) (*LogicalSort, error) {
if _, isUnion := p.(*LogicalUnionAll); isUnion {
b.curClause = globalOrderByClause
} else {
b.curClause = orderByClause
}
sort := LogicalSort{}.Init(b.ctx, b.getSelectOffset())
exprs := make([]*util.ByItems, 0, len(byItems))
transformer := &itemTransformer{}
for i, item := range byItems {
newExpr, _ := item.Expr.Accept(transformer)
item.Expr = newExpr.(ast.ExprNode)
it, np, err := b.rewriteWithPreprocess(ctx, item.Expr, p, aggMapper, windowMapper, true, nil)
if err != nil {
return nil, err
}
// check whether ORDER BY items show up in SELECT DISTINCT fields, see #12442
if hasDistinct && projExprs != nil {
err = b.checkOrderByInDistinct(item, i, it, p, projExprs, oldLen)
if err != nil {
return nil, err
}
}
p = np
exprs = append(exprs, &util.ByItems{Expr: it, Desc: item.Desc})
}
sort.ByItems = exprs
sort.SetChildren(p)
return sort, nil
}
// checkOrderByInDistinct checks whether ORDER BY has conflicts with DISTINCT, see #12442
func (b *PlanBuilder) checkOrderByInDistinct(byItem *ast.ByItem, idx int, expr expression.Expression, p LogicalPlan, originalExprs []expression.Expression, length int) error {
// Check if expressions in ORDER BY whole match some fields in DISTINCT.
// e.g.
// select distinct count(a) from t group by b order by count(a); ✔
// select distinct a+1 from t order by a+1; ✔
// select distinct a+1 from t order by a+2; ✗
for j := 0; j < length; j++ {
// both check original expression & as name
if expr.Equal(b.ctx, originalExprs[j]) || expr.Equal(b.ctx, p.Schema().Columns[j]) {
return nil
}
}
// Check if referenced columns of expressions in ORDER BY whole match some fields in DISTINCT,
// both original expression and alias can be referenced.
// e.g.
// select distinct a from t order by sin(a); ✔
// select distinct a, b from t order by a+b; ✔
// select distinct count(a), sum(a) from t group by b order by sum(a); ✔
cols := expression.ExtractColumns(expr)
CheckReferenced:
for _, col := range cols {
for j := 0; j < length; j++ {
if col.Equal(b.ctx, originalExprs[j]) || col.Equal(b.ctx, p.Schema().Columns[j]) {
continue CheckReferenced
}
}
// Failed cases
// e.g.
// select distinct sin(a) from t order by a; ✗
// select distinct a from t order by a+b; ✗
if _, ok := byItem.Expr.(*ast.AggregateFuncExpr); ok {
return ErrAggregateInOrderNotSelect.GenWithStackByArgs(idx+1, "DISTINCT")
}
// select distinct count(a) from t group by b order by sum(a); ✗
return ErrFieldInOrderNotSelect.GenWithStackByArgs(idx+1, col.OrigName, "DISTINCT")
}
return nil
}
// getUintFromNode gets uint64 value from ast.Node.
// For ordinary statement, node should be uint64 constant value.
// For prepared statement, node is string. We should convert it to uint64.
func getUintFromNode(ctx sessionctx.Context, n ast.Node) (uVal uint64, isNull bool, isExpectedType bool) {
var val interface{}
switch v := n.(type) {
case *driver.ValueExpr:
val = v.GetValue()
case *driver.ParamMarkerExpr:
if !v.InExecute {
return 0, false, true
}
param, err := expression.ParamMarkerExpression(ctx, v, false)
if err != nil {
return 0, false, false
}
str, isNull, err := expression.GetStringFromConstant(ctx, param)
if err != nil {
return 0, false, false
}
if isNull {
return 0, true, true
}
val = str
default:
return 0, false, false
}
switch v := val.(type) {
case uint64:
return v, false, true
case int64:
if v >= 0 {
return uint64(v), false, true
}
case string:
sc := ctx.GetSessionVars().StmtCtx
uVal, err := types.StrToUint(sc, v, false)
if err != nil {
return 0, false, false
}
return uVal, false, true
}
return 0, false, false
}
func extractLimitCountOffset(ctx sessionctx.Context, limit *ast.Limit) (count uint64,
offset uint64, err error) {
var isExpectedType bool
if limit.Count != nil {
count, _, isExpectedType = getUintFromNode(ctx, limit.Count)
if !isExpectedType {
return 0, 0, ErrWrongArguments.GenWithStackByArgs("LIMIT")
}
}
if limit.Offset != nil {
offset, _, isExpectedType = getUintFromNode(ctx, limit.Offset)
if !isExpectedType {
return 0, 0, ErrWrongArguments.GenWithStackByArgs("LIMIT")
}
}
return count, offset, nil
}
func (b *PlanBuilder) buildLimit(src LogicalPlan, limit *ast.Limit) (LogicalPlan, error) {
b.optFlag = b.optFlag | flagPushDownTopN
var (
offset, count uint64
err error
)
if count, offset, err = extractLimitCountOffset(b.ctx, limit); err != nil {
return nil, err
}
if count > math.MaxUint64-offset {
count = math.MaxUint64 - offset
}
if offset+count == 0 {
tableDual := LogicalTableDual{RowCount: 0}.Init(b.ctx, b.getSelectOffset())
tableDual.schema = src.Schema()
tableDual.names = src.OutputNames()
return tableDual, nil
}
li := LogicalLimit{
Offset: offset,
Count: count,
}.Init(b.ctx, b.getSelectOffset())
if hint := b.TableHints(); hint != nil {
li.limitHints = hint.limitHints
}
li.SetChildren(src)
return li, nil
}
// colMatch means that if a match b, e.g. t.a can match test.t.a but test.t.a can't match t.a.
// Because column a want column from database test exactly.
func colMatch(a *ast.ColumnName, b *ast.ColumnName) bool {
if a.Schema.L == "" || a.Schema.L == b.Schema.L {
if a.Table.L == "" || a.Table.L == b.Table.L {
return a.Name.L == b.Name.L
}
}
return false
}
func matchField(f *ast.SelectField, col *ast.ColumnNameExpr, ignoreAsName bool) bool {
// if col specify a table name, resolve from table source directly.
if col.Name.Table.L == "" {
if f.AsName.L == "" || ignoreAsName {
if curCol, isCol := f.Expr.(*ast.ColumnNameExpr); isCol {
return curCol.Name.Name.L == col.Name.Name.L
} else if _, isFunc := f.Expr.(*ast.FuncCallExpr); isFunc {
// Fix issue 7331
// If there are some function calls in SelectField, we check if
// ColumnNameExpr in GroupByClause matches one of these function calls.
// Example: select concat(k1,k2) from t group by `concat(k1,k2)`,
// `concat(k1,k2)` matches with function call concat(k1, k2).
return strings.ToLower(f.Text()) == col.Name.Name.L
}
// a expression without as name can't be matched.
return false
}
return f.AsName.L == col.Name.Name.L
}
return false
}
func resolveFromSelectFields(v *ast.ColumnNameExpr, fields []*ast.SelectField, ignoreAsName bool) (index int, err error) {
var matchedExpr ast.ExprNode
index = -1
for i, field := range fields {
if field.Auxiliary {
continue
}
if matchField(field, v, ignoreAsName) {
curCol, isCol := field.Expr.(*ast.ColumnNameExpr)
if !isCol {
return i, nil
}
if matchedExpr == nil {
matchedExpr = curCol
index = i
} else if !colMatch(matchedExpr.(*ast.ColumnNameExpr).Name, curCol.Name) &&
!colMatch(curCol.Name, matchedExpr.(*ast.ColumnNameExpr).Name) {
return -1, ErrAmbiguous.GenWithStackByArgs(curCol.Name.Name.L, clauseMsg[fieldList])
}
}
}
return
}
// havingWindowAndOrderbyExprResolver visits Expr tree.
// It converts ColunmNameExpr to AggregateFuncExpr and collects AggregateFuncExpr.
type havingWindowAndOrderbyExprResolver struct {
inAggFunc bool
inWindowFunc bool
inWindowSpec bool
inExpr bool
err error
p LogicalPlan
selectFields []*ast.SelectField
aggMapper map[*ast.AggregateFuncExpr]int
colMapper map[*ast.ColumnNameExpr]int
gbyItems []*ast.ByItem
outerSchemas []*expression.Schema
outerNames [][]*types.FieldName
curClause clauseCode
prevClause []clauseCode
}
func (a *havingWindowAndOrderbyExprResolver) pushCurClause(newClause clauseCode) {
a.prevClause = append(a.prevClause, a.curClause)
a.curClause = newClause
}
func (a *havingWindowAndOrderbyExprResolver) popCurClause() {
a.curClause = a.prevClause[len(a.prevClause)-1]
a.prevClause = a.prevClause[:len(a.prevClause)-1]
}
// Enter implements Visitor interface.
func (a *havingWindowAndOrderbyExprResolver) Enter(n ast.Node) (node ast.Node, skipChildren bool) {
switch n.(type) {
case *ast.AggregateFuncExpr:
a.inAggFunc = true
case *ast.WindowFuncExpr:
a.inWindowFunc = true
case *ast.WindowSpec:
a.inWindowSpec = true
case *driver.ParamMarkerExpr, *ast.ColumnNameExpr, *ast.ColumnName:
case *ast.SubqueryExpr, *ast.ExistsSubqueryExpr:
// Enter a new context, skip it.
// For example: select sum(c) + c + exists(select c from t) from t;
return n, true
case *ast.PartitionByClause:
a.pushCurClause(partitionByClause)
case *ast.OrderByClause:
if a.inWindowSpec {
a.pushCurClause(windowOrderByClause)
}
default:
a.inExpr = true
}
return n, false
}
func (a *havingWindowAndOrderbyExprResolver) resolveFromPlan(v *ast.ColumnNameExpr, p LogicalPlan) (int, error) {
idx, err := expression.FindFieldName(p.OutputNames(), v.Name)
if err != nil {
return -1, err
}
schemaCols, outputNames := p.Schema().Columns, p.OutputNames()
if idx < 0 {
// For SQL like `select t2.a from t1 join t2 using(a) where t2.a > 0
// order by t2.a`, the query plan will be `join->selection->sort`. The
// schema of selection will be `[t1.a]`, thus we need to recursively
// retrieve the `t2.a` from the underlying join.
switch x := p.(type) {
case *LogicalLimit, *LogicalSelection, *LogicalTopN, *LogicalSort, *LogicalMaxOneRow:
return a.resolveFromPlan(v, p.Children()[0])
case *LogicalJoin:
if len(x.fullNames) != 0 {
idx, err = expression.FindFieldName(x.fullNames, v.Name)
schemaCols, outputNames = x.fullSchema.Columns, x.fullNames
}
}
if err != nil || idx < 0 {
// nowhere to be found.
return -1, err
}
}
col := schemaCols[idx]
if col.IsHidden {
return -1, ErrUnknownColumn.GenWithStackByArgs(v.Name, clauseMsg[a.curClause])
}
name := outputNames[idx]
newColName := &ast.ColumnName{
Schema: name.DBName,
Table: name.TblName,
Name: name.ColName,
}
for i, field := range a.selectFields {
if c, ok := field.Expr.(*ast.ColumnNameExpr); ok && colMatch(c.Name, newColName) {
return i, nil
}
}
sf := &ast.SelectField{
Expr: &ast.ColumnNameExpr{Name: newColName},
Auxiliary: true,
}
// appended with new select fields. set them with flag.
if a.inAggFunc {
// should skip check in FD for only full group by.
sf.AuxiliaryColInAgg = true
} else if a.curClause == orderByClause {
// should skip check in FD for only full group by only when group by item are empty.
sf.AuxiliaryColInOrderBy = true
}
sf.Expr.SetType(col.GetType())
a.selectFields = append(a.selectFields, sf)
return len(a.selectFields) - 1, nil
}
// Leave implements Visitor interface.
func (a *havingWindowAndOrderbyExprResolver) Leave(n ast.Node) (node ast.Node, ok bool) {
switch v := n.(type) {
case *ast.AggregateFuncExpr:
a.inAggFunc = false
a.aggMapper[v] = len(a.selectFields)
a.selectFields = append(a.selectFields, &ast.SelectField{
Auxiliary: true,
Expr: v,
AsName: model.NewCIStr(fmt.Sprintf("sel_agg_%d", len(a.selectFields))),
})
case *ast.WindowFuncExpr:
a.inWindowFunc = false
if a.curClause == havingClause {
a.err = ErrWindowInvalidWindowFuncUse.GenWithStackByArgs(strings.ToLower(v.F))
return node, false
}
if a.curClause == orderByClause {
a.selectFields = append(a.selectFields, &ast.SelectField{
Auxiliary: true,
Expr: v,
AsName: model.NewCIStr(fmt.Sprintf("sel_window_%d", len(a.selectFields))),
})
}
case *ast.WindowSpec:
a.inWindowSpec = false
case *ast.PartitionByClause:
a.popCurClause()
case *ast.OrderByClause:
if a.inWindowSpec {
a.popCurClause()
}
case *ast.ColumnNameExpr:
resolveFieldsFirst := true
if a.inAggFunc || a.inWindowFunc || a.inWindowSpec || (a.curClause == orderByClause && a.inExpr) || a.curClause == fieldList {
resolveFieldsFirst = false
}
if !a.inAggFunc && a.curClause != orderByClause {
for _, item := range a.gbyItems {
if col, ok := item.Expr.(*ast.ColumnNameExpr); ok &&
(colMatch(v.Name, col.Name) || colMatch(col.Name, v.Name)) {
resolveFieldsFirst = false
break
}
}
}
var index int
if resolveFieldsFirst {
index, a.err = resolveFromSelectFields(v, a.selectFields, false)
if a.err != nil {
return node, false
}
if index != -1 && a.curClause == havingClause && ast.HasWindowFlag(a.selectFields[index].Expr) {
a.err = ErrWindowInvalidWindowFuncAliasUse.GenWithStackByArgs(v.Name.Name.O)
return node, false
}
if index == -1 {
if a.curClause == orderByClause {
index, a.err = a.resolveFromPlan(v, a.p)
} else if a.curClause == havingClause && v.Name.Table.L != "" {
// For SQLs like:
// select a from t b having b.a;
index, a.err = a.resolveFromPlan(v, a.p)
if a.err != nil {
return node, false
}
if index != -1 {
// For SQLs like:
// select a+1 from t having t.a;
field := a.selectFields[index]
if field.Auxiliary { // having can't use auxiliary field
index = -1
}
}
} else {
index, a.err = resolveFromSelectFields(v, a.selectFields, true)
}
}
} else {
// We should ignore the err when resolving from schema. Because we could resolve successfully
// when considering select fields.
var err error
index, err = a.resolveFromPlan(v, a.p)
_ = err
if index == -1 && a.curClause != fieldList &&
a.curClause != windowOrderByClause && a.curClause != partitionByClause {
index, a.err = resolveFromSelectFields(v, a.selectFields, false)
if index != -1 && a.curClause == havingClause && ast.HasWindowFlag(a.selectFields[index].Expr) {
a.err = ErrWindowInvalidWindowFuncAliasUse.GenWithStackByArgs(v.Name.Name.O)
return node, false
}
}
}
if a.err != nil {
return node, false
}
if index == -1 {
// If we can't find it any where, it may be a correlated columns.
for _, names := range a.outerNames {
idx, err1 := expression.FindFieldName(names, v.Name)
if err1 != nil {
a.err = err1
return node, false
}
if idx >= 0 {
return n, true
}
}
a.err = ErrUnknownColumn.GenWithStackByArgs(v.Name.OrigColName(), clauseMsg[a.curClause])
return node, false
}
if a.inAggFunc {
return a.selectFields[index].Expr, true
}
a.colMapper[v] = index
}
return n, true
}
// resolveHavingAndOrderBy will process aggregate functions and resolve the columns that don't exist in select fields.
// If we found some columns that are not in select fields, we will append it to select fields and update the colMapper.
// When we rewrite the order by / having expression, we will find column in map at first.
func (b *PlanBuilder) resolveHavingAndOrderBy(ctx context.Context, sel *ast.SelectStmt, p LogicalPlan) (
map[*ast.AggregateFuncExpr]int, map[*ast.AggregateFuncExpr]int, error) {
extractor := &havingWindowAndOrderbyExprResolver{
p: p,
selectFields: sel.Fields.Fields,
aggMapper: make(map[*ast.AggregateFuncExpr]int),
colMapper: b.colMapper,
outerSchemas: b.outerSchemas,
outerNames: b.outerNames,
}
if sel.GroupBy != nil {
extractor.gbyItems = sel.GroupBy.Items
}
// Extract agg funcs from having clause.
if sel.Having != nil {
extractor.curClause = havingClause
n, ok := sel.Having.Expr.Accept(extractor)
if !ok {
return nil, nil, errors.Trace(extractor.err)
}
sel.Having.Expr = n.(ast.ExprNode)
}
havingAggMapper := extractor.aggMapper
extractor.aggMapper = make(map[*ast.AggregateFuncExpr]int)
extractor.inExpr = false
// Extract agg funcs from order by clause.
if sel.OrderBy != nil {
extractor.curClause = orderByClause
for _, item := range sel.OrderBy.Items {
if ast.HasWindowFlag(item.Expr) {
continue
}
n, ok := item.Expr.Accept(extractor)
if !ok {
return nil, nil, errors.Trace(extractor.err)
}
item.Expr = n.(ast.ExprNode)
}
}
sel.Fields.Fields = extractor.selectFields
// this part is used to fetch correlated column from sub-query item in order-by clause, and append the origin
// auxiliary select filed in select list, otherwise, sub-query itself won't get the name resolved in outer schema.
if sel.OrderBy != nil {
for _, byItem := range sel.OrderBy.Items {
if _, ok := byItem.Expr.(*ast.SubqueryExpr); ok {
// correlated agg will be extracted completely latter.
_, np, err := b.rewrite(ctx, byItem.Expr, p, nil, true)
if err != nil {
return nil, nil, errors.Trace(err)
}
correlatedCols := ExtractCorrelatedCols4LogicalPlan(np)
for _, cone := range correlatedCols {
var colName *ast.ColumnName
for idx, pone := range p.Schema().Columns {
if cone.UniqueID == pone.UniqueID {
pname := p.OutputNames()[idx]
colName = &ast.ColumnName{
Schema: pname.DBName,
Table: pname.TblName,
Name: pname.ColName,
}
break
}
}
if colName != nil {
columnNameExpr := &ast.ColumnNameExpr{Name: colName}
for _, field := range sel.Fields.Fields {
if c, ok := field.Expr.(*ast.ColumnNameExpr); ok && colMatch(c.Name, columnNameExpr.Name) {
// deduplicate select fields: don't append it once it already has one.
columnNameExpr = nil
break
}
}
if columnNameExpr != nil {
sel.Fields.Fields = append(sel.Fields.Fields, &ast.SelectField{
Auxiliary: true,
Expr: columnNameExpr,
})
}
}
}
}
}
}
return havingAggMapper, extractor.aggMapper, nil
}
func (b *PlanBuilder) extractAggFuncsInExprs(exprs []ast.ExprNode) ([]*ast.AggregateFuncExpr, map[*ast.AggregateFuncExpr]int) {
extractor := &AggregateFuncExtractor{skipAggMap: b.correlatedAggMapper}
for _, expr := range exprs {
expr.Accept(extractor)
}
aggList := extractor.AggFuncs
totalAggMapper := make(map[*ast.AggregateFuncExpr]int, len(aggList))
for i, agg := range aggList {
totalAggMapper[agg] = i
}
return aggList, totalAggMapper
}
func (b *PlanBuilder) extractAggFuncsInSelectFields(fields []*ast.SelectField) ([]*ast.AggregateFuncExpr, map[*ast.AggregateFuncExpr]int) {
extractor := &AggregateFuncExtractor{skipAggMap: b.correlatedAggMapper}
for _, f := range fields {
n, _ := f.Expr.Accept(extractor)
f.Expr = n.(ast.ExprNode)
}
aggList := extractor.AggFuncs
totalAggMapper := make(map[*ast.AggregateFuncExpr]int, len(aggList))
for i, agg := range aggList {
totalAggMapper[agg] = i
}
return aggList, totalAggMapper
}
func (b *PlanBuilder) extractAggFuncsInByItems(byItems []*ast.ByItem) []*ast.AggregateFuncExpr {
extractor := &AggregateFuncExtractor{skipAggMap: b.correlatedAggMapper}
for _, f := range byItems {
n, _ := f.Expr.Accept(extractor)
f.Expr = n.(ast.ExprNode)
}
return extractor.AggFuncs
}
// extractCorrelatedAggFuncs extracts correlated aggregates which belong to outer query from aggregate function list.
func (b *PlanBuilder) extractCorrelatedAggFuncs(ctx context.Context, p LogicalPlan, aggFuncs []*ast.AggregateFuncExpr) (outer []*ast.AggregateFuncExpr, err error) {
corCols := make([]*expression.CorrelatedColumn, 0, len(aggFuncs))
cols := make([]*expression.Column, 0, len(aggFuncs))
aggMapper := make(map[*ast.AggregateFuncExpr]int)
for _, agg := range aggFuncs {
for _, arg := range agg.Args {
expr, _, err := b.rewrite(ctx, arg, p, aggMapper, true)
if err != nil {
return nil, err
}
corCols = append(corCols, expression.ExtractCorColumns(expr)...)
cols = append(cols, expression.ExtractColumns(expr)...)
}
if len(corCols) > 0 && len(cols) == 0 {
outer = append(outer, agg)
}
aggMapper[agg] = -1
corCols, cols = corCols[:0], cols[:0]
}
return
}
// resolveWindowFunction will process window functions and resolve the columns that don't exist in select fields.
func (b *PlanBuilder) resolveWindowFunction(sel *ast.SelectStmt, p LogicalPlan) (
map[*ast.AggregateFuncExpr]int, error) {
extractor := &havingWindowAndOrderbyExprResolver{
p: p,
selectFields: sel.Fields.Fields,
aggMapper: make(map[*ast.AggregateFuncExpr]int),
colMapper: b.colMapper,
outerSchemas: b.outerSchemas,
outerNames: b.outerNames,
}
extractor.curClause = fieldList
for _, field := range sel.Fields.Fields {
if !ast.HasWindowFlag(field.Expr) {
continue
}
n, ok := field.Expr.Accept(extractor)
if !ok {
return nil, extractor.err
}
field.Expr = n.(ast.ExprNode)
}
for _, spec := range sel.WindowSpecs {
_, ok := spec.Accept(extractor)
if !ok {
return nil, extractor.err
}
}
if sel.OrderBy != nil {
extractor.curClause = orderByClause
for _, item := range sel.OrderBy.Items {
if !ast.HasWindowFlag(item.Expr) {
continue
}
n, ok := item.Expr.Accept(extractor)
if !ok {
return nil, extractor.err
}
item.Expr = n.(ast.ExprNode)
}
}
sel.Fields.Fields = extractor.selectFields
return extractor.aggMapper, nil
}
// correlatedAggregateResolver visits Expr tree.
// It finds and collects all correlated aggregates which should be evaluated in the outer query.
type correlatedAggregateResolver struct {
ctx context.Context
err error
b *PlanBuilder
outerPlan LogicalPlan
// correlatedAggFuncs stores aggregate functions which belong to outer query
correlatedAggFuncs []*ast.AggregateFuncExpr
}
// Enter implements Visitor interface.
func (r *correlatedAggregateResolver) Enter(n ast.Node) (ast.Node, bool) {
if v, ok := n.(*ast.SelectStmt); ok {
if r.outerPlan != nil {
outerSchema := r.outerPlan.Schema()
r.b.outerSchemas = append(r.b.outerSchemas, outerSchema)
r.b.outerNames = append(r.b.outerNames, r.outerPlan.OutputNames())
}
r.err = r.resolveSelect(v)
return n, true
}
return n, false
}
// resolveSelect finds and collects correlated aggregates within the SELECT stmt.
// It resolves and builds FROM clause first to get a source plan, from which we can decide
// whether a column is correlated or not.
// Then it collects correlated aggregate from SELECT fields (including sub-queries), HAVING,
// ORDER BY, WHERE & GROUP BY.
