tidb advisor 代码
文件路径：/parser/ast/advisor.go
/ Copyright 2019 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,
/ See the License for the specific language governing permissions and
/ limitations under the License.
package ast
import (
"github.com/pingcap/tidb/parser/format"
)
var _ StmtNode = &IndexAdviseStmt{}
/ IndexAdviseStmt is used to advise indexes
type IndexAdviseStmt struct {
stmtNode
IsLocal bool
Path string
MaxMinutes uint64
MaxIndexNum *MaxIndexNumClause
LinesInfo *LinesClause
}
/ Restore implements Node Accept interface.
func (n *IndexAdviseStmt) Restore(ctx *format.RestoreCtx) error {
ctx.WriteKeyWord("INDEX ADVISE ")
if n.IsLocal {
ctx.WriteKeyWord("LOCAL ")
}
ctx.WriteKeyWord("INFILE ")
ctx.WriteString(n.Path)
if n.MaxMinutes != UnspecifiedSize {
ctx.WriteKeyWord(" MAX_MINUTES ")
ctx.WritePlainf("%d", n.MaxMinutes)
}
if n.MaxIndexNum != nil {
n.MaxIndexNum.Restore(ctx)
}
n.LinesInfo.Restore(ctx)
return nil
}
/ Accept implements Node Accept interface.
func (n *IndexAdviseStmt) Accept(v Visitor) (Node, bool) {
newNode, skipChildren := v.Enter(n)
if skipChildren {
return v.Leave(newNode)
}
n = newNode.(*IndexAdviseStmt)
return v.Leave(n)
}
/ MaxIndexNumClause represents 'maximum number of indexes' clause in index advise statement.
type MaxIndexNumClause struct {
PerTable uint64
PerDB uint64
}
/ Restore for max index num clause
func (n *MaxIndexNumClause) Restore(ctx *format.RestoreCtx) error {
ctx.WriteKeyWord(" MAX_IDXNUM")
if n.PerTable != UnspecifiedSize {
ctx.WriteKeyWord(" PER_TABLE ")
ctx.WritePlainf("%d", n.PerTable)
}
if n.PerDB != UnspecifiedSize {
ctx.WriteKeyWord(" PER_DB ")
ctx.WritePlainf("%d", n.PerDB)
}
return nil
}