// Finally it restore the original SELECT stmt.
func (r *correlatedAggregateResolver) resolveSelect(sel *ast.SelectStmt) (err error) {
if sel.With != nil {
l := len(r.b.outerCTEs)
defer func() {
r.b.outerCTEs = r.b.outerCTEs[:l]
}()
err := r.b.buildWith(r.ctx, sel.With)
if err != nil {
return err
}
}
// collect correlated aggregate from sub-queries inside FROM clause.
if err := r.collectFromTableRefs(sel.From); err != nil {
return err
}
p, err := r.b.buildTableRefs(r.ctx, sel.From)
if err != nil {
return err
}
// similar to process in PlanBuilder.buildSelect
originalFields := sel.Fields.Fields
sel.Fields.Fields, err = r.b.unfoldWildStar(p, sel.Fields.Fields)
if err != nil {
return err
}
if r.b.capFlag&canExpandAST != 0 {
originalFields = sel.Fields.Fields
}
hasWindowFuncField := r.b.detectSelectWindow(sel)
if hasWindowFuncField {
_, err = r.b.resolveWindowFunction(sel, p)
if err != nil {
return err
}
}
_, _, err = r.b.resolveHavingAndOrderBy(r.ctx, sel, p)
if err != nil {
return err
}
// find and collect correlated aggregates recursively in sub-queries
_, err = r.b.resolveCorrelatedAggregates(r.ctx, sel, p)
if err != nil {
return err
}
// collect from SELECT fields, HAVING, ORDER BY and window functions
if r.b.detectSelectAgg(sel) {
err = r.collectFromSelectFields(p, sel.Fields.Fields)
if err != nil {
return err
}
}
// collect from WHERE
err = r.collectFromWhere(p, sel.Where)
if err != nil {
return err
}
// collect from GROUP BY
err = r.collectFromGroupBy(p, sel.GroupBy)
if err != nil {
return err
}
// restore the sub-query
sel.Fields.Fields = originalFields
r.b.handleHelper.popMap()
return nil
}
func (r *correlatedAggregateResolver) collectFromTableRefs(from *ast.TableRefsClause) error {
if from == nil {
return nil
}
subResolver := &correlatedAggregateResolver{
ctx: r.ctx,
b: r.b,
}
_, ok := from.TableRefs.Accept(subResolver)
if !ok {
return subResolver.err
}
if len(subResolver.correlatedAggFuncs) == 0 {
return nil
}
r.correlatedAggFuncs = append(r.correlatedAggFuncs, subResolver.correlatedAggFuncs...)
return nil
}
func (r *correlatedAggregateResolver) collectFromSelectFields(p LogicalPlan, fields []*ast.SelectField) error {
aggList, _ := r.b.extractAggFuncsInSelectFields(fields)
r.b.curClause = fieldList
outerAggFuncs, err := r.b.extractCorrelatedAggFuncs(r.ctx, p, aggList)
if err != nil {
return nil
}
r.correlatedAggFuncs = append(r.correlatedAggFuncs, outerAggFuncs...)
return nil
}
func (r *correlatedAggregateResolver) collectFromGroupBy(p LogicalPlan, groupBy *ast.GroupByClause) error {
if groupBy == nil {
return nil
}
aggList := r.b.extractAggFuncsInByItems(groupBy.Items)
r.b.curClause = groupByClause
outerAggFuncs, err := r.b.extractCorrelatedAggFuncs(r.ctx, p, aggList)
if err != nil {
return nil
}
r.correlatedAggFuncs = append(r.correlatedAggFuncs, outerAggFuncs...)
return nil
}
func (r *correlatedAggregateResolver) collectFromWhere(p LogicalPlan, where ast.ExprNode) error {
if where == nil {
return nil
}
extractor := &AggregateFuncExtractor{skipAggMap: r.b.correlatedAggMapper}
_, _ = where.Accept(extractor)
r.b.curClause = whereClause
outerAggFuncs, err := r.b.extractCorrelatedAggFuncs(r.ctx, p, extractor.AggFuncs)
if err != nil {
return err
}
r.correlatedAggFuncs = append(r.correlatedAggFuncs, outerAggFuncs...)
return nil
}
// Leave implements Visitor interface.
func (r *correlatedAggregateResolver) Leave(n ast.Node) (ast.Node, bool) {
if _, ok := n.(*ast.SelectStmt); ok {
if r.outerPlan != nil {
r.b.outerSchemas = r.b.outerSchemas[0 : len(r.b.outerSchemas)-1]
r.b.outerNames = r.b.outerNames[0 : len(r.b.outerNames)-1]
}
}
return n, r.err == nil
}
// resolveCorrelatedAggregates finds and collects all correlated aggregates which should be evaluated
// in the outer query from all the sub-queries inside SELECT fields.
func (b *PlanBuilder) resolveCorrelatedAggregates(ctx context.Context, sel *ast.SelectStmt, p LogicalPlan) (map[*ast.AggregateFuncExpr]int, error) {
resolver := &correlatedAggregateResolver{
ctx: ctx,
b: b,
outerPlan: p,
}
correlatedAggList := make([]*ast.AggregateFuncExpr, 0)
for _, field := range sel.Fields.Fields {
_, ok := field.Expr.Accept(resolver)
if !ok {
return nil, resolver.err
}
correlatedAggList = append(correlatedAggList, resolver.correlatedAggFuncs...)
}
if sel.Having != nil {
_, ok := sel.Having.Expr.Accept(resolver)
if !ok {
return nil, resolver.err
}
correlatedAggList = append(correlatedAggList, resolver.correlatedAggFuncs...)
}
if sel.OrderBy != nil {
for _, item := range sel.OrderBy.Items {
_, ok := item.Expr.Accept(resolver)
if !ok {
return nil, resolver.err
}
correlatedAggList = append(correlatedAggList, resolver.correlatedAggFuncs...)
}
}
correlatedAggMap := make(map[*ast.AggregateFuncExpr]int)
for _, aggFunc := range correlatedAggList {
colMap := make(map[*types.FieldName]struct{}, len(p.Schema().Columns))
allColFromAggExprNode(p, aggFunc, colMap)
for k := range colMap {
colName := &ast.ColumnName{
Schema: k.DBName,
Table: k.TblName,
Name: k.ColName,
}
// Add the column referred in the agg func into the select list. So that we can resolve the agg func correctly.
// And we need set the AuxiliaryColInAgg to true to help our only_full_group_by checker work correctly.
sel.Fields.Fields = append(sel.Fields.Fields, &ast.SelectField{
Auxiliary: true,
AuxiliaryColInAgg: true,
Expr: &ast.ColumnNameExpr{Name: colName},
})
}
correlatedAggMap[aggFunc] = len(sel.Fields.Fields)
sel.Fields.Fields = append(sel.Fields.Fields, &ast.SelectField{
Auxiliary: true,
Expr: aggFunc,
AsName: model.NewCIStr(fmt.Sprintf("sel_subq_agg_%d", len(sel.Fields.Fields))),
})
}
return correlatedAggMap, nil
}
// gbyResolver resolves group by items from select fields.
type gbyResolver struct {
ctx sessionctx.Context
fields []*ast.SelectField
schema *expression.Schema
names []*types.FieldName
err error
inExpr bool
isParam bool
skipAggMap map[*ast.AggregateFuncExpr]*expression.CorrelatedColumn
exprDepth int // exprDepth is the depth of current expression in expression tree.
}
func (g *gbyResolver) Enter(inNode ast.Node) (ast.Node, bool) {
g.exprDepth++
switch n := inNode.(type) {
case *ast.SubqueryExpr, *ast.CompareSubqueryExpr, *ast.ExistsSubqueryExpr:
return inNode, true
case *driver.ParamMarkerExpr:
g.isParam = true
if g.exprDepth == 1 {
_, isNull, isExpectedType := getUintFromNode(g.ctx, n)
// For constant uint expression in top level, it should be treated as position expression.
if !isNull && isExpectedType {
return expression.ConstructPositionExpr(n), true
}
}
return n, true
case *driver.ValueExpr, *ast.ColumnNameExpr, *ast.ParenthesesExpr, *ast.ColumnName:
default:
g.inExpr = true
}
return inNode, false
}
func (g *gbyResolver) Leave(inNode ast.Node) (ast.Node, bool) {
extractor := &AggregateFuncExtractor{skipAggMap: g.skipAggMap}
switch v := inNode.(type) {
case *ast.ColumnNameExpr:
idx, err := expression.FindFieldName(g.names, v.Name)
if idx < 0 || !g.inExpr {
var index int
index, g.err = resolveFromSelectFields(v, g.fields, false)
if g.err != nil {
g.err = ErrAmbiguous.GenWithStackByArgs(v.Name.Name.L, clauseMsg[groupByClause])
return inNode, false
}
if idx >= 0 {
return inNode, true
}
if index != -1 {
ret := g.fields[index].Expr
ret.Accept(extractor)
if len(extractor.AggFuncs) != 0 {
err = ErrIllegalReference.GenWithStackByArgs(v.Name.OrigColName(), "reference to group function")
} else if ast.HasWindowFlag(ret) {
err = ErrIllegalReference.GenWithStackByArgs(v.Name.OrigColName(), "reference to window function")
} else {
return ret, true
}
}
g.err = err
return inNode, false
}
case *ast.PositionExpr:
pos, isNull, err := expression.PosFromPositionExpr(g.ctx, v)
if err != nil {
g.err = ErrUnknown.GenWithStackByArgs()
}
if err != nil || isNull {
return inNode, false
}
if pos < 1 || pos > len(g.fields) {
g.err = errors.Errorf("Unknown column '%d' in 'group statement'", pos)
return inNode, false
}
ret := g.fields[pos-1].Expr
ret.Accept(extractor)
if len(extractor.AggFuncs) != 0 || ast.HasWindowFlag(ret) {
fieldName := g.fields[pos-1].AsName.String()
if fieldName == "" {
fieldName = g.fields[pos-1].Text()
}
g.err = ErrWrongGroupField.GenWithStackByArgs(fieldName)
return inNode, false
}
return ret, true
case *ast.ValuesExpr:
if v.Column == nil {
g.err = ErrUnknownColumn.GenWithStackByArgs("", "VALUES() function")
}
}
return inNode, true
}
func tblInfoFromCol(from ast.ResultSetNode, name *types.FieldName) *model.TableInfo {
var tableList []*ast.TableName
tableList = extractTableList(from, tableList, true)
for _, field := range tableList {
if field.Name.L == name.TblName.L {
return field.TableInfo
}
}
return nil
}
func buildFuncDependCol(p LogicalPlan, cond ast.ExprNode) (*types.FieldName, *types.FieldName, error) {
binOpExpr, ok := cond.(*ast.BinaryOperationExpr)
if !ok {
return nil, nil, nil
}
if binOpExpr.Op != opcode.EQ {
return nil, nil, nil
}
lColExpr, ok := binOpExpr.L.(*ast.ColumnNameExpr)
if !ok {
return nil, nil, nil
}
rColExpr, ok := binOpExpr.R.(*ast.ColumnNameExpr)
if !ok {
return nil, nil, nil
}
lIdx, err := expression.FindFieldName(p.OutputNames(), lColExpr.Name)
if err != nil {
return nil, nil, err
}
rIdx, err := expression.FindFieldName(p.OutputNames(), rColExpr.Name)
if err != nil {
return nil, nil, err
}
if lIdx == -1 {
return nil, nil, ErrUnknownColumn.GenWithStackByArgs(lColExpr.Name, "where clause")
}
if rIdx == -1 {
return nil, nil, ErrUnknownColumn.GenWithStackByArgs(rColExpr.Name, "where clause")
}
return p.OutputNames()[lIdx], p.OutputNames()[rIdx], nil
}
func buildWhereFuncDepend(p LogicalPlan, where ast.ExprNode) (map[*types.FieldName]*types.FieldName, error) {
whereConditions := splitWhere(where)
colDependMap := make(map[*types.FieldName]*types.FieldName, 2*len(whereConditions))
for _, cond := range whereConditions {
lCol, rCol, err := buildFuncDependCol(p, cond)
if err != nil {
return nil, err
}
if lCol == nil || rCol == nil {
continue
}
colDependMap[lCol] = rCol
colDependMap[rCol] = lCol
}
return colDependMap, nil
}
func buildJoinFuncDepend(p LogicalPlan, from ast.ResultSetNode) (map[*types.FieldName]*types.FieldName, error) {
switch x := from.(type) {
case *ast.Join:
if x.On == nil {
return nil, nil
}
onConditions := splitWhere(x.On.Expr)
colDependMap := make(map[*types.FieldName]*types.FieldName, len(onConditions))
for _, cond := range onConditions {
lCol, rCol, err := buildFuncDependCol(p, cond)
if err != nil {
return nil, err
}
if lCol == nil || rCol == nil {
continue
}
lTbl := tblInfoFromCol(x.Left, lCol)
if lTbl == nil {
lCol, rCol = rCol, lCol
}
switch x.Tp {
case ast.CrossJoin:
colDependMap[lCol] = rCol
colDependMap[rCol] = lCol
case ast.LeftJoin:
colDependMap[rCol] = lCol
case ast.RightJoin:
colDependMap[lCol] = rCol
}
}
return colDependMap, nil
default:
return nil, nil
}
}
func checkColFuncDepend(
p LogicalPlan,
name *types.FieldName,
tblInfo *model.TableInfo,
gbyOrSingleValueColNames map[*types.FieldName]struct{},
whereDependNames, joinDependNames map[*types.FieldName]*types.FieldName,
) bool {
for _, index := range tblInfo.Indices {
if !index.Unique {
continue
}
funcDepend := true
// if all columns of some unique/pri indexes are determined, all columns left are check-passed.
for _, indexCol := range index.Columns {
iColInfo := tblInfo.Columns[indexCol.Offset]
if !mysql.HasNotNullFlag(iColInfo.GetFlag()) {
funcDepend = false
break
}
cn := &ast.ColumnName{
Schema: name.DBName,
Table: name.TblName,
Name: iColInfo.Name,
}
iIdx, err := expression.FindFieldName(p.OutputNames(), cn)
if err != nil || iIdx < 0 {
funcDepend = false
break
}
iName := p.OutputNames()[iIdx]
if _, ok := gbyOrSingleValueColNames[iName]; ok {
continue
}
if wCol, ok := whereDependNames[iName]; ok {
if _, ok = gbyOrSingleValueColNames[wCol]; ok {
continue
}
}
if jCol, ok := joinDependNames[iName]; ok {
if _, ok = gbyOrSingleValueColNames[jCol]; ok {
continue
}
}
funcDepend = false
break
}
if funcDepend {
return true
}
}
primaryFuncDepend := true
hasPrimaryField := false
for _, colInfo := range tblInfo.Columns {
if !mysql.HasPriKeyFlag(colInfo.GetFlag()) {
continue
}
hasPrimaryField = true
pkName := &ast.ColumnName{
Schema: name.DBName,
Table: name.TblName,
Name: colInfo.Name,
}
pIdx, err := expression.FindFieldName(p.OutputNames(), pkName)
// It is possible that `pIdx < 0` and here is a case.
// ```
// CREATE TABLE `BB` (
// `pk` int(11) NOT NULL AUTO_INCREMENT,
// `col_int_not_null` int NOT NULL,
// PRIMARY KEY (`pk`)
// );
//
// SELECT OUTR . col2 AS X
// FROM
// BB AS OUTR2
// INNER JOIN
// (SELECT col_int_not_null AS col1,
// pk AS col2
// FROM BB) AS OUTR ON OUTR2.col_int_not_null = OUTR.col1
// GROUP BY OUTR2.col_int_not_null;
// ```
// When we enter `checkColFuncDepend`, `pkName.Table` is `OUTR` which is an alias, while `pkName.Name` is `pk`
// which is a original name. Hence `expression.FindFieldName` will fail and `pIdx` will be less than 0.
// Currently, when we meet `pIdx < 0`, we directly regard `primaryFuncDepend` as false and jump out. This way is
// easy to implement but makes only-full-group-by checker not smart enough. Later we will refactor only-full-group-by
// checker and resolve the inconsistency between the alias table name and the original column name.
if err != nil || pIdx < 0 {
primaryFuncDepend = false
break
}
pCol := p.OutputNames()[pIdx]
if _, ok := gbyOrSingleValueColNames[pCol]; ok {
continue
}
if wCol, ok := whereDependNames[pCol]; ok {
if _, ok = gbyOrSingleValueColNames[wCol]; ok {
continue
}
}
if jCol, ok := joinDependNames[pCol]; ok {
if _, ok = gbyOrSingleValueColNames[jCol]; ok {
continue
}
}
primaryFuncDepend = false
break
}
return primaryFuncDepend && hasPrimaryField
}
// ErrExprLoc is for generate the ErrFieldNotInGroupBy error info
type ErrExprLoc struct {
Offset int
Loc string
}
func checkExprInGroupByOrIsSingleValue(
p LogicalPlan,
expr ast.ExprNode,
offset int,
loc string,
gbyOrSingleValueColNames map[*types.FieldName]struct{},
gbyExprs []ast.ExprNode,
notInGbyOrSingleValueColNames map[*types.FieldName]ErrExprLoc,
) {
if _, ok := expr.(*ast.AggregateFuncExpr); ok {
return
}
if _, ok := expr.(*ast.ColumnNameExpr); !ok {
for _, gbyExpr := range gbyExprs {
if ast.ExpressionDeepEqual(gbyExpr, expr) {
return
}
}
}
// Function `any_value` can be used in aggregation, even `ONLY_FULL_GROUP_BY` is set.
// See https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_any-value for details
if f, ok := expr.(*ast.FuncCallExpr); ok {
if f.FnName.L == ast.AnyValue {
return
}
}
colMap := make(map[*types.FieldName]struct{}, len(p.Schema().Columns))
allColFromExprNode(p, expr, colMap)
for col := range colMap {
if _, ok := gbyOrSingleValueColNames[col]; !ok {
notInGbyOrSingleValueColNames[col] = ErrExprLoc{Offset: offset, Loc: loc}
}
}
}
func (b *PlanBuilder) checkOnlyFullGroupBy(p LogicalPlan, sel *ast.SelectStmt) (err error) {
if sel.GroupBy != nil {
err = b.checkOnlyFullGroupByWithGroupClause(p, sel)
} else {
err = b.checkOnlyFullGroupByWithOutGroupClause(p, sel)
}
return err
}
func addGbyOrSingleValueColName(p LogicalPlan, colName *ast.ColumnName, gbyOrSingleValueColNames map[*types.FieldName]struct{}) {
idx, err := expression.FindFieldName(p.OutputNames(), colName)
if err != nil || idx < 0 {
return
}
gbyOrSingleValueColNames[p.OutputNames()[idx]] = struct{}{}
}
func extractSingeValueColNamesFromWhere(p LogicalPlan, where ast.ExprNode, gbyOrSingleValueColNames map[*types.FieldName]struct{}) {
whereConditions := splitWhere(where)
for _, cond := range whereConditions {
binOpExpr, ok := cond.(*ast.BinaryOperationExpr)
if !ok || binOpExpr.Op != opcode.EQ {
continue
}
if colExpr, ok := binOpExpr.L.(*ast.ColumnNameExpr); ok {
if _, ok := binOpExpr.R.(ast.ValueExpr); ok {
addGbyOrSingleValueColName(p, colExpr.Name, gbyOrSingleValueColNames)
}
} else if colExpr, ok := binOpExpr.R.(*ast.ColumnNameExpr); ok {
if _, ok := binOpExpr.L.(ast.ValueExpr); ok {
addGbyOrSingleValueColName(p, colExpr.Name, gbyOrSingleValueColNames)
}
}
}
}
func (b *PlanBuilder) checkOnlyFullGroupByWithGroupClause(p LogicalPlan, sel *ast.SelectStmt) error {
gbyOrSingleValueColNames := make(map[*types.FieldName]struct{}, len(sel.Fields.Fields))
gbyExprs := make([]ast.ExprNode, 0, len(sel.Fields.Fields))
for _, byItem := range sel.GroupBy.Items {
expr := getInnerFromParenthesesAndUnaryPlus(byItem.Expr)
if colExpr, ok := expr.(*ast.ColumnNameExpr); ok {
addGbyOrSingleValueColName(p, colExpr.Name, gbyOrSingleValueColNames)
} else {
gbyExprs = append(gbyExprs, expr)
}
}
// MySQL permits a nonaggregate column not named in a GROUP BY clause when ONLY_FULL_GROUP_BY SQL mode is enabled,
// provided that this column is limited to a single value.
// See https://dev.mysql.com/doc/refman/5.7/en/group-by-handling.html for details.
extractSingeValueColNamesFromWhere(p, sel.Where, gbyOrSingleValueColNames)
notInGbyOrSingleValueColNames := make(map[*types.FieldName]ErrExprLoc, len(sel.Fields.Fields))
for offset, field := range sel.Fields.Fields {
if field.Auxiliary {
continue
}
checkExprInGroupByOrIsSingleValue(p, getInnerFromParenthesesAndUnaryPlus(field.Expr), offset, ErrExprInSelect, gbyOrSingleValueColNames, gbyExprs, notInGbyOrSingleValueColNames)
}
if sel.OrderBy != nil {
for offset, item := range sel.OrderBy.Items {
if colName, ok := item.Expr.(*ast.ColumnNameExpr); ok {
index, err := resolveFromSelectFields(colName, sel.Fields.Fields, false)
if err != nil {
return err
}
// If the ByItem is in fields list, it has been checked already in above.
if index >= 0 {
continue
}
}
checkExprInGroupByOrIsSingleValue(p, getInnerFromParenthesesAndUnaryPlus(item.Expr), offset, ErrExprInOrderBy, gbyOrSingleValueColNames, gbyExprs, notInGbyOrSingleValueColNames)
}
}
if len(notInGbyOrSingleValueColNames) == 0 {
return nil
}
whereDepends, err := buildWhereFuncDepend(p, sel.Where)
if err != nil {
return err
}
joinDepends, err := buildJoinFuncDepend(p, sel.From.TableRefs)
if err != nil {
return err
}
tblMap := make(map[*model.TableInfo]struct{}, len(notInGbyOrSingleValueColNames))
for name, errExprLoc := range notInGbyOrSingleValueColNames {
tblInfo := tblInfoFromCol(sel.From.TableRefs, name)
if tblInfo == nil {
continue
}
if _, ok := tblMap[tblInfo]; ok {
continue
}
if checkColFuncDepend(p, name, tblInfo, gbyOrSingleValueColNames, whereDepends, joinDepends) {
tblMap[tblInfo] = struct{}{}
continue
}
switch errExprLoc.Loc {
case ErrExprInSelect:
return ErrFieldNotInGroupBy.GenWithStackByArgs(errExprLoc.Offset+1, errExprLoc.Loc, name.DBName.O+"."+name.TblName.O+"."+name.OrigColName.O)
case ErrExprInOrderBy:
return ErrFieldNotInGroupBy.GenWithStackByArgs(errExprLoc.Offset+1, errExprLoc.Loc, sel.OrderBy.Items[errExprLoc.Offset].Expr.Text())
}
return nil
}
return nil
}
func (b *PlanBuilder) checkOnlyFullGroupByWithOutGroupClause(p LogicalPlan, sel *ast.SelectStmt) error {
resolver := colResolverForOnlyFullGroupBy{
firstOrderByAggColIdx: -1,
}
resolver.curClause = fieldList
for idx, field := range sel.Fields.Fields {
resolver.exprIdx = idx
field.Accept(&resolver)
}
if len(resolver.nonAggCols) > 0 {
if sel.Having != nil {
sel.Having.Expr.Accept(&resolver)
}
if sel.OrderBy != nil {
resolver.curClause = orderByClause
for idx, byItem := range sel.OrderBy.Items {
resolver.exprIdx = idx
byItem.Expr.Accept(&resolver)
}
}
}
if resolver.firstOrderByAggColIdx != -1 && len(resolver.nonAggCols) > 0 {
// SQL like `select a from t where a = 1 order by count(b)` is illegal.
return ErrAggregateOrderNonAggQuery.GenWithStackByArgs(resolver.firstOrderByAggColIdx + 1)
}
if !resolver.hasAggFuncOrAnyValue || len(resolver.nonAggCols) == 0 {
return nil
}
singleValueColNames := make(map[*types.FieldName]struct{}, len(sel.Fields.Fields))
extractSingeValueColNamesFromWhere(p, sel.Where, singleValueColNames)
whereDepends, err := buildWhereFuncDepend(p, sel.Where)
if err != nil {
return err
}
joinDepends, err := buildJoinFuncDepend(p, sel.From.TableRefs)
if err != nil {
return err
}
tblMap := make(map[*model.TableInfo]struct{}, len(resolver.nonAggCols))
for i, colName := range resolver.nonAggCols {
idx, err := expression.FindFieldName(p.OutputNames(), colName)
if err != nil || idx < 0 {
return ErrMixOfGroupFuncAndFields.GenWithStackByArgs(resolver.nonAggColIdxs[i]+1, colName.Name.O)
}
fieldName := p.OutputNames()[idx]
if _, ok := singleValueColNames[fieldName]; ok {
continue
}
tblInfo := tblInfoFromCol(sel.From.TableRefs, fieldName)
if tblInfo == nil {
continue
}
if _, ok := tblMap[tblInfo]; ok {
continue
}
if checkColFuncDepend(p, fieldName, tblInfo, singleValueColNames, whereDepends, joinDepends) {
tblMap[tblInfo] = struct{}{}
continue
}
return ErrMixOfGroupFuncAndFields.GenWithStackByArgs(resolver.nonAggColIdxs[i]+1, colName.Name.O)
}
return nil
}
// colResolverForOnlyFullGroupBy visits Expr tree to find out if an Expr tree is an aggregation function.
// If so, find out the first column name that not in an aggregation function.
type colResolverForOnlyFullGroupBy struct {
nonAggCols []*ast.ColumnName
exprIdx int
nonAggColIdxs []int
hasAggFuncOrAnyValue bool
firstOrderByAggColIdx int
curClause clauseCode
}
func (c *colResolverForOnlyFullGroupBy) Enter(node ast.Node) (ast.Node, bool) {
switch t := node.(type) {
case *ast.AggregateFuncExpr:
c.hasAggFuncOrAnyValue = true
if c.curClause == orderByClause {
c.firstOrderByAggColIdx = c.exprIdx
}
return node, true
case *ast.FuncCallExpr:
// enable function `any_value` in aggregation even `ONLY_FULL_GROUP_BY` is set
if t.FnName.L == ast.AnyValue {
c.hasAggFuncOrAnyValue = true
return node, true
}
case *ast.ColumnNameExpr:
c.nonAggCols = append(c.nonAggCols, t.Name)
c.nonAggColIdxs = append(c.nonAggColIdxs, c.exprIdx)
return node, true
case *ast.SubqueryExpr:
return node, true
}
return node, false
}
func (c *colResolverForOnlyFullGroupBy) Leave(node ast.Node) (ast.Node, bool) {
return node, true
}
type aggColNameResolver struct {
colNameResolver
}
func (c *aggColNameResolver) Enter(inNode ast.Node) (ast.Node, bool) {
if _, ok := inNode.(*ast.ColumnNameExpr); ok {
return inNode, true
}
return inNode, false
}
func allColFromAggExprNode(p LogicalPlan, n ast.Node, names map[*types.FieldName]struct{}) {
extractor := &aggColNameResolver{
colNameResolver: colNameResolver{
p: p,
names: names,
},
}
n.Accept(extractor)
}
type colNameResolver struct {
p LogicalPlan
names map[*types.FieldName]struct{}
}
func (c *colNameResolver) Enter(inNode ast.Node) (ast.Node, bool) {
switch inNode.(type) {
case *ast.ColumnNameExpr, *ast.SubqueryExpr, *ast.AggregateFuncExpr:
return inNode, true
}
return inNode, false
}
func (c *colNameResolver) Leave(inNode ast.Node) (ast.Node, bool) {
if v, ok := inNode.(*ast.ColumnNameExpr); ok {
idx, err := expression.FindFieldName(c.p.OutputNames(), v.Name)
if err == nil && idx >= 0 {
c.names[c.p.OutputNames()[idx]] = struct{}{}
}
}
return inNode, true
}
func allColFromExprNode(p LogicalPlan, n ast.Node, names map[*types.FieldName]struct{}) {
extractor := &colNameResolver{
p: p,
names: names,
}
n.Accept(extractor)
}
func (b *PlanBuilder) resolveGbyExprs(ctx context.Context, p LogicalPlan, gby *ast.GroupByClause, fields []*ast.SelectField) (LogicalPlan, []expression.Expression, error) {
b.curClause = groupByClause
exprs := make([]expression.Expression, 0, len(gby.Items))
resolver := &gbyResolver{
ctx: b.ctx,
fields: fields,
schema: p.Schema(),
names: p.OutputNames(),
skipAggMap: b.correlatedAggMapper,
}
for _, item := range gby.Items {
resolver.inExpr = false
resolver.exprDepth = 0
resolver.isParam = false
retExpr, _ := item.Expr.Accept(resolver)
if resolver.err != nil {
return nil, nil, errors.Trace(resolver.err)
}
if !resolver.isParam {
item.Expr = retExpr.(ast.ExprNode)
}
itemExpr := retExpr.(ast.ExprNode)
expr, np, err := b.rewrite(ctx, itemExpr, p, nil, true)
if err != nil {
return nil, nil, err
}
exprs = append(exprs, expr)
p = np
}
return p, exprs, nil
}
func (b *PlanBuilder) unfoldWildStar(p LogicalPlan, selectFields []*ast.SelectField) (resultList []*ast.SelectField, err error) {
join, isJoin := p.(*LogicalJoin)
for i, field := range selectFields {
if field.WildCard == nil {
resultList = append(resultList, field)
continue
}
if field.WildCard.Table.L == "" && i > 0 {
return nil, ErrInvalidWildCard
}
list := unfoldWildStar(field, p.OutputNames(), p.Schema().Columns)
// For sql like `select t1.*, t2.* from t1 join t2 using(a)` or `select t1.*, t2.* from t1 natual join t2`,
// the schema of the Join doesn't contain enough columns because the join keys are coalesced in this schema.
// We should collect the columns from the fullSchema.
if isJoin && join.fullSchema != nil && field.WildCard.Table.L != "" {
list = unfoldWildStar(field, join.fullNames, join.fullSchema.Columns)
}
if len(list) == 0 {
return nil, ErrBadTable.GenWithStackByArgs(field.WildCard.Table)
}
resultList = append(resultList, list...)
}
return resultList, nil
}
func unfoldWildStar(field *ast.SelectField, outputName types.NameSlice, column []*expression.Column) (resultList []*ast.SelectField) {
dbName := field.WildCard.Schema
tblName := field.WildCard.Table
for i, name := range outputName {
col := column[i]
if col.IsHidden {
continue
}
if (dbName.L == "" || dbName.L == name.DBName.L) &&
(tblName.L == "" || tblName.L == name.TblName.L) &&
col.ID != model.ExtraHandleID && col.ID != model.ExtraPidColID && col.ID != model.ExtraPhysTblID {
colName := &ast.ColumnNameExpr{
Name: &ast.ColumnName{
Schema: name.DBName,
Table: name.TblName,
Name: name.ColName,
}}
colName.SetType(col.GetType())
field := &ast.SelectField{Expr: colName}
field.SetText(nil, name.ColName.O)
resultList = append(resultList, field)
}
}
return resultList
}
func (b *PlanBuilder) addAliasName(ctx context.Context, selectStmt *ast.SelectStmt, p LogicalPlan) (resultList []*ast.SelectField, err error) {
selectFields := selectStmt.Fields.Fields
projOutNames := make([]*types.FieldName, 0, len(selectFields))
for _, field := range selectFields {
colNameField, isColumnNameExpr := field.Expr.(*ast.ColumnNameExpr)
if isColumnNameExpr {
colName := colNameField.Name.Name
if field.AsName.L != "" {
colName = field.AsName
}
projOutNames = append(projOutNames, &types.FieldName{
TblName: colNameField.Name.Table,
OrigTblName: colNameField.Name.Table,
ColName: colName,
OrigColName: colNameField.Name.Name,
DBName: colNameField.Name.Schema,
})
} else {
// create view v as select name_const('col', 100);
// The column in v should be 'col', so we call `buildProjectionField` to handle this.
_, name, err := b.buildProjectionField(ctx, p, field, nil)
if err != nil {
return nil, err
}
projOutNames = append(projOutNames, name)
}
}
// dedupMap is used for renaming a duplicated anonymous column
dedupMap := make(map[string]int)
anonymousFields := make([]bool, len(selectFields))
for i, field := range selectFields {
newField := *field
if newField.AsName.L == "" {
newField.AsName = projOutNames[i].ColName
}
if _, ok := field.Expr.(*ast.ColumnNameExpr); !ok && field.AsName.L == "" {
anonymousFields[i] = true
} else {
anonymousFields[i] = false
// dedupMap should be inited with all non-anonymous fields before renaming other duplicated anonymous fields
dedupMap[newField.AsName.L] = 0
}
resultList = append(resultList, &newField)
}
// We should rename duplicated anonymous fields in the first SelectStmt of CreateViewStmt
// See: https://github.com/pingcap/tidb/issues/29326
if selectStmt.AsViewSchema {
for i, field := range resultList {
if !anonymousFields[i] {
continue
}
oldName := field.AsName
if dup, ok := dedupMap[field.AsName.L]; ok {
if dup == 0 {
field.AsName = model.NewCIStr(fmt.Sprintf("Name_exp_%s", field.AsName.O))
} else {
field.AsName = model.NewCIStr(fmt.Sprintf("Name_exp_%d_%s", dup, field.AsName.O))
}
dedupMap[oldName.L] = dup + 1
} else {
dedupMap[oldName.L] = 0
}
}
}
return resultList, nil
}
func (b *PlanBuilder) pushHintWithoutTableWarning(hint *ast.TableOptimizerHint) {
var sb strings.Builder
ctx := format.NewRestoreCtx(0, &sb)
if err := hint.Restore(ctx); err != nil {
return
}
errMsg := fmt.Sprintf("Hint %s is inapplicable. Please specify the table names in the arguments.", sb.String())
b.ctx.GetSessionVars().StmtCtx.AppendWarning(ErrInternal.GenWithStack(errMsg))
}
func (b *PlanBuilder) pushTableHints(hints []*ast.TableOptimizerHint, currentLevel int) {
hints = b.hintProcessor.GetCurrentStmtHints(hints, currentLevel)
var (
sortMergeTables, INLJTables, INLHJTables, INLMJTables, hashJoinTables, BCTables []hintTableInfo
indexHintList, indexMergeHintList []indexHintInfo
tiflashTables, tikvTables []hintTableInfo
aggHints aggHintInfo
timeRangeHint ast.HintTimeRange
limitHints limitHintInfo
MergeHints MergeHintInfo
leadingJoinOrder []hintTableInfo
hjBuildTables, hjProbeTables []hintTableInfo
leadingHintCnt int
)
for _, hint := range hints {
// Set warning for the hint that requires the table name.
switch hint.HintName.L {
case TiDBMergeJoin, HintSMJ, TiDBIndexNestedLoopJoin, HintINLJ, HintINLHJ, HintINLMJ,
TiDBHashJoin, HintHJ, HintUseIndex, HintIgnoreIndex, HintForceIndex, HintIndexMerge, HintLeading:
if len(hint.Tables) == 0 {
b.pushHintWithoutTableWarning(hint)
continue
}
}
switch hint.HintName.L {
case TiDBMergeJoin, HintSMJ:
sortMergeTables = append(sortMergeTables, tableNames2HintTableInfo(b.ctx, hint.HintName.L, hint.Tables, b.hintProcessor, currentLevel)...)
case TiDBBroadCastJoin, HintBCJ:
BCTables = append(BCTables, tableNames2HintTableInfo(b.ctx, hint.HintName.L, hint.Tables, b.hintProcessor, currentLevel)...)
case TiDBIndexNestedLoopJoin, HintINLJ:
INLJTables = append(INLJTables, tableNames2HintTableInfo(b.ctx, hint.HintName.L, hint.Tables, b.hintProcessor, currentLevel)...)
case HintINLHJ:
INLHJTables = append(INLHJTables, tableNames2HintTableInfo(b.ctx, hint.HintName.L, hint.Tables, b.hintProcessor, currentLevel)...)
case HintINLMJ:
INLMJTables = append(INLMJTables, tableNames2HintTableInfo(b.ctx, hint.HintName.L, hint.Tables, b.hintProcessor, currentLevel)...)
case TiDBHashJoin, HintHJ:
hashJoinTables = append(hashJoinTables, tableNames2HintTableInfo(b.ctx, hint.HintName.L, hint.Tables, b.hintProcessor, currentLevel)...)
case HintHashJoinBuild:
hjBuildTables = append(hjBuildTables, tableNames2HintTableInfo(b.ctx, hint.HintName.L, hint.Tables, b.hintProcessor, currentLevel)...)
case HintHashJoinProbe:
hjProbeTables = append(hjProbeTables, tableNames2HintTableInfo(b.ctx, hint.HintName.L, hint.Tables, b.hintProcessor, currentLevel)...)
case HintHashAgg:
aggHints.preferAggType |= preferHashAgg
case HintStreamAgg:
aggHints.preferAggType |= preferStreamAgg
case HintAggToCop:
aggHints.preferAggToCop = true
case HintUseIndex:
dbName := hint.Tables[0].DBName
if dbName.L == "" {
dbName = model.NewCIStr(b.ctx.GetSessionVars().CurrentDB)
}
indexHintList = append(indexHintList, indexHintInfo{
dbName: dbName,
tblName: hint.Tables[0].TableName,
partitions: hint.Tables[0].PartitionList,
indexHint: &ast.IndexHint{
IndexNames: hint.Indexes,
HintType: ast.HintUse,
HintScope: ast.HintForScan,
},
})
case HintIgnoreIndex:
dbName := hint.Tables[0].DBName
if dbName.L == "" {
dbName = model.NewCIStr(b.ctx.GetSessionVars().CurrentDB)
}
indexHintList = append(indexHintList, indexHintInfo{
dbName: dbName,
tblName: hint.Tables[0].TableName,
partitions: hint.Tables[0].PartitionList,
indexHint: &ast.IndexHint{
IndexNames: hint.Indexes,
HintType: ast.HintIgnore,
HintScope: ast.HintForScan,
},
})
case HintForceIndex:
dbName := hint.Tables[0].DBName
if dbName.L == "" {
dbName = model.NewCIStr(b.ctx.GetSessionVars().CurrentDB)
}
indexHintList = append(indexHintList, indexHintInfo{
dbName: dbName,
tblName: hint.Tables[0].TableName,
partitions: hint.Tables[0].PartitionList,
indexHint: &ast.IndexHint{
IndexNames: hint.Indexes,
HintType: ast.HintForce,
HintScope: ast.HintForScan,
},
})
case HintReadFromStorage:
switch hint.HintData.(model.CIStr).L {
case HintTiFlash:
tiflashTables = append(tiflashTables, tableNames2HintTableInfo(b.ctx, hint.HintName.L, hint.Tables, b.hintProcessor, currentLevel)...)
case HintTiKV:
tikvTables = append(tikvTables, tableNames2HintTableInfo(b.ctx, hint.HintName.L, hint.Tables, b.hintProcessor, currentLevel)...)
}
case HintIndexMerge:
dbName := hint.Tables[0].DBName
if dbName.L == "" {
dbName = model.NewCIStr(b.ctx.GetSessionVars().CurrentDB)
}
indexMergeHintList = append(indexMergeHintList, indexHintInfo{
dbName: dbName,
tblName: hint.Tables[0].TableName,
partitions: hint.Tables[0].PartitionList,
indexHint: &ast.IndexHint{
IndexNames: hint.Indexes,
HintType: ast.HintUse,
HintScope: ast.HintForScan,
},
})
case HintTimeRange:
timeRangeHint = hint.HintData.(ast.HintTimeRange)
case HintLimitToCop:
limitHints.preferLimitToCop = true
case HintMerge:
if hint.Tables != nil {
b.ctx.GetSessionVars().StmtCtx.AppendWarning(ErrInternal.GenWithStack("The MERGE hint is not used correctly, maybe it inputs a table name."))
continue
}
MergeHints.preferMerge = true
case HintLeading:
if leadingHintCnt == 0 {
leadingJoinOrder = append(leadingJoinOrder, tableNames2HintTableInfo(b.ctx, hint.HintName.L, hint.Tables, b.hintProcessor, currentLevel)...)
}
leadingHintCnt++
case HintSemiJoinRewrite:
if !b.checkSemiJoinHint {
b.ctx.GetSessionVars().StmtCtx.AppendWarning(ErrInternal.GenWithStack("The SEMI_JOIN_REWRITE hint is not used correctly, maybe it's not in a subquery or the subquery is not EXISTS clause."))
continue
}
b.hasValidSemiJoinHint = true
default:
// ignore hints that not implemented
}
}
if leadingHintCnt > 1 || (leadingHintCnt > 0 && b.ctx.GetSessionVars().StmtCtx.StraightJoinOrder) {
// If there are more leading hints or the straight_join hint existes, all leading hints will be invalid.
leadingJoinOrder = leadingJoinOrder[:0]
if leadingHintCnt > 1 {
b.ctx.GetSessionVars().StmtCtx.AppendWarning(ErrInternal.GenWithStack("We can only use one leading hint at most, when multiple leading hints are used, all leading hints will be invalid"))
} else if b.ctx.GetSessionVars().StmtCtx.StraightJoinOrder {
b.ctx.GetSessionVars().StmtCtx.AppendWarning(ErrInternal.GenWithStack("We can only use the straight_join hint, when we use the leading hint and straight_join hint at the same time, all leading hints will be invalid"))
}
}
b.tableHintInfo = append(b.tableHintInfo, tableHintInfo{
sortMergeJoinTables: sortMergeTables,
broadcastJoinTables: BCTables,
indexNestedLoopJoinTables: indexNestedLoopJoinTables{INLJTables, INLHJTables, INLMJTables},
hashJoinTables: hashJoinTables,
indexHintList: indexHintList,
tiflashTables: tiflashTables,
tikvTables: tikvTables,
aggHints: aggHints,
indexMergeHintList: indexMergeHintList,
timeRangeHint: timeRangeHint,
limitHints: limitHints,
MergeHints: MergeHints,
leadingJoinOrder: leadingJoinOrder,
hjBuildTables: hjBuildTables,
hjProbeTables: hjProbeTables,
})
}
func (b *PlanBuilder) popVisitInfo() {
if len(b.visitInfo) == 0 {
return
}
b.visitInfo = b.visitInfo[:len(b.visitInfo)-1]
}
func (b *PlanBuilder) popTableHints() {
hintInfo := b.tableHintInfo[len(b.tableHintInfo)-1]
b.appendUnmatchedIndexHintWarning(hintInfo.indexHintList, false)
b.appendUnmatchedIndexHintWarning(hintInfo.indexMergeHintList, true)
b.appendUnmatchedJoinHintWarning(HintINLJ, TiDBIndexNestedLoopJoin, hintInfo.indexNestedLoopJoinTables.inljTables)
b.appendUnmatchedJoinHintWarning(HintINLHJ, "", hintInfo.indexNestedLoopJoinTables.inlhjTables)
b.appendUnmatchedJoinHintWarning(HintINLMJ, "", hintInfo.indexNestedLoopJoinTables.inlmjTables)
b.appendUnmatchedJoinHintWarning(HintSMJ, TiDBMergeJoin, hintInfo.sortMergeJoinTables)
b.appendUnmatchedJoinHintWarning(HintBCJ, TiDBBroadCastJoin, hintInfo.broadcastJoinTables)
b.appendUnmatchedJoinHintWarning(HintHJ, TiDBHashJoin, hintInfo.hashJoinTables)
b.appendUnmatchedJoinHintWarning(HintHashJoinBuild, "", hintInfo.hjBuildTables)
b.appendUnmatchedJoinHintWarning(HintHashJoinProbe, "", hintInfo.hjProbeTables)
b.appendUnmatchedJoinHintWarning(HintLeading, "", hintInfo.leadingJoinOrder)
b.appendUnmatchedStorageHintWarning(hintInfo.tiflashTables, hintInfo.tikvTables)
b.tableHintInfo = b.tableHintInfo[:len(b.tableHintInfo)-1]
}
func (b *PlanBuilder) appendUnmatchedIndexHintWarning(indexHints []indexHintInfo, usedForIndexMerge bool) {
for _, hint := range indexHints {
if !hint.matched {
var hintTypeString string
if usedForIndexMerge {
hintTypeString = "use_index_merge"
} else {
hintTypeString = hint.hintTypeString()
}
errMsg := fmt.Sprintf("%s(%s) is inapplicable, check whether the table(%s.%s) exists",
hintTypeString,
hint.indexString(),
hint.dbName,
hint.tblName,
)
b.ctx.GetSessionVars().StmtCtx.AppendWarning(ErrInternal.GenWithStack(errMsg))
}
}
}
func (b *PlanBuilder) appendUnmatchedJoinHintWarning(joinType string, joinTypeAlias string, hintTables []hintTableInfo) {
unMatchedTables := extractUnmatchedTables(hintTables)
if len(unMatchedTables) == 0 {
return
}
if len(joinTypeAlias) != 0 {
joinTypeAlias = fmt.Sprintf(" or %s", restore2JoinHint(joinTypeAlias, hintTables))
}
errMsg := fmt.Sprintf("There are no matching table names for (%s) in optimizer hint %s%s. Maybe you can use the table alias name",
strings.Join(unMatchedTables, ", "), restore2JoinHint(joinType, hintTables), joinTypeAlias)
b.ctx.GetSessionVars().StmtCtx.AppendWarning(ErrInternal.GenWithStack(errMsg))
}
func (b *PlanBuilder) appendUnmatchedStorageHintWarning(tiflashTables, tikvTables []hintTableInfo) {
unMatchedTiFlashTables := extractUnmatchedTables(tiflashTables)
unMatchedTiKVTables := extractUnmatchedTables(tikvTables)
if len(unMatchedTiFlashTables)+len(unMatchedTiKVTables) == 0 {
return
}
errMsg := fmt.Sprintf("There are no matching table names for (%s) in optimizer hint %s. Maybe you can use the table alias name",
strings.Join(append(unMatchedTiFlashTables, unMatchedTiKVTables...), ", "),
restore2StorageHint(tiflashTables, tikvTables))
b.ctx.GetSessionVars().StmtCtx.AppendWarning(ErrInternal.GenWithStack(errMsg))
}
// TableHints returns the *tableHintInfo of PlanBuilder.
func (b *PlanBuilder) TableHints() *tableHintInfo {
if len(b.tableHintInfo) == 0 {
return nil
}
return &(b.tableHintInfo[len(b.tableHintInfo)-1])
}
func (b *PlanBuilder) buildSelect(ctx context.Context, sel *ast.SelectStmt) (p LogicalPlan, err error) {
b.pushSelectOffset(sel.QueryBlockOffset)
b.pushTableHints(sel.TableHints, sel.QueryBlockOffset)
defer func() {
b.popSelectOffset()
// table hints are only visible in the current SELECT statement.
b.popTableHints()
}()
if b.buildingRecursivePartForCTE {
if sel.Distinct || sel.OrderBy != nil || sel.Limit != nil {
return nil, ErrNotSupportedYet.GenWithStackByArgs("ORDER BY / LIMIT / SELECT DISTINCT in recursive query block of Common Table Expression")
}
if sel.GroupBy != nil {
return nil, ErrCTERecursiveForbidsAggregation.FastGenByArgs(b.genCTETableNameForError())
}
}
noopFuncsMode := b.ctx.GetSessionVars().NoopFuncsMode
if sel.SelectStmtOpts != nil {
if sel.SelectStmtOpts.CalcFoundRows && noopFuncsMode != variable.OnInt {
err = expression.ErrFunctionsNoopImpl.GenWithStackByArgs("SQL_CALC_FOUND_ROWS")
if noopFuncsMode == variable.OffInt {
return nil, err
}
// NoopFuncsMode is Warn, append an error
b.ctx.GetSessionVars().StmtCtx.AppendWarning(err)
}
origin := b.inStraightJoin
b.inStraightJoin = sel.SelectStmtOpts.StraightJoin
defer func() { b.inStraightJoin = origin }()
}
var (
aggFuncs []*ast.AggregateFuncExpr
havingMap, orderMap, totalMap map[*ast.AggregateFuncExpr]int
windowAggMap map[*ast.AggregateFuncExpr]int
correlatedAggMap map[*ast.AggregateFuncExpr]int
gbyCols []expression.Expression
projExprs []expression.Expression
)
// set for update read to true before building result set node
if isForUpdateReadSelectLock(sel.LockInfo) {
b.isForUpdateRead = true
}
// If the session variable "tidb_opt_force_inline_cte" is true, all of CTEs will be inlined.
// Otherwise, whether CTEs are inlined depends on whether the merge() hint is declared.
if b.ctx.GetSessionVars().EnableForceInlineCTE() {
if b.buildingCTE && b.isCTE {
b.outerCTEs[len(b.outerCTEs)-1].isInline = true
}
} else if hints := b.TableHints(); hints != nil && hints.MergeHints.preferMerge {
// Verify Merge hints in the current query,
// we will update parameters for those that meet the rules, and warn those that do not.
// If the current query uses Merge Hint and the query is a CTE,
// we update the HINT information for the current query.
// If the current query is not a CTE query (it may be a subquery within a CTE query
// or an external non-CTE query), we will give a warning.
// In particular, recursive CTE have separate warnings, so they are no longer called.
if b.buildingCTE {
if b.isCTE {
b.outerCTEs[len(b.outerCTEs)-1].isInline = hints.MergeHints.preferMerge
} else if !b.buildingRecursivePartForCTE {
//If there has subquery which is not CTE and using `MERGE()` hint, we will show this warning;
b.ctx.GetSessionVars().StmtCtx.AppendWarning(
ErrInternal.GenWithStack("Hint merge() is inapplicable. " +
"Please check whether the hint is used in the right place, " +
"you should use this hint inside the CTE."))
}
} else if !b.buildingCTE && !b.isCTE {
b.ctx.GetSessionVars().StmtCtx.AppendWarning(
ErrInternal.GenWithStack("Hint merge() is inapplicable. " +
"Please check whether the hint is used in the right place, " +
"you should use this hint inside the CTE."))
}
}
if sel.With != nil {
l := len(b.outerCTEs)
defer func() {
b.outerCTEs = b.outerCTEs[:l]
}()
err = b.buildWith(ctx, sel.With)
if err != nil {
return nil, err
}
}
p, err = b.buildTableRefs(ctx, sel.From)
if err != nil {
return nil, err
}
originalFields := sel.Fields.Fields
sel.Fields.Fields, err = b.unfoldWildStar(p, sel.Fields.Fields)
if err != nil {
return nil, err
}
if b.capFlag&canExpandAST != 0 {
// To be compatible with MySQL, we add alias name for each select field when creating view.
sel.Fields.Fields, err = b.addAliasName(ctx, sel, p)
if err != nil {
return nil, err
}
originalFields = sel.Fields.Fields
}
if sel.GroupBy != nil {
p, gbyCols, err = b.resolveGbyExprs(ctx, p, sel.GroupBy, sel.Fields.Fields)
if err != nil {
return nil, err
}
}
if b.ctx.GetSessionVars().SQLMode.HasOnlyFullGroupBy() && sel.From != nil && !b.ctx.GetSessionVars().OptimizerEnableNewOnlyFullGroupByCheck {
err = b.checkOnlyFullGroupBy(p, sel)
if err != nil {
return nil, err
}
}
hasWindowFuncField := b.detectSelectWindow(sel)
// Some SQL statements define WINDOW but do not use them. But we also need to check the window specification list.
// For example: select id from t group by id WINDOW w AS (ORDER BY uids DESC) ORDER BY id;
// We don't use the WINDOW w, but if the 'uids' column is not in the table t, we still need to report an error.
if hasWindowFuncField || sel.WindowSpecs != nil {
if b.buildingRecursivePartForCTE {
return nil, ErrCTERecursiveForbidsAggregation.FastGenByArgs(b.genCTETableNameForError())
}
windowAggMap, err = b.resolveWindowFunction(sel, p)
if err != nil {
return nil, err
}
}
// We must resolve having and order by clause before build projection,
// because when the query is "select a+1 as b from t having sum(b) < 0", we must replace sum(b) to sum(a+1),
// which only can be done before building projection and extracting Agg functions.
havingMap, orderMap, err = b.resolveHavingAndOrderBy(ctx, sel, p)
if err != nil {
return nil, err
}
// We have to resolve correlated aggregate inside sub-queries before building aggregation and building projection,
// for instance, count(a) inside the sub-query of "select (select count(a)) from t" should be evaluated within
// the context of the outer query. So we have to extract such aggregates from sub-queries and put them into
// SELECT field list.
correlatedAggMap, err = b.resolveCorrelatedAggregates(ctx, sel, p)
if err != nil {
return nil, err
}
// b.allNames will be used in evalDefaultExpr(). Default function is special because it needs to find the
// corresponding column name, but does not need the value in the column.
// For example, select a from t order by default(b), the column b will not be in select fields. Also because
// buildSort is after buildProjection, so we need get OutputNames before BuildProjection and store in allNames.
// Otherwise, we will get select fields instead of all OutputNames, so that we can't find the column b in the
// above example.
b.allNames = append(b.allNames, p.OutputNames())
defer func() { b.allNames = b.allNames[:len(b.allNames)-1] }()
if sel.Where != nil {
p, err = b.buildSelection(ctx, p, sel.Where, nil)
if err != nil {
return nil, err
}
}
l := sel.LockInfo
if l != nil && l.LockType != ast.SelectLockNone {
if l.LockType == ast.SelectLockForShare && noopFuncsMode != variable.OnInt {
err = expression.ErrFunctionsNoopImpl.GenWithStackByArgs("LOCK IN SHARE MODE")
if noopFuncsMode == variable.OffInt {
return nil, err
}
// NoopFuncsMode is Warn, append an error
b.ctx.GetSessionVars().StmtCtx.AppendWarning(err)
}
for _, tName := range l.Tables {
b.ctx.GetSessionVars().StmtCtx.LockTableIDs[tName.TableInfo.ID] = struct{}{}
}
p, err = b.buildSelectLock(p, l)
if err != nil {
return nil, err
}
}
b.handleHelper.popMap()
b.handleHelper.pushMap(nil)
hasAgg := b.detectSelectAgg(sel)
needBuildAgg := hasAgg
if hasAgg {
if b.buildingRecursivePartForCTE {
return nil, ErrCTERecursiveForbidsAggregation.GenWithStackByArgs(b.genCTETableNameForError())
}
aggFuncs, totalMap = b.extractAggFuncsInSelectFields(sel.Fields.Fields)
// len(aggFuncs) == 0 and sel.GroupBy == nil indicates that all the aggregate functions inside the SELECT fields
// are actually correlated aggregates from the outer query, which have already been built in the outer query.
// The only thing we need to do is to find them from b.correlatedAggMap in buildProjection.
if len(aggFuncs) == 0 && sel.GroupBy == nil {
needBuildAgg = false
}
}
if needBuildAgg {
var aggIndexMap map[int]int
p, aggIndexMap, err = b.buildAggregation(ctx, p, aggFuncs, gbyCols, correlatedAggMap)
if err != nil {
return nil, err
}
for agg, idx := range totalMap {
totalMap[agg] = aggIndexMap[idx]
}
}
var oldLen int
// According to https://dev.mysql.com/doc/refman/8.0/en/window-functions-usage.html,
// we can only process window functions after having clause, so `considerWindow` is false now.
p, projExprs, oldLen, err = b.buildProjection(ctx, p, sel.Fields.Fields, totalMap, nil, false, sel.OrderBy != nil)
if err != nil {
return nil, err
}
if sel.Having != nil {
b.curClause = havingClause
p, err = b.buildSelection(ctx, p, sel.Having.Expr, havingMap)
if err != nil {
return nil, err
}
}
b.windowSpecs, err = buildWindowSpecs(sel.WindowSpecs)
if err != nil {
return nil, err
}
var windowMapper map[*ast.WindowFuncExpr]int
if hasWindowFuncField || sel.WindowSpecs != nil {
windowFuncs := extractWindowFuncs(sel.Fields.Fields)
// we need to check the func args first before we check the window spec
err := b.checkWindowFuncArgs(ctx, p, windowFuncs, windowAggMap)
if err != nil {
return nil, err
}
groupedFuncs, orderedSpec, err := b.groupWindowFuncs(windowFuncs)
if err != nil {
return nil, err
}
p, windowMapper, err = b.buildWindowFunctions(ctx, p, groupedFuncs, orderedSpec, windowAggMap)
if err != nil {
return nil, err
}
// `hasWindowFuncField == false` means there's only unused named window specs without window functions.
// In such case plan `p` is not changed, so we don't have to build another projection.
if hasWindowFuncField {
// Now we build the window function fields.
p, projExprs, oldLen, err = b.buildProjection(ctx, p, sel.Fields.Fields, windowAggMap, windowMapper, true, false)
if err != nil {
return nil, err
}
}
}
if sel.Distinct {
p, err = b.buildDistinct(p, oldLen)
if err != nil {
return nil, err
}
}
if sel.OrderBy != nil {
// We need to keep the ORDER BY clause for the following cases:
// 1. The select is top level query, order should be honored
// 2. The query has LIMIT clause
// 3. The control flag requires keeping ORDER BY explicitly
if len(b.selectOffset) == 1 || sel.Limit != nil || !b.ctx.GetSessionVars().RemoveOrderbyInSubquery {
if b.ctx.GetSessionVars().SQLMode.HasOnlyFullGroupBy() {
p, err = b.buildSortWithCheck(ctx, p, sel.OrderBy.Items, orderMap, windowMapper, projExprs, oldLen, sel.Distinct)
} else {
p, err = b.buildSort(ctx, p, sel.OrderBy.Items, orderMap, windowMapper)
}
if err != nil {
return nil, err
}
}
}
if sel.Limit != nil {
p, err = b.buildLimit(p, sel.Limit)
if err != nil {
return nil, err
}
}
sel.Fields.Fields = originalFields
if oldLen != p.Schema().Len() {
proj := LogicalProjection{Exprs: expression.Column2Exprs(p.Schema().Columns[:oldLen])}.Init(b.ctx, b.getSelectOffset())
proj.SetChildren(p)
schema := expression.NewSchema(p.Schema().Clone().Columns[:oldLen]...)
for _, col := range schema.Columns {
col.UniqueID = b.ctx.GetSessionVars().AllocPlanColumnID()
}
proj.names = p.OutputNames()[:oldLen]
proj.SetSchema(schema)
return proj, nil
}
return p, nil
}
func (b *PlanBuilder) buildTableDual() *LogicalTableDual {
b.handleHelper.pushMap(nil)
return LogicalTableDual{RowCount: 1}.Init(b.ctx, b.getSelectOffset())
}
func (ds *DataSource) newExtraHandleSchemaCol() *expression.Column {
tp := types.NewFieldType(mysql.TypeLonglong)
tp.SetFlag(mysql.NotNullFlag | mysql.PriKeyFlag)
return &expression.Column{
RetType: tp,
UniqueID: ds.ctx.GetSessionVars().AllocPlanColumnID(),
ID: model.ExtraHandleID,
OrigName: fmt.Sprintf("%v.%v.%v", ds.DBName, ds.tableInfo.Name, model.ExtraHandleName),
}
}
// AddExtraPhysTblIDColumn for partition table.
// 'select ... for update' on a partition table need to know the partition ID
// to construct the lock key, so this column is added to the chunk row.
// Also needed for checking against the sessions transaction buffer
func (ds *DataSource) AddExtraPhysTblIDColumn() *expression.Column {
// Avoid adding multiple times (should never happen!)
cols := ds.TblCols
for i := len(cols) - 1; i >= 0; i-- {
if cols[i].ID == model.ExtraPhysTblID {
return cols[i]
}
}
pidCol := &expression.Column{
RetType: types.NewFieldType(mysql.TypeLonglong),
UniqueID: ds.ctx.GetSessionVars().AllocPlanColumnID(),
ID: model.ExtraPhysTblID,
OrigName: fmt.Sprintf("%v.%v.%v", ds.DBName, ds.tableInfo.Name, model.ExtraPhysTblIdName),
}
ds.Columns = append(ds.Columns, model.NewExtraPhysTblIDColInfo())
schema := ds.Schema()
schema.Append(pidCol)
ds.names = append(ds.names, &types.FieldName{
DBName: ds.DBName,
TblName: ds.TableInfo().Name,
ColName: model.ExtraPhysTblIdName,
OrigColName: model.ExtraPhysTblIdName,
})
ds.TblCols = append(ds.TblCols, pidCol)
return pidCol
}
var (
pseudoEstimationNotAvailable = metrics.PseudoEstimation.WithLabelValues("nodata")
pseudoEstimationOutdate = metrics.PseudoEstimation.WithLabelValues("outdate")
)
// getStatsTable gets statistics information for a table specified by "tableID".
// A pseudo statistics table is returned in any of the following scenario:
// 1. tidb-server started and statistics handle has not been initialized.
// 2. table row count from statistics is zero.
// 3. statistics is outdated.
func getStatsTable(ctx sessionctx.Context, tblInfo *model.TableInfo, pid int64) *statistics.Table {
statsHandle := domain.GetDomain(ctx).StatsHandle()
// 1. tidb-server started and statistics handle has not been initialized.
if statsHandle == nil {
return statistics.PseudoTable(tblInfo)
}
var statsTbl *statistics.Table
if pid == tblInfo.ID || ctx.GetSessionVars().StmtCtx.UseDynamicPartitionPrune() {
statsTbl = statsHandle.GetTableStats(tblInfo, handle.WithTableStatsByQuery())
} else {
statsTbl = statsHandle.GetPartitionStats(tblInfo, pid, handle.WithTableStatsByQuery())
}
// 2. table row count from statistics is zero.
if statsTbl.Count == 0 {
pseudoEstimationNotAvailable.Inc()
return statistics.PseudoTable(tblInfo)
}
// 3. statistics is uninitialized or outdated.
pseudoStatsForUninitialized := !statsTbl.IsInitialized()
pseudoStatsForOutdated := ctx.GetSessionVars().GetEnablePseudoForOutdatedStats() && statsTbl.IsOutdated()
if pseudoStatsForUninitialized || pseudoStatsForOutdated {
tbl := *statsTbl
tbl.Pseudo = true
statsTbl = &tbl
if pseudoStatsForUninitialized {
pseudoEstimationNotAvailable.Inc()
} else {
pseudoEstimationOutdate.Inc()
}
}
return statsTbl
}
func (b *PlanBuilder) tryBuildCTE(ctx context.Context, tn *ast.TableName, asName *model.CIStr) (LogicalPlan, error) {
for i := len(b.outerCTEs) - 1; i >= 0; i-- {
cte := b.outerCTEs[i]
if cte.def.Name.L == tn.Name.L {
if cte.isBuilding {
if cte.nonRecursive {
// Can't see this CTE, try outer definition.
continue
}
// Building the recursive part.
cte.useRecursive = true
if cte.seedLP == nil {
return nil, ErrCTERecursiveRequiresNonRecursiveFirst.FastGenByArgs(tn.Name.String())
}
if cte.enterSubquery || cte.recursiveRef {
return nil, ErrInvalidRequiresSingleReference.FastGenByArgs(tn.Name.String())
}
cte.recursiveRef = true
p := LogicalCTETable{name: cte.def.Name.String(), idForStorage: cte.storageID, seedStat: cte.seedStat, seedSchema: cte.seedLP.Schema()}.Init(b.ctx, b.getSelectOffset())
p.SetSchema(getResultCTESchema(cte.seedLP.Schema(), b.ctx.GetSessionVars()))
p.SetOutputNames(cte.seedLP.OutputNames())
return p, nil
}
b.handleHelper.pushMap(nil)
hasLimit := false
limitBeg := uint64(0)
limitEnd := uint64(0)
if cte.limitLP != nil {
hasLimit = true
switch x := cte.limitLP.(type) {
case *LogicalLimit:
limitBeg = x.Offset
limitEnd = x.Offset + x.Count
case *LogicalTableDual:
// Beg and End will both be 0.
default:
return nil, errors.Errorf("invalid type for limit plan: %v", cte.limitLP)
}
}
if cte.cteClass == nil {
cte.cteClass = &CTEClass{IsDistinct: cte.isDistinct, seedPartLogicalPlan: cte.seedLP,
recursivePartLogicalPlan: cte.recurLP, IDForStorage: cte.storageID,
optFlag: cte.optFlag, HasLimit: hasLimit, LimitBeg: limitBeg,
LimitEnd: limitEnd, pushDownPredicates: make([]expression.Expression, 0), ColumnMap: make(map[string]*expression.Column)}
}
var p LogicalPlan
lp := LogicalCTE{cteAsName: tn.Name, cte: cte.cteClass, seedStat: cte.seedStat, isOuterMostCTE: !b.buildingCTE}.Init(b.ctx, b.getSelectOffset())
prevSchema := cte.seedLP.Schema().Clone()
lp.SetSchema(getResultCTESchema(cte.seedLP.Schema(), b.ctx.GetSessionVars()))
if cte.recurLP != nil && cte.isInline {
b.ctx.GetSessionVars().StmtCtx.AppendWarning(
ErrInternal.GenWithStack("Recursive CTE can not be inlined."))
}
if cte.recurLP == nil && cte.isInline {
saveCte := make([]*cteInfo, len(b.outerCTEs[i:]))
copy(saveCte, b.outerCTEs[i:])
b.outerCTEs = b.outerCTEs[:i]
o := b.buildingCTE
b.buildingCTE = false
//nolint:all_revive,revive
defer func() {
b.outerCTEs = append(b.outerCTEs, saveCte...)
b.buildingCTE = o
}()
return b.buildDataSourceFromCTEMerge(ctx, cte.def)
}
for i, col := range lp.schema.Columns {
lp.cte.ColumnMap[string(col.HashCode(nil))] = prevSchema.Columns[i]
}
p = lp
p.SetOutputNames(cte.seedLP.OutputNames())
if len(asName.String()) > 0 {
lp.cteAsName = *asName
var on types.NameSlice
for _, name := range p.OutputNames() {
cpOn := *name
cpOn.TblName = *asName
on = append(on, &cpOn)
}
p.SetOutputNames(on)
}
return p, nil
}
}
return nil, nil
}
func (b *PlanBuilder) buildDataSourceFromCTEMerge(ctx context.Context, cte *ast.CommonTableExpression) (LogicalPlan, error) {
p, err := b.buildResultSetNode(ctx, cte.Query.Query, true)
if err != nil {
return nil, err
}
outPutNames := p.OutputNames()
for _, name := range outPutNames {
name.TblName = cte.Name
name.DBName = model.NewCIStr(b.ctx.GetSessionVars().CurrentDB)
}
if len(cte.ColNameList) > 0 {
if len(cte.ColNameList) != len(p.OutputNames()) {
return nil, errors.New("CTE columns length is not consistent")
}
for i, n := range cte.ColNameList {
outPutNames[i].ColName = n
}
}
p.SetOutputNames(outPutNames)
return p, nil
}
func (b *PlanBuilder) buildDataSource(ctx context.Context, tn *ast.TableName, asName *model.CIStr) (LogicalPlan, error) {
dbName := tn.Schema
sessionVars := b.ctx.GetSessionVars()
if dbName.L == "" {
// Try CTE.
p, err := b.tryBuildCTE(ctx, tn, asName)
if err != nil || p != nil {
return p, err
}
dbName = model.NewCIStr(sessionVars.CurrentDB)
}
is := b.is
if len(b.buildingViewStack) > 0 {
// For tables in view, always ignore local temporary table, considering the below case:
// If a user created a normal table `t1` and a view `v1` referring `t1`, and then a local temporary table with a same name `t1` is created.
// At this time, executing 'select * from v1' should still return all records from normal table `t1` instead of temporary table `t1`.
is = temptable.DetachLocalTemporaryTableInfoSchema(is)
}
tbl, err := is.TableByName(dbName, tn.Name)
if err != nil {
return nil, err
}
tbl, err = tryLockMDLAndUpdateSchemaIfNecessary(b.ctx, dbName, tbl, b.is)
if err != nil {
return nil, err
}
tableInfo := tbl.Meta()
if b.isCreateView && tableInfo.TempTableType == model.TempTableLocal {
return nil, ErrViewSelectTemporaryTable.GenWithStackByArgs(tn.Name)
}
var authErr error
if sessionVars.User != nil {
authErr = ErrTableaccessDenied.FastGenByArgs("SELECT", sessionVars.User.AuthUsername, sessionVars.User.AuthHostname, tableInfo.Name.L)
}
b.visitInfo = appendVisitInfo(b.visitInfo, mysql.SelectPriv, dbName.L, tableInfo.Name.L, "", authErr)
if tbl.Type().IsVirtualTable() {
if tn.TableSample != nil {
return nil, expression.ErrInvalidTableSample.GenWithStackByArgs("Unsupported TABLESAMPLE in virtual tables")
}
return b.buildMemTable(ctx, dbName, tableInfo)
}
tblName := *asName
if tblName.L == "" {
tblName = tn.Name
}
possiblePaths, err := getPossibleAccessPaths(b.ctx, b.TableHints(), tn.IndexHints, tbl, dbName, tblName, b.isForUpdateRead, b.is.SchemaMetaVersion())
if err != nil {
return nil, err
}
if tableInfo.IsView() {
if tn.TableSample != nil {
return nil, expression.ErrInvalidTableSample.GenWithStackByArgs("Unsupported TABLESAMPLE in views")
}
return b.BuildDataSourceFromView(ctx, dbName, tableInfo)
}
if tableInfo.IsSequence() {
if tn.TableSample != nil {
return nil, expression.ErrInvalidTableSample.GenWithStackByArgs("Unsupported TABLESAMPLE in sequences")
}
// When the source is a Sequence, we convert it to a TableDual, as what most databases do.
return b.buildTableDual(), nil
}
if tableInfo.GetPartitionInfo() != nil {
h := domain.GetDomain(b.ctx).StatsHandle()
tblStats := h.GetTableStats(tableInfo)
isDynamicEnabled := b.ctx.GetSessionVars().IsDynamicPartitionPruneEnabled()
globalStatsReady := tblStats.IsInitialized()
// If dynamic partition prune isn't enabled or global stats is not ready, we won't enable dynamic prune mode in query
usePartitionProcessor := !isDynamicEnabled || !globalStatsReady
failpoint.Inject("forceDynamicPrune", func(val failpoint.Value) {
if val.(bool) {
if isDynamicEnabled {
usePartitionProcessor = false
}
}
})
if usePartitionProcessor {
b.optFlag = b.optFlag | flagPartitionProcessor
b.ctx.GetSessionVars().StmtCtx.UseDynamicPruneMode = false
if isDynamicEnabled {
b.ctx.GetSessionVars().StmtCtx.AppendWarning(
fmt.Errorf("disable dynamic pruning due to %s has no global stats", tableInfo.Name.String()))
}
}
pt := tbl.(table.PartitionedTable)
// check partition by name.
if len(tn.PartitionNames) > 0 {
pids := make(map[int64]struct{}, len(tn.PartitionNames))
for _, name := range tn.PartitionNames {
pid, err := tables.FindPartitionByName(tableInfo, name.L)
if err != nil {
return nil, err
}
pids[pid] = struct{}{}
}
pt = tables.NewPartitionTableWithGivenSets(pt, pids)
}
b.partitionedTable = append(b.partitionedTable, pt)
} else if len(tn.PartitionNames) != 0 {
return nil, ErrPartitionClauseOnNonpartitioned
}
// Skip storage engine check for CreateView.
if b.capFlag&canExpandAST == 0 {
possiblePaths, err = filterPathByIsolationRead(b.ctx, possiblePaths, tblName, dbName)
if err != nil {
return nil, err
}
}
// Try to substitute generate column only if there is an index on generate column.
for _, index := range tableInfo.Indices {
if index.State != model.StatePublic {
continue
}
for _, indexCol := range index.Columns {
colInfo := tbl.Cols()[indexCol.Offset]
if colInfo.IsGenerated() && !colInfo.GeneratedStored {
b.optFlag |= flagGcSubstitute
break
}
}
}
var columns []*table.Column
if b.inUpdateStmt {
// create table t(a int, b int).
// Imagine that, There are 2 TiDB instances in the cluster, name A, B. We add a column `c` to table t in the TiDB cluster.
// One of the TiDB, A, the column type in its infoschema is changed to public. And in the other TiDB, the column type is
// still StateWriteReorganization.
// TiDB A: insert into t values(1, 2, 3);
// TiDB B: update t set a = 2 where b = 2;
// If we use tbl.Cols() here, the update statement, will ignore the col `c`, and the data `3` will lost.
columns = tbl.WritableCols()
} else if b.inDeleteStmt {
// DeletableCols returns all columns of the table in deletable states.
columns = tbl.DeletableCols()
} else {
columns = tbl.Cols()
}
// extract the IndexMergeHint
var indexMergeHints []indexHintInfo
if hints := b.TableHints(); hints != nil {
for i, hint := range hints.indexMergeHintList {
if hint.tblName.L == tblName.L && hint.dbName.L == dbName.L {
hints.indexMergeHintList[i].matched = true
// check whether the index names in IndexMergeHint are valid.
invalidIdxNames := make([]string, 0, len(hint.indexHint.IndexNames))
for _, idxName := range hint.indexHint.IndexNames {
hasIdxName := false
for _, path := range possiblePaths {
if path.IsTablePath() {
if idxName.L == "primary" {
hasIdxName = true
break
}
continue
}
if idxName.L == path.Index.Name.L {
hasIdxName = true
break
}
}
if !hasIdxName {
invalidIdxNames = append(invalidIdxNames, idxName.String())
}
}
if len(invalidIdxNames) == 0 {
indexMergeHints = append(indexMergeHints, hint)
} else {
// Append warning if there are invalid index names.
errMsg := fmt.Sprintf("use_index_merge(%s) is inapplicable, check whether the indexes (%s) "+
"exist, or the indexes are conflicted with use_index/ignore_index/force_index hints.",
hint.indexString(), strings.Join(invalidIdxNames, ", "))
b.ctx.GetSessionVars().StmtCtx.AppendWarning(ErrInternal.GenWithStack(errMsg))
}
}
}
}
ds := DataSource{
DBName: dbName,
TableAsName: asName,
table: tbl,
tableInfo: tableInfo,
physicalTableID: tableInfo.ID,
astIndexHints: tn.IndexHints,
IndexHints: b.TableHints().indexHintList,
indexMergeHints: indexMergeHints,
possibleAccessPaths: possiblePaths,
Columns: make([]*model.ColumnInfo, 0, len(columns)),
partitionNames: tn.PartitionNames,
TblCols: make([]*expression.Column, 0, len(columns)),
preferPartitions: make(map[int][]model.CIStr),
is: b.is,
isForUpdateRead: b.isForUpdateRead,
}.Init(b.ctx, b.getSelectOffset())
var handleCols HandleCols
schema := expression.NewSchema(make([]*expression.Column, 0, len(columns))...)
names := make([]*types.FieldName, 0, len(columns))
for i, col := range columns {
ds.Columns = append(ds.Columns, col.ToInfo())
names = append(names, &types.FieldName{
DBName: dbName,
TblName: tableInfo.Name,
ColName: col.Name,
OrigTblName: tableInfo.Name,
OrigColName: col.Name,
// For update statement and delete statement, internal version should see the special middle state column, while user doesn't.
NotExplicitUsable: col.State != model.StatePublic,
})
newCol := &expression.Column{
UniqueID: sessionVars.AllocPlanColumnID(),
ID: col.ID,
RetType: col.FieldType.Clone(),
OrigName: names[i].String(),
IsHidden: col.Hidden,
}
if col.IsPKHandleColumn(tableInfo) {
handleCols = &IntHandleCols{col: newCol}
}
schema.Append(newCol)
ds.TblCols = append(ds.TblCols, newCol)
}
// We append an extra handle column to the schema when the handle
// column is not the primary key of "ds".
if handleCols == nil {
if tableInfo.IsCommonHandle {
primaryIdx := tables.FindPrimaryIndex(tableInfo)
handleCols = NewCommonHandleCols(b.ctx.GetSessionVars().StmtCtx, tableInfo, primaryIdx, ds.TblCols)
} else {
extraCol := ds.newExtraHandleSchemaCol()
handleCols = &IntHandleCols{col: extraCol}
ds.Columns = append(ds.Columns, model.NewExtraHandleColInfo())
schema.Append(extraCol)
names = append(names, &types.FieldName{
DBName: dbName,
TblName: tableInfo.Name,
ColName: model.ExtraHandleName,
OrigColName: model.ExtraHandleName,
})
ds.TblCols = append(ds.TblCols, extraCol)
}
}
ds.handleCols = handleCols
handleMap := make(map[int64][]HandleCols)
handleMap[tableInfo.ID] = []HandleCols{handleCols}
b.handleHelper.pushMap(handleMap)
ds.SetSchema(schema)
ds.names = names
ds.setPreferredStoreType(b.TableHints())
ds.SampleInfo = NewTableSampleInfo(tn.TableSample, schema.Clone(), b.partitionedTable)
b.isSampling = ds.SampleInfo != nil
for i, colExpr := range ds.Schema().Columns {
var expr expression.Expression
if i < len(columns) {
if columns[i].IsGenerated() && !columns[i].GeneratedStored {
var err error
expr, _, err = b.rewrite(ctx, columns[i].GeneratedExpr, ds, nil, true)
if err != nil {
return nil, err
}
colExpr.VirtualExpr = expr.Clone()
}
}
}
// Init commonHandleCols and commonHandleLens for data source.
if tableInfo.IsCommonHandle {
ds.commonHandleCols, ds.commonHandleLens = expression.IndexInfo2Cols(ds.Columns, ds.schema.Columns, tables.FindPrimaryIndex(tableInfo))
}
// Init FullIdxCols, FullIdxColLens for accessPaths.
for _, path := range ds.possibleAccessPaths {
if !path.IsIntHandlePath {
path.FullIdxCols, path.FullIdxColLens = expression.IndexInfo2Cols(ds.Columns, ds.schema.Columns, path.Index)
// check whether the path's index has a tidb_shard() prefix and the index column count
// more than 1. e.g. index(tidb_shard(a), a)
// set UkShardIndexPath only for unique secondary index
if !path.IsCommonHandlePath {
// tidb_shard expression must be first column of index
col := path.FullIdxCols[0]
if col != nil &&
expression.GcColumnExprIsTidbShard(col.VirtualExpr) &&
len(path.Index.Columns) > 1 &&
path.Index.Unique {
path.IsUkShardIndexPath = true
ds.containExprPrefixUk = true
}
}
}
}
var result LogicalPlan = ds
dirty := tableHasDirtyContent(b.ctx, tableInfo)
if dirty || tableInfo.TempTableType == model.TempTableLocal || tableInfo.TableCacheStatusType == model.TableCacheStatusEnable {
us := LogicalUnionScan{handleCols: handleCols}.Init(b.ctx, b.getSelectOffset())
us.SetChildren(ds)
if tableInfo.Partition != nil && b.optFlag&flagPartitionProcessor == 0 {
// Adding ExtraPhysTblIDCol for UnionScan (transaction buffer handling)
// Not using old static prune mode
// Single TableReader for all partitions, needs the PhysTblID from storage
_ = ds.AddExtraPhysTblIDColumn()
}
result = us
}
// Adding ExtraPhysTblIDCol for SelectLock (SELECT FOR UPDATE) is done when building SelectLock
if sessionVars.StmtCtx.TblInfo2UnionScan == nil {
sessionVars.StmtCtx.TblInfo2UnionScan = make(map[*model.TableInfo]bool)
}
sessionVars.StmtCtx.TblInfo2UnionScan[tableInfo] = dirty
return result, nil
}
// ExtractFD implements the LogicalPlan interface.
func (ds *DataSource) ExtractFD() *fd.FDSet {
// FD in datasource (leaf node) can be cached and reused.
// Once the all conditions are not equal to nil, built it again.
if ds.fdSet == nil || ds.allConds != nil {
fds := &fd.FDSet{HashCodeToUniqueID: make(map[string]int)}
allCols := fd.NewFastIntSet()
// should use the column's unique ID avoiding fdSet conflict.
for _, col := range ds.TblCols {
// todo: change it to int64
allCols.Insert(int(col.UniqueID))
}
// int pk doesn't store its index column in indexInfo.
if ds.tableInfo.PKIsHandle {
keyCols := fd.NewFastIntSet()
for _, col := range ds.TblCols {
if mysql.HasPriKeyFlag(col.RetType.GetFlag()) {
keyCols.Insert(int(col.UniqueID))
}
}
fds.AddStrictFunctionalDependency(keyCols, allCols)
fds.MakeNotNull(keyCols)
}
// we should check index valid while forUpdateRead, see detail in https://github.com/pingcap/tidb/pull/22152
var (
latestIndexes map[int64]*model.IndexInfo
changed bool
err error
)
check := ds.ctx.GetSessionVars().IsIsolation(ast.ReadCommitted) || ds.isForUpdateRead
check = check && ds.ctx.GetSessionVars().ConnectionID > 0
if check {
latestIndexes, changed, err = getLatestIndexInfo(ds.ctx, ds.table.Meta().ID, 0)
if err != nil {
ds.fdSet = fds
return fds
}
}
// other indices including common handle.
for _, idx := range ds.tableInfo.Indices {
keyCols := fd.NewFastIntSet()
allColIsNotNull := true
if ds.isForUpdateRead && changed {
latestIndex, ok := latestIndexes[idx.ID]
if !ok || latestIndex.State != model.StatePublic {
continue
}
}
if idx.State != model.StatePublic {
continue
}
for _, idxCol := range idx.Columns {
// Note: even the prefix column can also be the FD. For example:
// unique(char_column(10)), will also guarantee the prefix to be
// the unique which means the while column is unique too.
refCol := ds.tableInfo.Columns[idxCol.Offset]
if !mysql.HasNotNullFlag(refCol.GetFlag()) {
allColIsNotNull = false
}
keyCols.Insert(int(ds.TblCols[idxCol.Offset].UniqueID))
}
if idx.Primary {
fds.AddStrictFunctionalDependency(keyCols, allCols)
fds.MakeNotNull(keyCols)
} else if idx.Unique {
if allColIsNotNull {
fds.AddStrictFunctionalDependency(keyCols, allCols)
fds.MakeNotNull(keyCols)
} else {
// unique index:
// 1: normal value should be unique
// 2: null value can be multiple
// for this kind of lax to be strict, we need to make the determinant not-null.
fds.AddLaxFunctionalDependency(keyCols, allCols)
}
}
}
// handle the datasource conditions (maybe pushed down from upper layer OP)
if len(ds.allConds) != 0 {
// extract the not null attributes from selection conditions.
notnullColsUniqueIDs := extractNotNullFromConds(ds.allConds, ds)
// extract the constant cols from selection conditions.
constUniqueIDs := extractConstantCols(ds.allConds, ds.SCtx(), fds)
// extract equivalence cols.
equivUniqueIDs := extractEquivalenceCols(ds.allConds, ds.SCtx(), fds)
// apply conditions to FD.
fds.MakeNotNull(notnullColsUniqueIDs)
fds.AddConstants(constUniqueIDs)
for _, equiv := range equivUniqueIDs {
fds.AddEquivalence(equiv[0], equiv[1])
}
}
// build the dependency for generated columns.
// the generated column is sequentially dependent on the forward column.
// a int, b int as (a+1), c int as (b+1), here we can build the strict FD down:
// {a} -> {b}, {b} -> {c}, put the maintenance of the dependencies between generated columns to the FD graph.
notNullCols := fd.NewFastIntSet()
for _, col := range ds.TblCols {
if col.VirtualExpr != nil {
dependencies := fd.NewFastIntSet()
dependencies.Insert(int(col.UniqueID))
// dig out just for 1 level.
directBaseCol := expression.ExtractColumns(col.VirtualExpr)
determinant := fd.NewFastIntSet()
for _, col := range directBaseCol {
determinant.Insert(int(col.UniqueID))
}
fds.AddStrictFunctionalDependency(determinant, dependencies)
}
if mysql.HasNotNullFlag(col.RetType.GetFlag()) {
notNullCols.Insert(int(col.UniqueID))
}
}
fds.MakeNotNull(notNullCols)
ds.fdSet = fds
}
return ds.fdSet
}
func (b *PlanBuilder) timeRangeForSummaryTable() QueryTimeRange {
const defaultSummaryDuration = 30 * time.Minute
hints := b.TableHints()
// User doesn't use TIME_RANGE hint
if hints == nil || (hints.timeRangeHint.From == "" && hints.timeRangeHint.To == "") {
to := time.Now()
from := to.Add(-defaultSummaryDuration)
return QueryTimeRange{From: from, To: to}
}
// Parse time specified by user via TIM_RANGE hint
parse := func(s string) (time.Time, bool) {
t, err := time.ParseInLocation(MetricTableTimeFormat, s, time.Local)
if err != nil {
b.ctx.GetSessionVars().StmtCtx.AppendWarning(err)
}
return t, err == nil
}
from, fromValid := parse(hints.timeRangeHint.From)
to, toValid := parse(hints.timeRangeHint.To)
switch {
case !fromValid && !toValid:
to = time.Now()
from = to.Add(-defaultSummaryDuration)
case fromValid && !toValid:
to = from.Add(defaultSummaryDuration)
case !fromValid && toValid:
from = to.Add(-defaultSummaryDuration)
}
return QueryTimeRange{From: from, To: to}
}
func (b *PlanBuilder) buildMemTable(_ context.Context, dbName model.CIStr, tableInfo *model.TableInfo) (LogicalPlan, error) {
// We can use the `tableInfo.Columns` directly because the memory table has
// a stable schema and there is no online DDL on the memory table.
schema := expression.NewSchema(make([]*expression.Column, 0, len(tableInfo.Columns))...)
names := make([]*types.FieldName, 0, len(tableInfo.Columns))
var handleCols HandleCols
for _, col := range tableInfo.Columns {
names = append(names, &types.FieldName{
DBName: dbName,
TblName: tableInfo.Name,
ColName: col.Name,
OrigTblName: tableInfo.Name,
OrigColName: col.Name,
})
// NOTE: Rewrite the expression if memory table supports generated columns in the future
newCol := &expression.Column{
UniqueID: b.ctx.GetSessionVars().AllocPlanColumnID(),
ID: col.ID,
RetType: &col.FieldType,
}
if tableInfo.PKIsHandle && mysql.HasPriKeyFlag(col.GetFlag()) {
handleCols = &IntHandleCols{col: newCol}
}
schema.Append(newCol)
}
if handleCols != nil {
handleMap := make(map[int64][]HandleCols)
handleMap[tableInfo.ID] = []HandleCols{handleCols}
b.handleHelper.pushMap(handleMap)
} else {
b.handleHelper.pushMap(nil)
}
// NOTE: Add a `LogicalUnionScan` if we support update memory table in the future
p := LogicalMemTable{
DBName: dbName,
TableInfo: tableInfo,
Columns: make([]*model.ColumnInfo, len(tableInfo.Columns)),
}.Init(b.ctx, b.getSelectOffset())
p.SetSchema(schema)
p.names = names
copy(p.Columns, tableInfo.Columns)
// Some memory tables can receive some predicates
switch dbName.L {
case util2.MetricSchemaName.L:
p.Extractor = newMetricTableExtractor()
case util2.InformationSchemaName.L:
switch strings.ToUpper(tableInfo.Name.O) {
case infoschema.TableClusterConfig, infoschema.TableClusterLoad, infoschema.TableClusterHardware, infoschema.TableClusterSystemInfo:
p.Extractor = &ClusterTableExtractor{}
case infoschema.TableClusterLog:
p.Extractor = &ClusterLogTableExtractor{}
case infoschema.TableTiDBHotRegionsHistory:
p.Extractor = &HotRegionsHistoryTableExtractor{}
case infoschema.TableInspectionResult:
p.Extractor = &InspectionResultTableExtractor{}
p.QueryTimeRange = b.timeRangeForSummaryTable()
case infoschema.TableInspectionSummary:
p.Extractor = &InspectionSummaryTableExtractor{}
p.QueryTimeRange = b.timeRangeForSummaryTable()
case infoschema.TableInspectionRules:
p.Extractor = &InspectionRuleTableExtractor{}
case infoschema.TableMetricSummary, infoschema.TableMetricSummaryByLabel:
p.Extractor = &MetricSummaryTableExtractor{}
p.QueryTimeRange = b.timeRangeForSummaryTable()
case infoschema.TableSlowQuery:
p.Extractor = &SlowQueryExtractor{}
case infoschema.TableStorageStats:
p.Extractor = &TableStorageStatsExtractor{}
case infoschema.TableTiFlashTables, infoschema.TableTiFlashSegments:
p.Extractor = &TiFlashSystemTableExtractor{}
case infoschema.TableStatementsSummary, infoschema.TableStatementsSummaryHistory:
p.Extractor = &StatementsSummaryExtractor{}
case infoschema.TableTiKVRegionPeers:
p.Extractor = &TikvRegionPeersExtractor{}
case infoschema.TableColumns:
p.Extractor = &ColumnsTableExtractor{}
case infoschema.TableTiKVRegionStatus:
p.Extractor = &TiKVRegionStatusExtractor{tablesID: make([]int64, 0)}
}
}
return p, nil
}
// checkRecursiveView checks whether this view is recursively defined.
func (b *PlanBuilder) checkRecursiveView(dbName model.CIStr, tableName model.CIStr) (func(), error) {
viewFullName := dbName.L + "." + tableName.L
if b.buildingViewStack == nil {
b.buildingViewStack = set.NewStringSet()
}
// If this view has already been on the building stack, it means
// this view contains a recursive definition.
if b.buildingViewStack.Exist(viewFullName) {
return nil, ErrViewRecursive.GenWithStackByArgs(dbName.O, tableName.O)
}
// If the view is being renamed, we return the mysql compatible error message.
if b.capFlag&renameView != 0 && viewFullName == b.renamingViewName {
return nil, ErrNoSuchTable.GenWithStackByArgs(dbName.O, tableName.O)
}
b.buildingViewStack.Insert(viewFullName)
return func() { delete(b.buildingViewStack, viewFullName) }, nil
}
// BuildDataSourceFromView is used to build LogicalPlan from view
func (b *PlanBuilder) BuildDataSourceFromView(ctx context.Context, dbName model.CIStr, tableInfo *model.TableInfo) (LogicalPlan, error) {
viewDepth := b.ctx.GetSessionVars().StmtCtx.ViewDepth
b.ctx.GetSessionVars().StmtCtx.ViewDepth++
deferFunc, err := b.checkRecursiveView(dbName, tableInfo.Name)
if err != nil {
return nil, err
}
defer deferFunc()
charset, collation := b.ctx.GetSessionVars().GetCharsetInfo()
viewParser := parser.New()
viewParser.SetParserConfig(b.ctx.GetSessionVars().BuildParserConfig())
selectNode, err := viewParser.ParseOneStmt(tableInfo.View.SelectStmt, charset, collation)
if err != nil {
return nil, err
}
originalVisitInfo := b.visitInfo
b.visitInfo = make([]visitInfo, 0)
//For the case that views appear in CTE queries,
//we need to save the CTEs after the views are established.
var saveCte []*cteInfo
if len(b.outerCTEs) > 0 {
saveCte = make([]*cteInfo, len(b.outerCTEs))
copy(saveCte, b.outerCTEs)
} else {
saveCte = nil
}
o := b.buildingCTE
b.buildingCTE = false
defer func() {
b.outerCTEs = saveCte
b.buildingCTE = o
}()
selectLogicalPlan, err := b.Build(ctx, selectNode)
if err != nil {
if terror.ErrorNotEqual(err, ErrViewRecursive) &&
terror.ErrorNotEqual(err, ErrNoSuchTable) &&
terror.ErrorNotEqual(err, ErrInternal) &&
terror.ErrorNotEqual(err, ErrFieldNotInGroupBy) &&
terror.ErrorNotEqual(err, ErrMixOfGroupFuncAndFields) &&
terror.ErrorNotEqual(err, ErrViewNoExplain) {
err = ErrViewInvalid.GenWithStackByArgs(dbName.O, tableInfo.Name.O)
}
return nil, err
}
pm := privilege.GetPrivilegeManager(b.ctx)
if viewDepth != 0 &&
b.ctx.GetSessionVars().StmtCtx.InExplainStmt &&
pm != nil &&
!pm.RequestVerification(b.ctx.GetSessionVars().ActiveRoles, dbName.L, tableInfo.Name.L, "", mysql.SelectPriv) {
return nil, ErrViewNoExplain
}
if tableInfo.View.Security == model.SecurityDefiner {
if pm != nil {
for _, v := range b.visitInfo {
if !pm.RequestVerificationWithUser(v.db, v.table, v.column, v.privilege, tableInfo.View.Definer) {
return nil, ErrViewInvalid.GenWithStackByArgs(dbName.O, tableInfo.Name.O)
}
}
}
b.visitInfo = b.visitInfo[:0]
}
b.visitInfo = append(originalVisitInfo, b.visitInfo...)
if b.ctx.GetSessionVars().StmtCtx.InExplainStmt {
b.visitInfo = appendVisitInfo(b.visitInfo, mysql.ShowViewPriv, dbName.L, tableInfo.Name.L, "", ErrViewNoExplain)
}
if len(tableInfo.Columns) != selectLogicalPlan.Schema().Len() {
return nil, ErrViewInvalid.GenWithStackByArgs(dbName.O, tableInfo.Name.O)
}
return b.buildProjUponView(ctx, dbName, tableInfo, selectLogicalPlan)
}
func (b *PlanBuilder) buildProjUponView(_ context.Context, dbName model.CIStr, tableInfo *model.TableInfo, selectLogicalPlan Plan) (LogicalPlan, error) {
columnInfo := tableInfo.Cols()
cols := selectLogicalPlan.Schema().Clone().Columns
outputNamesOfUnderlyingSelect := selectLogicalPlan.OutputNames().Shallow()
// In the old version of VIEW implementation, tableInfo.View.Cols is used to
// store the origin columns' names of the underlying SelectStmt used when
// creating the view.
if tableInfo.View.Cols != nil {
cols = cols[:0]
outputNamesOfUnderlyingSelect = outputNamesOfUnderlyingSelect[:0]
for _, info := range columnInfo {
idx := expression.FindFieldNameIdxByColName(selectLogicalPlan.OutputNames(), info.Name.L)
if idx == -1 {
return nil, ErrViewInvalid.GenWithStackByArgs(dbName.O, tableInfo.Name.O)
}
cols = append(cols, selectLogicalPlan.Schema().Columns[idx])
outputNamesOfUnderlyingSelect = append(outputNamesOfUnderlyingSelect, selectLogicalPlan.OutputNames()[idx])
}
}
projSchema := expression.NewSchema(make([]*expression.Column, 0, len(tableInfo.Columns))...)
projExprs := make([]expression.Expression, 0, len(tableInfo.Columns))
projNames := make(types.NameSlice, 0, len(tableInfo.Columns))
for i, name := range outputNamesOfUnderlyingSelect {
origColName := name.ColName
if tableInfo.View.Cols != nil {
origColName = tableInfo.View.Cols[i]
}
projNames = append(projNames, &types.FieldName{
// TblName is the of view instead of the name of the underlying table.
TblName: tableInfo.Name,
OrigTblName: name.OrigTblName,
ColName: columnInfo[i].Name,
OrigColName: origColName,
DBName: dbName,
})
projSchema.Append(&expression.Column{
UniqueID: cols[i].UniqueID,
RetType: cols[i].GetType(),
})
projExprs = append(projExprs, cols[i])
}
projUponView := LogicalProjection{Exprs: projExprs}.Init(b.ctx, b.getSelectOffset())
projUponView.names = projNames
projUponView.SetChildren(selectLogicalPlan.(LogicalPlan))
projUponView.SetSchema(projSchema)
return projUponView, nil
}
// buildApplyWithJoinType builds apply plan with outerPlan and innerPlan, which apply join with particular join type for
// every row from outerPlan and the whole innerPlan.
func (b *PlanBuilder) buildApplyWithJoinType(outerPlan, innerPlan LogicalPlan, tp JoinType) LogicalPlan {
b.optFlag = b.optFlag | flagPredicatePushDown | flagBuildKeyInfo | flagDecorrelate
setIsInApplyForCTE(innerPlan)
ap := LogicalApply{LogicalJoin: LogicalJoin{JoinType: tp}}.Init(b.ctx, b.getSelectOffset())
ap.SetChildren(outerPlan, innerPlan)
ap.names = make([]*types.FieldName, outerPlan.Schema().Len()+innerPlan.Schema().Len())
copy(ap.names, outerPlan.OutputNames())
ap.SetSchema(expression.MergeSchema(outerPlan.Schema(), innerPlan.Schema()))
// Note that, tp can only be LeftOuterJoin or InnerJoin, so we don't consider other outer joins.
if tp == LeftOuterJoin {
b.optFlag = b.optFlag | flagEliminateOuterJoin
resetNotNullFlag(ap.schema, outerPlan.Schema().Len(), ap.schema.Len())
}
for i := outerPlan.Schema().Len(); i < ap.Schema().Len(); i++ {
ap.names[i] = types.EmptyName
}
return ap
}
// buildSemiApply builds apply plan with outerPlan and innerPlan, which apply semi-join for every row from outerPlan and the whole innerPlan.
func (b *PlanBuilder) buildSemiApply(outerPlan, innerPlan LogicalPlan, condition []expression.Expression, asScalar, not, considerRewrite bool) (LogicalPlan, error) {
b.optFlag = b.optFlag | flagPredicatePushDown | flagBuildKeyInfo | flagDecorrelate
join, err := b.buildSemiJoin(outerPlan, innerPlan, condition, asScalar, not, considerRewrite)
if err != nil {
return nil, err
}
setIsInApplyForCTE(innerPlan)
ap := &LogicalApply{LogicalJoin: *join}
ap.tp = plancodec.TypeApply
ap.self = ap
return ap, nil
}
// setIsInApplyForCTE indicates CTE is the in inner side of Apply,
// the storage of cte needs to be reset for each outer row.
// It's better to handle this in CTEExec.Close(), but cte storage is closed when SQL is finished.
func setIsInApplyForCTE(p LogicalPlan) {
switch x := p.(type) {
case *LogicalCTE:
x.cte.IsInApply = true
setIsInApplyForCTE(x.cte.seedPartLogicalPlan)
if x.cte.recursivePartLogicalPlan != nil {
setIsInApplyForCTE(x.cte.recursivePartLogicalPlan)
}
default:
for _, child := range p.Children() {
setIsInApplyForCTE(child)
}
}
}
func (b *PlanBuilder) buildMaxOneRow(p LogicalPlan) LogicalPlan {
maxOneRow := LogicalMaxOneRow{}.Init(b.ctx, b.getSelectOffset())
maxOneRow.SetChildren(p)
return maxOneRow
}
func (b *PlanBuilder) buildSemiJoin(outerPlan, innerPlan LogicalPlan, onCondition []expression.Expression, asScalar, not, forceRewrite bool) (*LogicalJoin, error) {
joinPlan := LogicalJoin{}.Init(b.ctx, b.getSelectOffset())
for i, expr := range onCondition {
onCondition[i] = expr.Decorrelate(outerPlan.Schema())
}
joinPlan.SetChildren(outerPlan, innerPlan)
joinPlan.AttachOnConds(onCondition)
joinPlan.names = make([]*types.FieldName, outerPlan.Schema().Len(), outerPlan.Schema().Len()+innerPlan.Schema().Len()+1)
copy(joinPlan.names, outerPlan.OutputNames())
if asScalar {
newSchema := outerPlan.Schema().Clone()
newSchema.Append(&expression.Column{
RetType: types.NewFieldType(mysql.TypeTiny),
UniqueID: b.ctx.GetSessionVars().AllocPlanColumnID(),
})
joinPlan.names = append(joinPlan.names, types.EmptyName)
joinPlan.SetSchema(newSchema)
if not {
joinPlan.JoinType = AntiLeftOuterSemiJoin
} else {
joinPlan.JoinType = LeftOuterSemiJoin
}
} else {
joinPlan.SetSchema(outerPlan.Schema().Clone())
if not {
joinPlan.JoinType = AntiSemiJoin
} else {
joinPlan.JoinType = SemiJoin
}
}
// Apply forces to choose hash join currently, so don't worry the hints will take effect if the semi join is in one apply.
if b.TableHints() != nil {
hintInfo := b.TableHints()
outerAlias := extractTableAlias(outerPlan, joinPlan.blockOffset)
innerAlias := extractTableAlias(innerPlan, joinPlan.blockOffset)
if hintInfo.ifPreferMergeJoin(outerAlias, innerAlias) {
joinPlan.preferJoinType |= preferMergeJoin
}
if hintInfo.ifPreferHashJoin(outerAlias, innerAlias) {
joinPlan.preferJoinType |= preferHashJoin
}
if hintInfo.ifPreferINLJ(innerAlias) {
joinPlan.preferJoinType = preferRightAsINLJInner
}
if hintInfo.ifPreferINLHJ(innerAlias) {
joinPlan.preferJoinType = preferRightAsINLHJInner
}
if hintInfo.ifPreferINLMJ(innerAlias) {
joinPlan.preferJoinType = preferRightAsINLMJInner
}
if hintInfo.ifPreferHJBuild(outerAlias) {
joinPlan.preferJoinType |= preferLeftAsHJBuild
}
if hintInfo.ifPreferHJBuild(innerAlias) {
joinPlan.preferJoinType |= preferRightAsHJBuild
}
if hintInfo.ifPreferHJProbe(outerAlias) {
joinPlan.preferJoinType |= preferLeftAsHJProbe
}
if hintInfo.ifPreferHJProbe(innerAlias) {
joinPlan.preferJoinType |= preferRightAsHJProbe
}
// If there're multiple join hints, they're conflict.
if bits.OnesCount(joinPlan.preferJoinType) > 1 {
return nil, errors.New("Join hints are conflict, you can only specify one type of join")
}
}
if forceRewrite {
joinPlan.preferJoinType |= preferRewriteSemiJoin
b.optFlag |= flagSemiJoinRewrite
}
return joinPlan, nil
}
func getTableOffset(names []*types.FieldName, handleName *types.FieldName) (int, error) {
for i, name := range names {
if name.DBName.L == handleName.DBName.L && name.TblName.L == handleName.TblName.L {
return i, nil
}
}
return -1, errors.Errorf("Couldn't get column information when do update/delete")
}
// TblColPosInfo represents an mapper from column index to handle index.
type TblColPosInfo struct {
TblID int64
// Start and End represent the ordinal range [Start, End) of the consecutive columns.
Start, End int
// HandleOrdinal represents the ordinal of the handle column.
HandleCols HandleCols
}
// TblColPosInfoSlice attaches the methods of sort.Interface to []TblColPosInfos sorting in increasing order.
type TblColPosInfoSlice []TblColPosInfo
// Len implements sort.Interface#Len.
func (c TblColPosInfoSlice) Len() int {
return len(c)
}
// Swap implements sort.Interface#Swap.
func (c TblColPosInfoSlice) Swap(i, j int) {
c[i], c[j] = c[j], c[i]
}
// Less implements sort.Interface#Less.
func (c TblColPosInfoSlice) Less(i, j int) bool {
return c[i].Start < c[j].Start
}
// FindTblIdx finds the ordinal of the corresponding access column.
func (c TblColPosInfoSlice) FindTblIdx(colOrdinal int) (int, bool) {
if len(c) == 0 {
return 0, false
}
// find the smallest index of the range that its start great than colOrdinal.
// @see https://godoc.org/sort#Search
rangeBehindOrdinal := sort.Search(len(c), func(i int) bool { return c[i].Start > colOrdinal })
if rangeBehindOrdinal == 0 {
return 0, false
}
return rangeBehindOrdinal - 1, true
}
// buildColumns2Handle builds columns to handle mapping.
func buildColumns2Handle(
names []*types.FieldName,
tblID2Handle map[int64][]HandleCols,
tblID2Table map[int64]table.Table,
onlyWritableCol bool,
) (TblColPosInfoSlice, error) {
var cols2Handles TblColPosInfoSlice
for tblID, handleCols := range tblID2Handle {
tbl := tblID2Table[tblID]
var tblLen int
if onlyWritableCol {
tblLen = len(tbl.WritableCols())
} else {
tblLen = len(tbl.Cols())
}
for _, handleCol := range handleCols {
offset, err := getTableOffset(names, names[handleCol.GetCol(0).Index])
if err != nil {
return nil, err
}
end := offset + tblLen
cols2Handles = append(cols2Handles, TblColPosInfo{tblID, offset, end, handleCol})
}
}
sort.Sort(cols2Handles)
return cols2Handles, nil
}
func (b *PlanBuilder) buildUpdate(ctx context.Context, update *ast.UpdateStmt) (Plan, error) {
b.pushSelectOffset(0)
b.pushTableHints(update.TableHints, 0)
defer func() {
b.popSelectOffset()
// table hints are only visible in the current UPDATE statement.
b.popTableHints()
}()
b.inUpdateStmt = true
b.isForUpdateRead = true
if update.With != nil {
l := len(b.outerCTEs)
defer func() {
b.outerCTEs = b.outerCTEs[:l]
}()
err := b.buildWith(ctx, update.With)
if err != nil {
return nil, err
}
}
p, err := b.buildResultSetNode(ctx, update.TableRefs.TableRefs, false)
if err != nil {
return nil, err
}
var tableList []*ast.TableName
tableList = extractTableList(update.TableRefs.TableRefs, tableList, false)
for _, t := range tableList {
dbName := t.Schema.L
if dbName == "" {
dbName = b.ctx.GetSessionVars().CurrentDB
}
b.visitInfo = appendVisitInfo(b.visitInfo, mysql.SelectPriv, dbName, t.Name.L, "", nil)
}
oldSchemaLen := p.Schema().Len()
if update.Where != nil {
p, err = b.buildSelection(ctx, p, update.Where, nil)
if err != nil {
return nil, err
}
}
if b.ctx.GetSessionVars().TxnCtx.IsPessimistic {
if update.TableRefs.TableRefs.Right == nil {
// buildSelectLock is an optimization that can reduce RPC call.
// We only need do this optimization for single table update which is the most common case.
// When TableRefs.Right is nil, it is single table update.
p, err = b.buildSelectLock(p, &ast.SelectLockInfo{
LockType: ast.SelectLockForUpdate,
})
if err != nil {
return nil, err
}
}
}
if update.Order != nil {
p, err = b.buildSort(ctx, p, update.Order.Items, nil, nil)
if err != nil {
return nil, err
}
}
if update.Limit != nil {
p, err = b.buildLimit(p, update.Limit)
if err != nil {
return nil, err
}
}
// Add project to freeze the order of output columns.
proj := LogicalProjection{Exprs: expression.Column2Exprs(p.Schema().Columns[:oldSchemaLen])}.Init(b.ctx, b.getSelectOffset())
proj.SetSchema(expression.NewSchema(make([]*expression.Column, oldSchemaLen)...))
proj.names = make(types.NameSlice, len(p.OutputNames()))
copy(proj.names, p.OutputNames())
copy(proj.schema.Columns, p.Schema().Columns[:oldSchemaLen])
proj.SetChildren(p)
p = proj
utlr := &updatableTableListResolver{}
update.Accept(utlr)
orderedList, np, allAssignmentsAreConstant, err := b.buildUpdateLists(ctx, utlr.updatableTableList, update.List, p)
if err != nil {
return nil, err
}
p = np
updt := Update{
OrderedList: orderedList,
AllAssignmentsAreConstant: allAssignmentsAreConstant,
VirtualAssignmentsOffset: len(update.List),
}.Init(b.ctx)
updt.names = p.OutputNames()
// We cannot apply projection elimination when building the subplan, because
// columns in orderedList cannot be resolved. (^flagEliminateProjection should also be applied in postOptimize)
updt.SelectPlan, _, err = DoOptimize(ctx, b.ctx, b.optFlag&^flagEliminateProjection, p)
if err != nil {
return nil, err
}
err = updt.ResolveIndices()
if err != nil {
return nil, err
}
tblID2Handle, err := resolveIndicesForTblID2Handle(b.handleHelper.tailMap(), updt.SelectPlan.Schema())
if err != nil {
return nil, err
}
tblID2table := make(map[int64]table.Table, len(tblID2Handle))
for id := range tblID2Handle {
tblID2table[id], _ = b.is.TableByID(id)
}
updt.TblColPosInfos, err = buildColumns2Handle(updt.OutputNames(), tblID2Handle, tblID2table, true)
updt.PartitionedTable = b.partitionedTable
updt.tblID2Table = tblID2table
return updt, err
}
type tblUpdateInfo struct {
name string
pkUpdated bool
partitionColUpdated bool
}
// CheckUpdateList checks all related columns in updatable state.
func CheckUpdateList(assignFlags []int, updt *Update, newTblID2Table map[int64]table.Table) error {
updateFromOtherAlias := make(map[int64]tblUpdateInfo)
for _, content := range updt.TblColPosInfos {
tbl := newTblID2Table[content.TblID]
flags := assignFlags[content.Start:content.End]
var update, updatePK, updatePartitionCol bool
var partitionColumnNames []model.CIStr
if pt, ok := tbl.(table.PartitionedTable); ok && pt != nil {
partitionColumnNames = pt.GetPartitionColumnNames()
}
for i, col := range tbl.WritableCols() {
// schema may be changed between building plan and building executor
// If i >= len(flags), it means the target table has been added columns, then we directly skip the check
if i >= len(flags) {
continue
}
if flags[i] < 0 {
continue
}
if col.State != model.StatePublic {
return ErrUnknownColumn.GenWithStackByArgs(col.Name, clauseMsg[fieldList])
}
update = true
if mysql.HasPriKeyFlag(col.GetFlag()) {
updatePK = true
}
for _, partColName := range partitionColumnNames {
if col.Name.L == partColName.L {
updatePartitionCol = true
}
}
}
if update {
// Check for multi-updates on primary key,
// see https://dev.mysql.com/doc/mysql-errors/5.7/en/server-error-reference.html#error_er_multi_update_key_conflict
if otherTable, ok := updateFromOtherAlias[tbl.Meta().ID]; ok {
if otherTable.pkUpdated || updatePK || otherTable.partitionColUpdated || updatePartitionCol {
return ErrMultiUpdateKeyConflict.GenWithStackByArgs(otherTable.name, updt.names[content.Start].TblName.O)
}
} else {
updateFromOtherAlias[tbl.Meta().ID] = tblUpdateInfo{
name: updt.names[content.Start].TblName.O,
pkUpdated: updatePK,
partitionColUpdated: updatePartitionCol,
}
}
}
}
return nil
}
// If tl is CTE, its TableInfo will be nil.
// Only used in build plan from AST after preprocess.
func isCTE(tl *ast.TableName) bool {
return tl.TableInfo == nil
}
func (b *PlanBuilder) buildUpdateLists(ctx context.Context, tableList []*ast.TableName, list []*ast.Assignment, p LogicalPlan) (newList []*expression.Assignment, po LogicalPlan, allAssignmentsAreConstant bool, e error) {
b.curClause = fieldList
// modifyColumns indicates which columns are in set list,
// and if it is set to `DEFAULT`
modifyColumns := make(map[string]bool, p.Schema().Len())
var columnsIdx map[*ast.ColumnName]int
cacheColumnsIdx := false
if len(p.OutputNames()) > 16 {
cacheColumnsIdx = true
columnsIdx = make(map[*ast.ColumnName]int, len(list))
}
for _, assign := range list {
idx, err := expression.FindFieldName(p.OutputNames(), assign.Column)
if err != nil {
return nil, nil, false, err
}
if idx < 0 {
return nil, nil, false, ErrUnknownColumn.GenWithStackByArgs(assign.Column.Name, "field list")
}
if cacheColumnsIdx {
columnsIdx[assign.Column] = idx
}
name := p.OutputNames()[idx]
foundListItem := false
for _, tl := range tableList {
if (tl.Schema.L == "" || tl.Schema.L == name.DBName.L) && (tl.Name.L == name.TblName.L) {
if isCTE(tl) || tl.TableInfo.IsView() || tl.TableInfo.IsSequence() {
return nil, nil, false, ErrNonUpdatableTable.GenWithStackByArgs(name.TblName.O, "UPDATE")
}
foundListItem = true
}
}
if !foundListItem {
// For case like:
// 1: update (select * from t1) t1 set b = 1111111 ----- (no updatable table here)
// 2: update (select 1 as a) as t, t1 set a=1 ----- (updatable t1 don't have column a)
// --- subQuery is not counted as updatable table.
return nil, nil, false, ErrNonUpdatableTable.GenWithStackByArgs(name.TblName.O, "UPDATE")
}
columnFullName := fmt.Sprintf("%s.%s.%s", name.DBName.L, name.TblName.L, name.ColName.L)
// We save a flag for the column in map `modifyColumns`
// This flag indicated if assign keyword `DEFAULT` to the column
modifyColumns[columnFullName] = IsDefaultExprSameColumn(p.OutputNames()[idx:idx+1], assign.Expr)
}
// If columns in set list contains generated columns, raise error.
// And, fill virtualAssignments here; that's for generated columns.
virtualAssignments := make([]*ast.Assignment, 0)
for _, tn := range tableList {
if isCTE(tn) || tn.TableInfo.IsView() || tn.TableInfo.IsSequence() {
continue
}
tableInfo := tn.TableInfo
tableVal, found := b.is.TableByID(tableInfo.ID)
if !found {
return nil, nil, false, infoschema.ErrTableNotExists.GenWithStackByArgs(tn.DBInfo.Name.O, tableInfo.Name.O)
}
for i, colInfo := range tableVal.Cols() {
if !colInfo.IsGenerated() {
continue
}
columnFullName := fmt.Sprintf("%s.%s.%s", tn.DBInfo.Name.L, tn.Name.L, colInfo.Name.L)
isDefault, ok := modifyColumns[columnFullName]
if ok && colInfo.Hidden {
return nil, nil, false, ErrUnknownColumn.GenWithStackByArgs(colInfo.Name, clauseMsg[fieldList])
}
// Note: For INSERT, REPLACE, and UPDATE, if a generated column is inserted into, replaced, or updated explicitly, the only permitted value is DEFAULT.
// see https://dev.mysql.com/doc/refman/8.0/en/create-table-generated-columns.html
if ok && !isDefault {
return nil, nil, false, ErrBadGeneratedColumn.GenWithStackByArgs(colInfo.Name.O, tableInfo.Name.O)
}
virtualAssignments = append(virtualAssignments, &ast.Assignment{
Column: &ast.ColumnName{Schema: tn.Schema, Table: tn.Name, Name: colInfo.Name},
Expr: tableVal.Cols()[i].GeneratedExpr,
})
}
}
allAssignmentsAreConstant = true
newList = make([]*expression.Assignment, 0, p.Schema().Len())
tblDbMap := make(map[string]string, len(tableList))
for _, tbl := range tableList {
if isCTE(tbl) {
continue
}
tblDbMap[tbl.Name.L] = tbl.DBInfo.Name.L
}
allAssignments := append(list, virtualAssignments...)
dependentColumnsModified := make(map[int64]bool)
for i, assign := range allAssignments {
var idx int
var err error
if cacheColumnsIdx {
if i, ok := columnsIdx[assign.Column]; ok {
idx = i
} else {
idx, err = expression.FindFieldName(p.OutputNames(), assign.Column)
}
} else {
idx, err = expression.FindFieldName(p.OutputNames(), assign.Column)
}
if err != nil {
return nil, nil, false, err
}
col := p.Schema().Columns[idx]
name := p.OutputNames()[idx]
var newExpr expression.Expression
var np LogicalPlan
if i < len(list) {
// If assign `DEFAULT` to column, fill the `defaultExpr.Name` before rewrite expression
if expr := extractDefaultExpr(assign.Expr); expr != nil {
expr.Name = assign.Column
}
newExpr, np, err = b.rewrite(ctx, assign.Expr, p, nil, false)
if err != nil {
return nil, nil, false, err
}
dependentColumnsModified[col.UniqueID] = true
} else {
// rewrite with generation expression
rewritePreprocess := func(assign *ast.Assignment) func(expr ast.Node) ast.Node {
return func(expr ast.Node) ast.Node {
switch x := expr.(type) {
case *ast.ColumnName:
return &ast.ColumnName{
Schema: assign.Column.Schema,
Table: assign.Column.Table,
Name: x.Name,
}
default:
return expr
}
}
}
newExpr, np, err = b.rewriteWithPreprocess(ctx, assign.Expr, p, nil, nil, false, rewritePreprocess(assign))
if err != nil {
return nil, nil, false, err
}
// check if the column is modified
dependentColumns := expression.ExtractDependentColumns(newExpr)
var isModified bool
for _, col := range dependentColumns {
if dependentColumnsModified[col.UniqueID] {
isModified = true
break
}
}
// skip unmodified generated columns
if !isModified {
continue
}
}
if _, isConst := newExpr.(*expression.Constant); !isConst {
allAssignmentsAreConstant = false
}
p = np
if col, ok := newExpr.(*expression.Column); ok {
b.ctx.GetSessionVars().StmtCtx.ColRefFromUpdatePlan = append(b.ctx.GetSessionVars().StmtCtx.ColRefFromUpdatePlan, col.UniqueID)
}
newList = append(newList, &expression.Assignment{Col: col, ColName: name.ColName, Expr: newExpr})
dbName := name.DBName.L
// To solve issue#10028, we need to get database name by the table alias name.
if dbNameTmp, ok := tblDbMap[name.TblName.L]; ok {
dbName = dbNameTmp
}
if dbName == "" {
dbName = b.ctx.GetSessionVars().CurrentDB
}
b.visitInfo = appendVisitInfo(b.visitInfo, mysql.UpdatePriv, dbName, name.OrigTblName.L, "", nil)
}
return newList, p, allAssignmentsAreConstant, nil
}
// extractDefaultExpr extract a `DefaultExpr` from `ExprNode`,
// If it is a `DEFAULT` function like `DEFAULT(a)`, return nil.
// Only if it is `DEFAULT` keyword, it will return the `DefaultExpr`.
func extractDefaultExpr(node ast.ExprNode) *ast.DefaultExpr {
if expr, ok := node.(*ast.DefaultExpr); ok && expr.Name == nil {
return expr
}
return nil
}
// IsDefaultExprSameColumn - DEFAULT or col = DEFAULT(col)
func IsDefaultExprSameColumn(names types.NameSlice, node ast.ExprNode) bool {
if expr, ok := node.(*ast.DefaultExpr); ok {
if expr.Name == nil {
// col = DEFAULT
return true
}
refIdx, err := expression.FindFieldName(names, expr.Name)
if refIdx == 0 && err == nil {
// col = DEFAULT(col)
return true
}
}
return false
}
func (b *PlanBuilder) buildDelete(ctx context.Context, ds *ast.DeleteStmt) (Plan, error) {
b.pushSelectOffset(0)
b.pushTableHints(ds.TableHints, 0)
defer func() {
b.popSelectOffset()
// table hints are only visible in the current DELETE statement.
b.popTableHints()
}()
b.inDeleteStmt = true
b.isForUpdateRead = true
if ds.With != nil {
l := len(b.outerCTEs)
defer func() {
b.outerCTEs = b.outerCTEs[:l]
}()
err := b.buildWith(ctx, ds.With)
if err != nil {
return nil, err
}
}
p, err := b.buildResultSetNode(ctx, ds.TableRefs.TableRefs, false)
if err != nil {
return nil, err
}
oldSchema := p.Schema()
oldLen := oldSchema.Len()
// For explicit column usage, should use the all-public columns.
if ds.Where != nil {
p, err = b.buildSelection(ctx, p, ds.Where, nil)
if err != nil {
return nil, err
}
}
if b.ctx.GetSessionVars().TxnCtx.IsPessimistic {
if !ds.IsMultiTable {
p, err = b.buildSelectLock(p, &ast.SelectLockInfo{
LockType: ast.SelectLockForUpdate,
})
if err != nil {
return nil, err
}
}
}
if ds.Order != nil {
p, err = b.buildSort(ctx, p, ds.Order.Items, nil, nil)
if err != nil {
return nil, err
}
}
if ds.Limit != nil {
p, err = b.buildLimit(p, ds.Limit)
if err != nil {
return nil, err
}
}
// If the delete is non-qualified it does not require Select Priv
if ds.Where == nil && ds.Order == nil {
b.popVisitInfo()
}
var authErr error
sessionVars := b.ctx.GetSessionVars()
proj := LogicalProjection{Exprs: expression.Column2Exprs(p.Schema().Columns[:oldLen])}.Init(b.ctx, b.getSelectOffset())
proj.SetChildren(p)
proj.SetSchema(oldSchema.Clone())
proj.names = p.OutputNames()[:oldLen]
p = proj
handleColsMap := b.handleHelper.tailMap()
for _, cols := range handleColsMap {
for _, col := range cols {
for i := 0; i < col.NumCols(); i++ {
exprCol := col.GetCol(i)
if proj.Schema().Contains(exprCol) {
continue
}
proj.Exprs = append(proj.Exprs, exprCol)
proj.Schema().Columns = append(proj.Schema().Columns, exprCol)
proj.names = append(proj.names, types.EmptyName)
}
}
}
del := Delete{
IsMultiTable: ds.IsMultiTable,
}.Init(b.ctx)
del.names = p.OutputNames()
del.SelectPlan, _, err = DoOptimize(ctx, b.ctx, b.optFlag, p)
if err != nil {
return nil, err
}
tblID2Handle, err := resolveIndicesForTblID2Handle(handleColsMap, del.SelectPlan.Schema())
if err != nil {
return nil, err
}
// Collect visitInfo.
if ds.Tables != nil {
// Delete a, b from a, b, c, d... add a and b.
updatableList := make(map[string]bool)
tbInfoList := make(map[string]*ast.TableName)
collectTableName(ds.TableRefs.TableRefs, &updatableList, &tbInfoList)
for _, tn := range ds.Tables.Tables {
var canUpdate, foundMatch = false, false
name := tn.Name.L
if tn.Schema.L == "" {
canUpdate, foundMatch = updatableList[name]
}
if !foundMatch {
if tn.Schema.L == "" {
name = model.NewCIStr(b.ctx.GetSessionVars().CurrentDB).L + "." + tn.Name.L
} else {
name = tn.Schema.L + "." + tn.Name.L
}
canUpdate, foundMatch = updatableList[name]
}
// check sql like: `delete b from (select * from t) as a, t`
if !foundMatch {
return nil, ErrUnknownTable.GenWithStackByArgs(tn.Name.O, "MULTI DELETE")
}
// check sql like: `delete a from (select * from t) as a, t`
if !canUpdate {
return nil, ErrNonUpdatableTable.GenWithStackByArgs(tn.Name.O, "DELETE")
}
tb := tbInfoList[name]
tn.DBInfo = tb.DBInfo
tn.TableInfo = tb.TableInfo
if tn.TableInfo.IsView() {
return nil, errors.Errorf("delete view %s is not supported now", tn.Name.O)
}
if tn.TableInfo.IsSequence() {
return nil, errors.Errorf("delete sequence %s is not supported now", tn.Name.O)
}
if sessionVars.User != nil {
authErr = ErrTableaccessDenied.FastGenByArgs("DELETE", sessionVars.User.AuthUsername, sessionVars.User.AuthHostname, tb.Name.L)
}
b.visitInfo = appendVisitInfo(b.visitInfo, mysql.DeletePriv, tb.DBInfo.Name.L, tb.Name.L, "", authErr)
}
} else {
// Delete from a, b, c, d.
var tableList []*ast.TableName
tableList = extractTableList(ds.TableRefs.TableRefs, tableList, false)
for _, v := range tableList {
if isCTE(v) {
return nil, ErrNonUpdatableTable.GenWithStackByArgs(v.Name.O, "DELETE")
}
if v.TableInfo.IsView() {
return nil, errors.Errorf("delete view %s is not supported now", v.Name.O)
}
if v.TableInfo.IsSequence() {
return nil, errors.Errorf("delete sequence %s is not supported now", v.Name.O)
}
dbName := v.Schema.L
if dbName == "" {
dbName = b.ctx.GetSessionVars().CurrentDB
}
if sessionVars.User != nil {
authErr = ErrTableaccessDenied.FastGenByArgs("DELETE", sessionVars.User.AuthUsername, sessionVars.User.AuthHostname, v.Name.L)
}
b.visitInfo = appendVisitInfo(b.visitInfo, mysql.DeletePriv, dbName, v.Name.L, "", authErr)
}
}
if del.IsMultiTable {
// tblID2TableName is the table map value is an array which contains table aliases.
// Table ID may not be unique for deleting multiple tables, for statements like
// `delete from t as t1, t as t2`, the same table has two alias, we have to identify a table
// by its alias instead of ID.
tblID2TableName := make(map[int64][]*ast.TableName, len(ds.Tables.Tables))
for _, tn := range ds.Tables.Tables {
tblID2TableName[tn.TableInfo.ID] = append(tblID2TableName[tn.TableInfo.ID], tn)
}
tblID2Handle = del.cleanTblID2HandleMap(tblID2TableName, tblID2Handle, del.names)
}
tblID2table := make(map[int64]table.Table, len(tblID2Handle))
for id := range tblID2Handle {
tblID2table[id], _ = b.is.TableByID(id)
}
del.TblColPosInfos, err = buildColumns2Handle(del.names, tblID2Handle, tblID2table, false)
return del, err
}
func resolveIndicesForTblID2Handle(tblID2Handle map[int64][]HandleCols, schema *expression.Schema) (map[int64][]HandleCols, error) {
newMap := make(map[int64][]HandleCols, len(tblID2Handle))
for i, cols := range tblID2Handle {
for _, col := range cols {
resolvedCol, err := col.ResolveIndices(schema)
if err != nil {
return nil, err
}
newMap[i] = append(newMap[i], resolvedCol)
}
}
return newMap, nil
}
func (p *Delete) cleanTblID2HandleMap(
tablesToDelete map[int64][]*ast.TableName,
tblID2Handle map[int64][]HandleCols,
outputNames []*types.FieldName,
) map[int64][]HandleCols {
for id, cols := range tblID2Handle {
names, ok := tablesToDelete[id]
if !ok {
delete(tblID2Handle, id)
continue
}
for i := len(cols) - 1; i >= 0; i-- {
hCols := cols[i]
var hasMatch bool
for j := 0; j < hCols.NumCols(); j++ {
if p.matchingDeletingTable(names, outputNames[hCols.GetCol(j).Index]) {
hasMatch = true
break
}
}
if !hasMatch {
cols = append(cols[:i], cols[i+1:]...)
}
}
if len(cols) == 0 {
delete(tblID2Handle, id)
continue
}
tblID2Handle[id] = cols
}
return tblID2Handle
}
// matchingDeletingTable checks whether this column is from the table which is in the deleting list.
func (p *Delete) matchingDeletingTable(names []*ast.TableName, name *types.FieldName) bool {
for _, n := range names {
if (name.DBName.L == "" || name.DBName.L == n.DBInfo.Name.L) && name.TblName.L == n.Name.L {
return true
}
}
return false
}
func getWindowName(name string) string {
if name == "" {
return "<unnamed window>"
}
return name
}
// buildProjectionForWindow builds the projection for expressions in the window specification that is not an column,
// so after the projection, window functions only needs to deal with columns.
func (b *PlanBuilder) buildProjectionForWindow(ctx context.Context, p LogicalPlan, spec *ast.WindowSpec, args []ast.ExprNode, aggMap map[*ast.AggregateFuncExpr]int) (LogicalPlan, []property.SortItem, []property.SortItem, []expression.Expression, error) {
b.optFlag |= flagEliminateProjection
var partitionItems, orderItems []*ast.ByItem
if spec.PartitionBy != nil {
partitionItems = spec.PartitionBy.Items
}
if spec.OrderBy != nil {
orderItems = spec.OrderBy.Items
}
projLen := len(p.Schema().Columns) + len(partitionItems) + len(orderItems) + len(args)
proj := LogicalProjection{Exprs: make([]expression.Expression, 0, projLen)}.Init(b.ctx, b.getSelectOffset())
proj.SetSchema(expression.NewSchema(make([]*expression.Column, 0, projLen)...))
proj.names = make([]*types.FieldName, p.Schema().Len(), projLen)
for _, col := range p.Schema().Columns {
proj.Exprs = append(proj.Exprs, col)
proj.schema.Append(col)
}
copy(proj.names, p.OutputNames())
propertyItems := make([]property.SortItem, 0, len(partitionItems)+len(orderItems))
var err error
p, propertyItems, err = b.buildByItemsForWindow(ctx, p, proj, partitionItems, propertyItems, aggMap)
if err != nil {
return nil, nil, nil, nil, err
}
lenPartition := len(propertyItems)
p, propertyItems, err = b.buildByItemsForWindow(ctx, p, proj, orderItems, propertyItems, aggMap)
if err != nil {
return nil, nil, nil, nil, err
}
newArgList := make([]expression.Expression, 0, len(args))
for _, arg := range args {
newArg, np, err := b.rewrite(ctx, arg, p, aggMap, true)
if err != nil {
return nil, nil, nil, nil, err
}
p = np
switch newArg.(type) {
case *expression.Column, *expression.Constant:
newArgList = append(newArgList, newArg.Clone())
continue
}
proj.Exprs = append(proj.Exprs, newArg)
proj.names = append(proj.names, types.EmptyName)
col := &expression.Column{
UniqueID: b.ctx.GetSessionVars().AllocPlanColumnID(),
RetType: newArg.GetType(),
}
proj.schema.Append(col)
newArgList = append(newArgList, col)
}
proj.SetChildren(p)
return proj, propertyItems[:lenPartition], propertyItems[lenPartition:], newArgList, nil
}
func (b *PlanBuilder) buildArgs4WindowFunc(ctx context.Context, p LogicalPlan, args []ast.ExprNode, aggMap map[*ast.AggregateFuncExpr]int) ([]expression.Expression, error) {
b.optFlag |= flagEliminateProjection
newArgList := make([]expression.Expression, 0, len(args))
// use below index for created a new col definition
// it's okay here because we only want to return the args used in window function
newColIndex := 0
for _, arg := range args {
newArg, np, err := b.rewrite(ctx, arg, p, aggMap, true)
if err != nil {
return nil, err
}
p = np
switch newArg.(type) {
case *expression.Column, *expression.Constant:
newArgList = append(newArgList, newArg.Clone())
continue
}
col := &expression.Column{
UniqueID: b.ctx.GetSessionVars().AllocPlanColumnID(),
RetType: newArg.GetType(),
}
newColIndex += 1
newArgList = append(newArgList, col)
}
return newArgList, nil
}
func (b *PlanBuilder) buildByItemsForWindow(
ctx context.Context,
p LogicalPlan,
proj *LogicalProjection,
items []*ast.ByItem,
retItems []property.SortItem,
aggMap map[*ast.AggregateFuncExpr]int,
) (LogicalPlan, []property.SortItem, error) {
transformer := &itemTransformer{}
for _, item := range items {
newExpr, _ := item.Expr.Accept(transformer)
item.Expr = newExpr.(ast.ExprNode)
it, np, err := b.rewrite(ctx, item.Expr, p, aggMap, true)
if err != nil {
return nil, nil, err
}
p = np
if it.GetType().GetType() == mysql.TypeNull {
continue
}
if col, ok := it.(*expression.Column); ok {
retItems = append(retItems, property.SortItem{Col: col, Desc: item.Desc})
continue
}
proj.Exprs = append(proj.Exprs, it)
proj.names = append(proj.names, types.EmptyName)
col := &expression.Column{
UniqueID: b.ctx.GetSessionVars().AllocPlanColumnID(),
RetType: it.GetType(),
}
proj.schema.Append(col)
retItems = append(retItems, property.SortItem{Col: col, Desc: item.Desc})
}
return p, retItems, nil
}
// buildWindowFunctionFrameBound builds the bounds of window function frames.
// For type `Rows`, the bound expr must be an unsigned integer.
// For type `Range`, the bound expr must be temporal or numeric types.
func (b *PlanBuilder) buildWindowFunctionFrameBound(_ context.Context, spec *ast.WindowSpec, orderByItems []property.SortItem, boundClause *ast.FrameBound) (*FrameBound, error) {
frameType := spec.Frame.Type
bound := &FrameBound{Type: boundClause.Type, UnBounded: boundClause.UnBounded}
if bound.UnBounded {
return bound, nil
}
if frameType == ast.Rows {
if bound.Type == ast.CurrentRow {
return bound, nil
}
numRows, _, _ := getUintFromNode(b.ctx, boundClause.Expr)
bound.Num = numRows
return bound, nil
}
bound.CalcFuncs = make([]expression.Expression, len(orderByItems))
bound.CmpFuncs = make([]expression.CompareFunc, len(orderByItems))
if bound.Type == ast.CurrentRow {
for i, item := range orderByItems {
col := item.Col
bound.CalcFuncs[i] = col
bound.CmpFuncs[i] = expression.GetCmpFunction(b.ctx, col, col)
}
return bound, nil
}
col := orderByItems[0].Col
// TODO: We also need to raise error for non-deterministic expressions, like rand().
val, err := evalAstExpr(b.ctx, boundClause.Expr)
if err != nil {
return nil, ErrWindowRangeBoundNotConstant.GenWithStackByArgs(getWindowName(spec.Name.O))
}
expr := expression.Constant{Value: val, RetType: boundClause.Expr.GetType()}
checker := &expression.ParamMarkerInPrepareChecker{}
boundClause.Expr.Accept(checker)
// If it has paramMarker and is in prepare stmt. We don't need to eval it since its value is not decided yet.
if !checker.InPrepareStmt {
// Do not raise warnings for truncate.
oriIgnoreTruncate := b.ctx.GetSessionVars().StmtCtx.IgnoreTruncate
b.ctx.GetSessionVars().StmtCtx.IgnoreTruncate = true
uVal, isNull, err := expr.EvalInt(b.ctx, chunk.Row{})
b.ctx.GetSessionVars().StmtCtx.IgnoreTruncate = oriIgnoreTruncate
if uVal < 0 || isNull || err != nil {
return nil, ErrWindowFrameIllegal.GenWithStackByArgs(getWindowName(spec.Name.O))
}
}
desc := orderByItems[0].Desc
if boundClause.Unit != ast.TimeUnitInvalid {
// TODO: Perhaps we don't need to transcode this back to generic string
unitVal := boundClause.Unit.String()
unit := expression.Constant{
Value: types.NewStringDatum(unitVal),
RetType: types.NewFieldType(mysql.TypeVarchar),
}
// When the order is asc:
// `+` for following, and `-` for the preceding
// When the order is desc, `+` becomes `-` and vice-versa.
funcName := ast.DateAdd
if (!desc && bound.Type == ast.Preceding) || (desc && bound.Type == ast.Following) {
funcName = ast.DateSub
}
bound.CalcFuncs[0], err = expression.NewFunctionBase(b.ctx, funcName, col.RetType, col, &expr, &unit)
if err != nil {
return nil, err
}
bound.CmpFuncs[0] = expression.GetCmpFunction(b.ctx, orderByItems[0].Col, bound.CalcFuncs[0])
return bound, nil
}
// When the order is asc:
// `+` for following, and `-` for the preceding
// When the order is desc, `+` becomes `-` and vice-versa.
funcName := ast.Plus
if (!desc && bound.Type == ast.Preceding) || (desc && bound.Type == ast.Following) {
funcName = ast.Minus
}
bound.CalcFuncs[0], err = expression.NewFunctionBase(b.ctx, funcName, col.RetType, col, &expr)
if err != nil {
return nil, err
}
bound.CmpFuncs[0] = expression.GetCmpFunction(b.ctx, orderByItems[0].Col, bound.CalcFuncs[0])
return bound, nil
}
// buildWindowFunctionFrame builds the window function frames.
// See https://dev.mysql.com/doc/refman/8.0/en/window-functions-frames.html
func (b *PlanBuilder) buildWindowFunctionFrame(ctx context.Context, spec *ast.WindowSpec, orderByItems []property.SortItem) (*WindowFrame, error) {
frameClause := spec.Frame
if frameClause == nil {
return nil, nil
}
frame := &WindowFrame{Type: frameClause.Type}
var err error
frame.Start, err = b.buildWindowFunctionFrameBound(ctx, spec, orderByItems, &frameClause.Extent.Start)
if err != nil {
return nil, err
}
frame.End, err = b.buildWindowFunctionFrameBound(ctx, spec, orderByItems, &frameClause.Extent.End)
return frame, err
}
func (b *PlanBuilder) checkWindowFuncArgs(ctx context.Context, p LogicalPlan, windowFuncExprs []*ast.WindowFuncExpr, windowAggMap map[*ast.AggregateFuncExpr]int) error {
checker := &expression.ParamMarkerInPrepareChecker{}
for _, windowFuncExpr := range windowFuncExprs {
if strings.ToLower(windowFuncExpr.F) == ast.AggFuncGroupConcat {
return ErrNotSupportedYet.GenWithStackByArgs("group_concat as window function")
}
args, err := b.buildArgs4WindowFunc(ctx, p, windowFuncExpr.Args, windowAggMap)
if err != nil {
return err
}
checker.InPrepareStmt = false
for _, expr := range windowFuncExpr.Args {
expr.Accept(checker)
}
desc, err := aggregation.NewWindowFuncDesc(b.ctx, windowFuncExpr.F, args, checker.InPrepareStmt)
if err != nil {
return err
}
if desc == nil {
return ErrWrongArguments.GenWithStackByArgs(strings.ToLower(windowFuncExpr.F))
}
}
return nil
}
func getAllByItems(itemsBuf []*ast.ByItem, spec *ast.WindowSpec) []*ast.ByItem {
itemsBuf = itemsBuf[:0]
if spec.PartitionBy != nil {
itemsBuf = append(itemsBuf, spec.PartitionBy.Items...)
}
if spec.OrderBy != nil {
itemsBuf = append(itemsBuf, spec.OrderBy.Items...)
}
return itemsBuf
}
func restoreByItemText(item *ast.ByItem) string {
var sb strings.Builder
ctx := format.NewRestoreCtx(0, &sb)
err := item.Expr.Restore(ctx)
if err != nil {
return ""
}
return sb.String()
}
func compareItems(lItems []*ast.ByItem, rItems []*ast.ByItem) bool {
minLen := mathutil.Min(len(lItems), len(rItems))
for i := 0; i < minLen; i++ {
res := strings.Compare(restoreByItemText(lItems[i]), restoreByItemText(rItems[i]))
if res != 0 {
return res < 0
}
res = compareBool(lItems[i].Desc, rItems[i].Desc)
if res != 0 {
return res < 0
}
}
return len(lItems) < len(rItems)
}
type windowFuncs struct {
spec *ast.WindowSpec
funcs []*ast.WindowFuncExpr
}
// sortWindowSpecs sorts the window specifications by reversed alphabetical order, then we could add less `Sort` operator
// in physical plan because the window functions with the same partition by and order by clause will be at near places.
func sortWindowSpecs(groupedFuncs map[*ast.WindowSpec][]*ast.WindowFuncExpr, orderedSpec []*ast.WindowSpec) []windowFuncs {
windows := make([]windowFuncs, 0, len(groupedFuncs))
for _, spec := range orderedSpec {
windows = append(windows, windowFuncs{spec, groupedFuncs[spec]})
}
lItemsBuf := make([]*ast.ByItem, 0, 4)
rItemsBuf := make([]*ast.ByItem, 0, 4)
sort.SliceStable(windows, func(i, j int) bool {
lItemsBuf = getAllByItems(lItemsBuf, windows[i].spec)
rItemsBuf = getAllByItems(rItemsBuf, windows[j].spec)
return !compareItems(lItemsBuf, rItemsBuf)
})
return windows
}
func (b *PlanBuilder) buildWindowFunctions(ctx context.Context, p LogicalPlan, groupedFuncs map[*ast.WindowSpec][]*ast.WindowFuncExpr, orderedSpec []*ast.WindowSpec, aggMap map[*ast.AggregateFuncExpr]int) (LogicalPlan, map[*ast.WindowFuncExpr]int, error) {
args := make([]ast.ExprNode, 0, 4)
windowMap := make(map[*ast.WindowFuncExpr]int)
for _, window := range sortWindowSpecs(groupedFuncs, orderedSpec) {
args = args[:0]
spec, funcs := window.spec, window.funcs
for _, windowFunc := range funcs {
args = append(args, windowFunc.Args...)
}
np, partitionBy, orderBy, args, err := b.buildProjectionForWindow(ctx, p, spec, args, aggMap)
if err != nil {
return nil, nil, err
}
if len(funcs) == 0 {
// len(funcs) == 0 indicates this an unused named window spec,
// so we just check for its validity and don't have to build plan for it.
err := b.checkOriginWindowSpec(spec, orderBy)
if err != nil {
return nil, nil, err
}
continue
}
err = b.checkOriginWindowFuncs(funcs, orderBy)
if err != nil {
return nil, nil, err
}
frame, err := b.buildWindowFunctionFrame(ctx, spec, orderBy)
if err != nil {
return nil, nil, err
}
window := LogicalWindow{
PartitionBy: partitionBy,
OrderBy: orderBy,
Frame: frame,
}.Init(b.ctx, b.getSelectOffset())
window.names = make([]*types.FieldName, np.Schema().Len())
copy(window.names, np.OutputNames())
schema := np.Schema().Clone()
descs := make([]*aggregation.WindowFuncDesc, 0, len(funcs))
preArgs := 0
checker := &expression.ParamMarkerInPrepareChecker{}
for _, windowFunc := range funcs {
checker.InPrepareStmt = false
for _, expr := range windowFunc.Args {
expr.Accept(checker)
}
desc, err := aggregation.NewWindowFuncDesc(b.ctx, windowFunc.F, args[preArgs:preArgs+len(windowFunc.Args)], checker.InPrepareStmt)
if err != nil {
return nil, nil, err
}
if desc == nil {
return nil, nil, ErrWrongArguments.GenWithStackByArgs(strings.ToLower(windowFunc.F))
}
preArgs += len(windowFunc.Args)
desc.WrapCastForAggArgs(b.ctx)
descs = append(descs, desc)
windowMap[windowFunc] = schema.Len()
schema.Append(&expression.Column{
UniqueID: b.ctx.GetSessionVars().AllocPlanColumnID(),
RetType: desc.RetTp,
})
window.names = append(window.names, types.EmptyName)
}
window.WindowFuncDescs = descs
window.SetChildren(np)
window.SetSchema(schema)
p = window
}
return p, windowMap, nil
}
// checkOriginWindowFuncs checks the validity for original window specifications for a group of functions.
// Because the grouped specification is different from them, we should especially check them before build window frame.
func (b *PlanBuilder) checkOriginWindowFuncs(funcs []*ast.WindowFuncExpr, orderByItems []property.SortItem) error {
for _, f := range funcs {
if f.IgnoreNull {
return ErrNotSupportedYet.GenWithStackByArgs("IGNORE NULLS")
}
if f.Distinct {
return ErrNotSupportedYet.GenWithStackByArgs("<window function>(DISTINCT ..)")
}
if f.FromLast {
return ErrNotSupportedYet.GenWithStackByArgs("FROM LAST")
}
spec := &f.Spec
if f.Spec.Name.L != "" {
spec = b.windowSpecs[f.Spec.Name.L]
}
if err := b.checkOriginWindowSpec(spec, orderByItems); err != nil {
return err
}
}
return nil
}
// checkOriginWindowSpec checks the validity for given window specification.
func (b *PlanBuilder) checkOriginWindowSpec(spec *ast.WindowSpec, orderByItems []property.SortItem) error {
if spec.Frame == nil {
return nil
}
if spec.Frame.Type == ast.Groups {
return ErrNotSupportedYet.GenWithStackByArgs("GROUPS")
}
start, end := spec.Frame.Extent.Start, spec.Frame.Extent.End
if start.Type == ast.Following && start.UnBounded {
return ErrWindowFrameStartIllegal.GenWithStackByArgs(getWindowName(spec.Name.O))
}
if end.Type == ast.Preceding && end.UnBounded {
return ErrWindowFrameEndIllegal.GenWithStackByArgs(getWindowName(spec.Name.O))
}
if start.Type == ast.Following && (end.Type == ast.Preceding || end.Type == ast.CurrentRow) {
return ErrWindowFrameIllegal.GenWithStackByArgs(getWindowName(spec.Name.O))
}
if (start.Type == ast.Following || start.Type == ast.CurrentRow) && end.Type == ast.Preceding {
return ErrWindowFrameIllegal.GenWithStackByArgs(getWindowName(spec.Name.O))
}
err := b.checkOriginWindowFrameBound(&start, spec, orderByItems)
if err != nil {
return err
}
err = b.checkOriginWindowFrameBound(&end, spec, orderByItems)
if err != nil {
return err
}
return nil
}
func (b *PlanBuilder) checkOriginWindowFrameBound(bound *ast.FrameBound, spec *ast.WindowSpec, orderByItems []property.SortItem) error {
if bound.Type == ast.CurrentRow || bound.UnBounded {
return nil
}
frameType := spec.Frame.Type
if frameType == ast.Rows {
if bound.Unit != ast.TimeUnitInvalid {
return ErrWindowRowsIntervalUse.GenWithStackByArgs(getWindowName(spec.Name.O))
}
_, isNull, isExpectedType := getUintFromNode(b.ctx, bound.Expr)
if isNull || !isExpectedType {
return ErrWindowFrameIllegal.GenWithStackByArgs(getWindowName(spec.Name.O))
}
return nil
}
if len(orderByItems) != 1 {
return ErrWindowRangeFrameOrderType.GenWithStackByArgs(getWindowName(spec.Name.O))
}
orderItemType := orderByItems[0].Col.RetType.GetType()
isNumeric, isTemporal := types.IsTypeNumeric(orderItemType), types.IsTypeTemporal(orderItemType)
if !isNumeric && !isTemporal {
return ErrWindowRangeFrameOrderType.GenWithStackByArgs(getWindowName(spec.Name.O))
}
if bound.Unit != ast.TimeUnitInvalid && !isTemporal {
return ErrWindowRangeFrameNumericType.GenWithStackByArgs(getWindowName(spec.Name.O))
}
if bound.Unit == ast.TimeUnitInvalid && !isNumeric {
return ErrWindowRangeFrameTemporalType.GenWithStackByArgs(getWindowName(spec.Name.O))
}
return nil
}
func extractWindowFuncs(fields []*ast.SelectField) []*ast.WindowFuncExpr {
extractor := &WindowFuncExtractor{}
for _, f := range fields {
n, _ := f.Expr.Accept(extractor)
f.Expr = n.(ast.ExprNode)
}
return extractor.windowFuncs
}
func (b *PlanBuilder) handleDefaultFrame(spec *ast.WindowSpec, windowFuncName string) (*ast.WindowSpec, bool) {
needFrame := aggregation.NeedFrame(windowFuncName)
// According to MySQL, In the absence of a frame clause, the default frame depends on whether an ORDER BY clause is present:
// (1) With order by, the default frame is equivalent to "RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW";
// (2) Without order by, the default frame is includes all partition rows, equivalent to "RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING",
// or "ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING", which is the same as an empty frame.
// https://dev.mysql.com/doc/refman/8.0/en/window-functions-frames.html
if needFrame && spec.Frame == nil && spec.OrderBy != nil {
newSpec := *spec
newSpec.Frame = &ast.FrameClause{
Type: ast.Ranges,
Extent: ast.FrameExtent{
Start: ast.FrameBound{Type: ast.Preceding, UnBounded: true},
End: ast.FrameBound{Type: ast.CurrentRow},
},
}
return &newSpec, true
}
// "RANGE/ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING" is equivalent to empty frame.
if needFrame && spec.Frame != nil &&
spec.Frame.Extent.Start.UnBounded && spec.Frame.Extent.End.UnBounded {
newSpec := *spec
newSpec.Frame = nil
return &newSpec, true
}
if !needFrame {
var updated bool
newSpec := *spec
// For functions that operate on the entire partition, the frame clause will be ignored.
if spec.Frame != nil {
specName := spec.Name.O
b.ctx.GetSessionVars().StmtCtx.AppendNote(ErrWindowFunctionIgnoresFrame.GenWithStackByArgs(windowFuncName, getWindowName(specName)))
newSpec.Frame = nil
updated = true
}
if b.ctx.GetSessionVars().EnablePipelinedWindowExec {
useDefaultFrame, defaultFrame := aggregation.UseDefaultFrame(windowFuncName)
if useDefaultFrame {
newSpec.Frame = &defaultFrame
updated = true
}
}
if updated {
return &newSpec, true
}
}
return spec, false
}
// append ast.WindowSpec to []*ast.WindowSpec if absent
func appendIfAbsentWindowSpec(specs []*ast.WindowSpec, ns *ast.WindowSpec) []*ast.WindowSpec {
for _, spec := range specs {
if spec == ns {
return specs
}
}
return append(specs, ns)
}
func specEqual(s1, s2 *ast.WindowSpec) (equal bool, err error) {
if (s1 == nil && s2 != nil) || (s1 != nil && s2 == nil) {
return false, nil
}
var sb1, sb2 strings.Builder
ctx1 := format.NewRestoreCtx(0, &sb1)
ctx2 := format.NewRestoreCtx(0, &sb2)
if err = s1.Restore(ctx1); err != nil {
return
}
if err = s2.Restore(ctx2); err != nil {
return
}
return sb1.String() == sb2.String(), nil
}
// groupWindowFuncs groups the window functions according to the window specification name.
// TODO: We can group the window function by the definition of window specification.
func (b *PlanBuilder) groupWindowFuncs(windowFuncs []*ast.WindowFuncExpr) (map[*ast.WindowSpec][]*ast.WindowFuncExpr, []*ast.WindowSpec, error) {
// updatedSpecMap is used to handle the specifications that have frame clause changed.
updatedSpecMap := make(map[string][]*ast.WindowSpec)
groupedWindow := make(map[*ast.WindowSpec][]*ast.WindowFuncExpr)
orderedSpec := make([]*ast.WindowSpec, 0, len(windowFuncs))
for _, windowFunc := range windowFuncs {
if windowFunc.Spec.Name.L == "" {
spec := &windowFunc.Spec
if spec.Ref.L != "" {
ref, ok := b.windowSpecs[spec.Ref.L]
if !ok {
return nil, nil, ErrWindowNoSuchWindow.GenWithStackByArgs(getWindowName(spec.Ref.O))
}
err := mergeWindowSpec(spec, ref)
if err != nil {
return nil, nil, err
}
}
spec, _ = b.handleDefaultFrame(spec, windowFunc.F)
groupedWindow[spec] = append(groupedWindow[spec], windowFunc)
orderedSpec = appendIfAbsentWindowSpec(orderedSpec, spec)
continue
}
name := windowFunc.Spec.Name.L
spec, ok := b.windowSpecs[name]
if !ok {
return nil, nil, ErrWindowNoSuchWindow.GenWithStackByArgs(windowFunc.Spec.Name.O)
}
newSpec, updated := b.handleDefaultFrame(spec, windowFunc.F)
if !updated {
groupedWindow[spec] = append(groupedWindow[spec], windowFunc)
orderedSpec = appendIfAbsentWindowSpec(orderedSpec, spec)
} else {
var updatedSpec *ast.WindowSpec
if _, ok := updatedSpecMap[name]; !ok {
updatedSpecMap[name] = []*ast.WindowSpec{newSpec}
updatedSpec = newSpec
} else {
for _, spec := range updatedSpecMap[name] {
eq, err := specEqual(spec, newSpec)
if err != nil {
return nil, nil, err
}
if eq {
updatedSpec = spec
break
}
}
if updatedSpec == nil {
updatedSpec = newSpec
updatedSpecMap[name] = append(updatedSpecMap[name], newSpec)
}
}
groupedWindow[updatedSpec] = append(groupedWindow[updatedSpec], windowFunc)
orderedSpec = appendIfAbsentWindowSpec(orderedSpec, updatedSpec)
}
}
// Unused window specs should also be checked in b.buildWindowFunctions,
// so we add them to `groupedWindow` with empty window functions.
for _, spec := range b.windowSpecs {
if _, ok := groupedWindow[spec]; !ok {
if _, ok = updatedSpecMap[spec.Name.L]; !ok {
groupedWindow[spec] = nil
orderedSpec = appendIfAbsentWindowSpec(orderedSpec, spec)
}
}
}
return groupedWindow, orderedSpec, nil
}
// resolveWindowSpec resolve window specifications for sql like `select ... from t window w1 as (w2), w2 as (partition by a)`.
// We need to resolve the referenced window to get the definition of current window spec.
func resolveWindowSpec(spec *ast.WindowSpec, specs map[string]*ast.WindowSpec, inStack map[string]bool) error {
if inStack[spec.Name.L] {
return errors.Trace(ErrWindowCircularityInWindowGraph)
}
if spec.Ref.L == "" {
return nil
}
ref, ok := specs[spec.Ref.L]
if !ok {
return ErrWindowNoSuchWindow.GenWithStackByArgs(spec.Ref.O)
}
inStack[spec.Name.L] = true
err := resolveWindowSpec(ref, specs, inStack)
if err != nil {
return err
}
inStack[spec.Name.L] = false
return mergeWindowSpec(spec, ref)
}
func mergeWindowSpec(spec, ref *ast.WindowSpec) error {
if ref.Frame != nil {
return ErrWindowNoInherentFrame.GenWithStackByArgs(ref.Name.O)
}
if spec.PartitionBy != nil {
return errors.Trace(ErrWindowNoChildPartitioning)
}
if ref.OrderBy != nil {
if spec.OrderBy != nil {
return ErrWindowNoRedefineOrderBy.GenWithStackByArgs(getWindowName(spec.Name.O), ref.Name.O)
}
spec.OrderBy = ref.OrderBy
}
spec.PartitionBy = ref.PartitionBy
spec.Ref = model.NewCIStr("")
return nil
}
func buildWindowSpecs(specs []ast.WindowSpec) (map[string]*ast.WindowSpec, error) {
specsMap := make(map[string]*ast.WindowSpec, len(specs))
for _, spec := range specs {
if _, ok := specsMap[spec.Name.L]; ok {
return nil, ErrWindowDuplicateName.GenWithStackByArgs(spec.Name.O)
}
newSpec := spec
specsMap[spec.Name.L] = &newSpec
}
inStack := make(map[string]bool, len(specs))
for _, spec := range specsMap {
err := resolveWindowSpec(spec, specsMap, inStack)
if err != nil {
return nil, err
}
}
return specsMap, nil
}
func unfoldSelectList(list *ast.SetOprSelectList, unfoldList *ast.SetOprSelectList) {
for _, sel := range list.Selects {
switch s := sel.(type) {
case *ast.SelectStmt:
unfoldList.Selects = append(unfoldList.Selects, s)
case *ast.SetOprSelectList:
unfoldSelectList(s, unfoldList)
}
}
}
type updatableTableListResolver struct {
updatableTableList []*ast.TableName
}
func (u *updatableTableListResolver) Enter(inNode ast.Node) (ast.Node, bool) {
switch v := inNode.(type) {
case *ast.UpdateStmt, *ast.TableRefsClause, *ast.Join, *ast.TableSource, *ast.TableName:
return v, false
}
return inNode, true
}
func (u *updatableTableListResolver) Leave(inNode ast.Node) (ast.Node, bool) {
if v, ok := inNode.(*ast.TableSource); ok {
if s, ok := v.Source.(*ast.TableName); ok {
if v.AsName.L != "" {
newTableName := *s
newTableName.Name = v.AsName
newTableName.Schema = model.NewCIStr("")
u.updatableTableList = append(u.updatableTableList, &newTableName)
} else {
u.updatableTableList = append(u.updatableTableList, s)
}
}
}
return inNode, true
}
// extractTableList extracts all the TableNames from node.
// If asName is true, extract AsName prior to OrigName.
// Privilege check should use OrigName, while expression may use AsName.
// TODO: extracting all tables by vistor model maybe a better way
func extractTableList(node ast.Node, input []*ast.TableName, asName bool) []*ast.TableName {
switch x := node.(type) {
case *ast.SelectStmt:
if x.From != nil {
input = extractTableList(x.From.TableRefs, input, asName)
}
if x.Where != nil {
input = extractTableList(x.Where, input, asName)
}
if x.With != nil {
for _, cte := range x.With.CTEs {
input = extractTableList(cte.Query, input, asName)
}
}
for _, f := range x.Fields.Fields {
if s, ok := f.Expr.(*ast.SubqueryExpr); ok {
input = extractTableList(s, input, asName)
}
}
case *ast.DeleteStmt:
input = extractTableList(x.TableRefs.TableRefs, input, asName)
if x.IsMultiTable {
for _, t := range x.Tables.Tables {
input = extractTableList(t, input, asName)
}
}
if x.Where != nil {
input = extractTableList(x.Where, input, asName)
}
if x.With != nil {
for _, cte := range x.With.CTEs {
input = extractTableList(cte.Query, input, asName)
}
}
case *ast.UpdateStmt:
input = extractTableList(x.TableRefs.TableRefs, input, asName)
for _, e := range x.List {
input = extractTableList(e.Expr, input, asName)
}
if x.Where != nil {
input = extractTableList(x.Where, input, asName)
}
if x.With != nil {
for _, cte := range x.With.CTEs {
input = extractTableList(cte.Query, input, asName)
}
}
case *ast.InsertStmt:
input = extractTableList(x.Table.TableRefs, input, asName)
input = extractTableList(x.Select, input, asName)
case *ast.SetOprStmt:
l := &ast.SetOprSelectList{}
unfoldSelectList(x.SelectList, l)
for _, s := range l.Selects {
input = extractTableList(s.(ast.ResultSetNode), input, asName)
}
case *ast.PatternInExpr:
if s, ok := x.Sel.(*ast.SubqueryExpr); ok {
input = extractTableList(s, input, asName)
}
case *ast.ExistsSubqueryExpr:
if s, ok := x.Sel.(*ast.SubqueryExpr); ok {
input = extractTableList(s, input, asName)
}
case *ast.BinaryOperationExpr:
if s, ok := x.R.(*ast.SubqueryExpr); ok {
input = extractTableList(s, input, asName)
}
case *ast.SubqueryExpr:
input = extractTableList(x.Query, input, asName)
case *ast.Join:
input = extractTableList(x.Left, input, asName)
input = extractTableList(x.Right, input, asName)
case *ast.TableSource:
if s, ok := x.Source.(*ast.TableName); ok {
if x.AsName.L != "" && asName {
newTableName := *s
newTableName.Name = x.AsName
newTableName.Schema = model.NewCIStr("")
input = append(input, &newTableName)
} else {
input = append(input, s)
}
} else if s, ok := x.Source.(*ast.SelectStmt); ok {
if s.From != nil {
var innerList []*ast.TableName
innerList = extractTableList(s.From.TableRefs, innerList, asName)
if len(innerList) > 0 {
innerTableName := innerList[0]
if x.AsName.L != "" && asName {
newTableName := *innerList[0]
newTableName.Name = x.AsName
newTableName.Schema = model.NewCIStr("")
innerTableName = &newTableName
}
input = append(input, innerTableName)
}
}
}
}
return input
}
func collectTableName(node ast.ResultSetNode, updatableName *map[string]bool, info *map[string]*ast.TableName) {
switch x := node.(type) {
case *ast.Join:
collectTableName(x.Left, updatableName, info)
collectTableName(x.Right, updatableName, info)
case *ast.TableSource:
name := x.AsName.L
var canUpdate bool
var s *ast.TableName
if s, canUpdate = x.Source.(*ast.TableName); canUpdate {
if name == "" {
name = s.Schema.L + "." + s.Name.L
// it may be a CTE
if s.Schema.L == "" {
name = s.Name.L
}
}
(*info)[name] = s
}
(*updatableName)[name] = canUpdate && s.Schema.L != ""
}
}
func appendDynamicVisitInfo(vi []visitInfo, priv string, withGrant bool, err error) []visitInfo {
return append(vi, visitInfo{
privilege: mysql.ExtendedPriv,
dynamicPriv: priv,
dynamicWithGrant: withGrant,
err: err,
})
}
func appendVisitInfo(vi []visitInfo, priv mysql.PrivilegeType, db, tbl, col string, err error) []visitInfo {
return append(vi, visitInfo{
privilege: priv,
db: db,
table: tbl,
column: col,
err: err,
})
}
func getInnerFromParenthesesAndUnaryPlus(expr ast.ExprNode) ast.ExprNode {
if pexpr, ok := expr.(*ast.ParenthesesExpr); ok {
return getInnerFromParenthesesAndUnaryPlus(pexpr.Expr)
}
if uexpr, ok := expr.(*ast.UnaryOperationExpr); ok && uexpr.Op == opcode.Plus {
return getInnerFromParenthesesAndUnaryPlus(uexpr.V)
}
return expr
}
// containDifferentJoinTypes checks whether `preferJoinType` contains different
// join types.
func containDifferentJoinTypes(preferJoinType uint) bool {
inlMask := preferRightAsINLJInner ^ preferLeftAsINLJInner
inlhjMask := preferRightAsINLHJInner ^ preferLeftAsINLHJInner
inlmjMask := preferRightAsINLMJInner ^ preferLeftAsINLMJInner
hjRightBuildMask := preferRightAsHJBuild ^ preferLeftAsHJProbe
hjLeftBuildMask := preferLeftAsHJBuild ^ preferRightAsHJProbe
mask := inlMask ^ inlhjMask ^ inlmjMask ^ hjRightBuildMask ^ hjLeftBuildMask
onesCount := bits.OnesCount(preferJoinType & ^mask)
if onesCount > 1 || onesCount == 1 && preferJoinType&mask > 0 {
return true
}
cnt := 0
if preferJoinType&inlMask > 0 {
cnt++
}
if preferJoinType&inlhjMask > 0 {
cnt++
}
if preferJoinType&inlmjMask > 0 {
cnt++
}
if preferJoinType&hjLeftBuildMask > 0 {
cnt++
}
if preferJoinType&hjRightBuildMask > 0 {
cnt++
}
return cnt > 1
}
func (b *PlanBuilder) buildCte(ctx context.Context, cte *ast.CommonTableExpression, isRecursive bool) (p LogicalPlan, err error) {
saveBuildingCTE := b.buildingCTE
b.buildingCTE = true
defer func() {
b.buildingCTE = saveBuildingCTE
}()
if isRecursive {
// buildingRecursivePartForCTE likes a stack. We save it before building a recursive CTE and restore it after building.
// We need a stack because we need to handle the nested recursive CTE. And buildingRecursivePartForCTE indicates the innermost CTE.
saveCheck := b.buildingRecursivePartForCTE
b.buildingRecursivePartForCTE = false
err = b.buildRecursiveCTE(ctx, cte.Query.Query)
if err != nil {
return nil, err
}
b.buildingRecursivePartForCTE = saveCheck
} else {
p, err = b.buildResultSetNode(ctx, cte.Query.Query, true)
if err != nil {
return nil, err
}
p, err = b.adjustCTEPlanOutputName(p, cte)
if err != nil {
return nil, err
}
cInfo := b.outerCTEs[len(b.outerCTEs)-1]
cInfo.seedLP = p
}
return nil, nil
}
// buildRecursiveCTE handles the with clause `with recursive xxx as xx`.
func (b *PlanBuilder) buildRecursiveCTE(ctx context.Context, cte ast.ResultSetNode) error {
b.isCTE = true
cInfo := b.outerCTEs[len(b.outerCTEs)-1]
switch x := (cte).(type) {
case *ast.SetOprStmt:
// 1. Handle the WITH clause if exists.
if x.With != nil {
l := len(b.outerCTEs)
defer func() {
b.outerCTEs = b.outerCTEs[:l]
sw := x.With
x.With = sw
}()
err := b.buildWith(ctx, x.With)
if err != nil {
return err
}
}
// Set it to nil, so that when builds the seed part, it won't build again. Reset it in defer so that the AST doesn't change after this function.
x.With = nil
// 2. Build plans for each part of SetOprStmt.
recursive := make([]LogicalPlan, 0)
tmpAfterSetOptsForRecur := []*ast.SetOprType{nil}
expectSeed := true
for i := 0; i < len(x.SelectList.Selects); i++ {
var p LogicalPlan
var err error
var afterOpr *ast.SetOprType
switch y := x.SelectList.Selects[i].(type) {
case *ast.SelectStmt:
p, err = b.buildSelect(ctx, y)
afterOpr = y.AfterSetOperator
case *ast.SetOprSelectList:
p, err = b.buildSetOpr(ctx, &ast.SetOprStmt{SelectList: y, With: y.With})
afterOpr = y.AfterSetOperator
}
if expectSeed {
if cInfo.useRecursive {
// 3. If it fail to build a plan, it may be the recursive part. Then we build the seed part plan, and rebuild it.
if i == 0 {
return ErrCTERecursiveRequiresNonRecursiveFirst.GenWithStackByArgs(cInfo.def.Name.String())
}
// It's the recursive part. Build the seed part, and build this recursive part again.
// Before we build the seed part, do some checks.
if x.OrderBy != nil {
return ErrNotSupportedYet.GenWithStackByArgs("ORDER BY over UNION in recursive Common Table Expression")
}
// Limit clause is for the whole CTE instead of only for the seed part.
oriLimit := x.Limit
x.Limit = nil
// Check union type.
if afterOpr != nil {
if *afterOpr != ast.Union && *afterOpr != ast.UnionAll {
return ErrNotSupportedYet.GenWithStackByArgs(fmt.Sprintf("%s between seed part and recursive part, hint: The operator between seed part and recursive part must bu UNION[DISTINCT] or UNION ALL", afterOpr.String()))
}
cInfo.isDistinct = *afterOpr == ast.Union
}
expectSeed = false
cInfo.useRecursive = false
// Build seed part plan.
saveSelect := x.SelectList.Selects
x.SelectList.Selects = x.SelectList.Selects[:i]
p, err = b.buildSetOpr(ctx, x)
if err != nil {
return err
}
x.SelectList.Selects = saveSelect
p, err = b.adjustCTEPlanOutputName(p, cInfo.def)
if err != nil {
return err
}
cInfo.seedLP = p
// Rebuild the plan.
i--
b.buildingRecursivePartForCTE = true
x.Limit = oriLimit
continue
}
if err != nil {
return err
}
} else {
if err != nil {
return err
}
if afterOpr != nil {
if *afterOpr != ast.Union && *afterOpr != ast.UnionAll {
return ErrNotSupportedYet.GenWithStackByArgs(fmt.Sprintf("%s between recursive part's selects, hint: The operator between recursive part's selects must bu UNION[DISTINCT] or UNION ALL", afterOpr.String()))
}
}
if !cInfo.useRecursive {
return ErrCTERecursiveRequiresNonRecursiveFirst.GenWithStackByArgs(cInfo.def.Name.String())
}
cInfo.useRecursive = false
recursive = append(recursive, p)
tmpAfterSetOptsForRecur = append(tmpAfterSetOptsForRecur, afterOpr)
}
}
if len(recursive) == 0 {
// In this case, even if SQL specifies "WITH RECURSIVE", the CTE is non-recursive.
p, err := b.buildSetOpr(ctx, x)
if err != nil {
return err
}
p, err = b.adjustCTEPlanOutputName(p, cInfo.def)
if err != nil {
return err
}
cInfo.seedLP = p
return nil
}
// Build the recursive part's logical plan.
recurPart, err := b.buildUnion(ctx, recursive, tmpAfterSetOptsForRecur)
if err != nil {
return err
}
recurPart, err = b.buildProjection4CTEUnion(ctx, cInfo.seedLP, recurPart)
if err != nil {
return err
}
// 4. Finally, we get the seed part plan and recursive part plan.
cInfo.recurLP = recurPart
// Only need to handle limit if x is SetOprStmt.
if x.Limit != nil {
limit, err := b.buildLimit(cInfo.seedLP, x.Limit)
if err != nil {
return err
}
limit.SetChildren(limit.Children()[:0]...)
cInfo.limitLP = limit
}
return nil
default:
p, err := b.buildResultSetNode(ctx, x, true)
if err != nil {
// Refine the error message.
if errors.ErrorEqual(err, ErrCTERecursiveRequiresNonRecursiveFirst) {
err = ErrCTERecursiveRequiresUnion.GenWithStackByArgs(cInfo.def.Name.String())
}
return err
}
p, err = b.adjustCTEPlanOutputName(p, cInfo.def)
if err != nil {
return err
}
cInfo.seedLP = p
return nil
}
}
func (b *PlanBuilder) adjustCTEPlanOutputName(p LogicalPlan, def *ast.CommonTableExpression) (LogicalPlan, error) {
outPutNames := p.OutputNames()
for _, name := range outPutNames {
name.TblName = def.Name
name.DBName = model.NewCIStr(b.ctx.GetSessionVars().CurrentDB)
}
if len(def.ColNameList) > 0 {
if len(def.ColNameList) != len(p.OutputNames()) {
return nil, dbterror.ErrViewWrongList
}
for i, n := range def.ColNameList {
outPutNames[i].ColName = n
}
}
p.SetOutputNames(outPutNames)
return p, nil
}
// prepareCTECheckForSubQuery prepares the check that the recursive CTE can't be referenced in subQuery. It's used before building a subQuery.
// For example: with recursive cte(n) as (select 1 union select * from (select * from cte) c1) select * from cte;
func (b *PlanBuilder) prepareCTECheckForSubQuery() []*cteInfo {
modifiedCTE := make([]*cteInfo, 0)
for _, cte := range b.outerCTEs {
if cte.isBuilding && !cte.enterSubquery {
cte.enterSubquery = true
modifiedCTE = append(modifiedCTE, cte)
}
}
return modifiedCTE
}
// resetCTECheckForSubQuery resets the related variable. It's used after leaving a subQuery.
func resetCTECheckForSubQuery(ci []*cteInfo) {
for _, cte := range ci {
cte.enterSubquery = false
}
}
// genCTETableNameForError find the nearest CTE name.
func (b *PlanBuilder) genCTETableNameForError() string {
name := ""
for i := len(b.outerCTEs) - 1; i >= 0; i-- {
if b.outerCTEs[i].isBuilding {
name = b.outerCTEs[i].def.Name.String()
break
}
}
return name
}
func (b *PlanBuilder) buildWith(ctx context.Context, w *ast.WithClause) error {
// Check CTE name must be unique.
nameMap := make(map[string]struct{})
for _, cte := range w.CTEs {
if _, ok := nameMap[cte.Name.L]; ok {
return ErrNonUniqTable
}
nameMap[cte.Name.L] = struct{}{}
}
for _, cte := range w.CTEs {
b.outerCTEs = append(b.outerCTEs, &cteInfo{def: cte, nonRecursive: !w.IsRecursive, isBuilding: true, storageID: b.allocIDForCTEStorage, seedStat: &property.StatsInfo{}})
b.allocIDForCTEStorage++
saveFlag := b.optFlag
// Init the flag to flagPrunColumns, otherwise it's missing.
b.optFlag = flagPrunColumns
_, err := b.buildCte(ctx, cte, w.IsRecursive)
if err != nil {
return err
}
b.outerCTEs[len(b.outerCTEs)-1].optFlag = b.optFlag
b.outerCTEs[len(b.outerCTEs)-1].isBuilding = false
b.optFlag = saveFlag
// each cte (select statement) will generate a handle map, pop it out here.
b.handleHelper.popMap()
}
return nil
}
func (b *PlanBuilder) buildProjection4CTEUnion(_ context.Context, seed LogicalPlan, recur LogicalPlan) (LogicalPlan, error) {
if seed.Schema().Len() != recur.Schema().Len() {
return nil, ErrWrongNumberOfColumnsInSelect.GenWithStackByArgs()
}
exprs := make([]expression.Expression, len(seed.Schema().Columns))
resSchema := getResultCTESchema(seed.Schema(), b.ctx.GetSessionVars())
for i, col := range recur.Schema().Columns {
if !resSchema.Columns[i].RetType.Equal(col.RetType) {
exprs[i] = expression.BuildCastFunction4Union(b.ctx, col, resSchema.Columns[i].RetType)
} else {
exprs[i] = col
}
}
b.optFlag |= flagEliminateProjection
proj := LogicalProjection{Exprs: exprs, AvoidColumnEvaluator: true}.Init(b.ctx, b.getSelectOffset())
proj.SetSchema(resSchema)
proj.SetChildren(recur)
return proj, nil
}
// The recursive part/CTE's schema is nullable, and the UID should be unique.
func getResultCTESchema(seedSchema *expression.Schema, svar *variable.SessionVars) *expression.Schema {
res := seedSchema.Clone()
for _, col := range res.Columns {
col.RetType = col.RetType.Clone()
col.UniqueID = svar.AllocPlanColumnID()
col.RetType.DelFlag(mysql.NotNullFlag)
// Since you have reallocated unique id here, the old-cloned-cached hash code is not valid anymore.
col.CleanHashCode()
}
return res
}
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