greenplumn CQueryMutators 代码
文件路径：/src/include/gpopt/translate/CQueryMutators.h
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2012 EMC Corp.
/
/ @filename:
/ CQueryMutators.h
/
/ @doc:
/ Class providing methods for translating a GPDB Query object into a
/ DXL Tree
/
/ @test:
/
/
/---------------------------------------------------------------------------
#ifndef GPDXL_CWalkerUtils_H
#define GPDXL_CWalkerUtils_H
#include "gpos/base.h"
#include "gpopt/translate/CMappingVarColId.h"
#include "gpopt/translate/CTranslatorScalarToDXL.h"
#include "gpopt/translate/CTranslatorUtils.h"
#include "naucrates/dxl/operators/CDXLNode.h"
#include "naucrates/md/IMDType.h"
/ fwd declarations
namespace gpopt
{
class CMDAccessor;
}
struct Query;
struct RangeTblEntry;
struct Const;
struct List;
namespace gpdxl
{
/---------------------------------------------------------------------------
/ @class:
/ CQueryMutators
/
/ @doc:
/ Class providing methods for translating a GPDB Query object into a
/ DXL Tree.
/
/---------------------------------------------------------------------------
class CQueryMutators
{
using MutatorWalkerFn = Node *(*) ();
using ExprWalkerFn = BOOL (*)();
using CContextGrpbyPlMutator = struct SContextGrpbyPlMutator
{
public:
/ memory pool
CMemoryPool *m_mp;
/ MD accessor to get the function name
CMDAccessor *m_mda;
/ original query
Query *m_query;
/ the new target list of the group by or window (lower) query
List *m_lower_table_tlist;
/ the current query level
ULONG m_current_query_level;
/ indicate the levels up of the aggregate we are mutating
ULONG m_agg_levels_up;
/ indicate whether we are mutating the argument of an aggregate
BOOL m_is_mutating_agg_arg;
/ ctor
SContextGrpbyPlMutator(CMemoryPool *mp, CMDAccessor *mda, Query *query,
List *derived_table_tlist)
: m_mp(mp),
m_mda(mda),
m_query(query),
m_lower_table_tlist(derived_table_tlist),
m_current_query_level(0),
m_agg_levels_up(gpos::ulong_max),
m_is_mutating_agg_arg(false)
{
}
/ dtor
~SContextGrpbyPlMutator() = default;
};
using CContextIncLevelsupMutator = struct SContextIncLevelsupMutator
{
public:
/ the current query level
ULONG m_current_query_level;
/ fix target list entry of the top level
BOOL m_should_fix_top_level_target_list;
/ ctor
SContextIncLevelsupMutator(ULONG current_query_level,
BOOL should_fix_top_level_target_list)
: m_current_query_level(current_query_level),
m_should_fix_top_level_target_list(
should_fix_top_level_target_list)
{
}
/ dtor
~SContextIncLevelsupMutator() = default;
};
/ context for walker that iterates over the expression in the target entry
using CContextTLWalker = struct SContextTLWalker
{
public:
/ list of target list entries in the query
List *m_target_entries;
/ list of grouping clauses
List *m_group_clause;
/ ctor
SContextTLWalker(List *target_entries, List *group_clause)
: m_target_entries(target_entries), m_group_clause(group_clause)
{
}
/ dtor
~SContextTLWalker() = default;
};
public:
/ fall back during since the target list refers to a attribute which algebrizer at this point cannot resolve
static BOOL ShouldFallback(Node *node, SContextTLWalker *context);
/ check if the project list contains expressions on aggregates thereby needing normalization
static BOOL NeedsProjListNormalization(const Query *query);
/ normalize query
static Query *NormalizeQuery(CMemoryPool *mp, CMDAccessor *md_accessor,
const Query *query, ULONG query_level);
/ check if the project list contains expressions on window operators thereby needing normalization
static BOOL NeedsProjListWindowNormalization(const Query *query);
/ flatten expressions in window operation project list
static Query *NormalizeWindowProjList(CMemoryPool *mp,
CMDAccessor *md_accessor,
const Query *original_query);
/ traverse the project list to extract all window functions in an arbitrarily complex project element
static Node *RunWindowProjListMutator(Node *node,
SContextGrpbyPlMutator *context);
/ flatten expressions in project list
static Query *NormalizeGroupByProjList(CMemoryPool *mp,
CMDAccessor *md_accessor,
const Query *query);
/ make a copy of the aggref (minus the arguments)
static Aggref *FlatCopyAggref(Aggref *aggref);
/ create a new entry in the derived table and return its corresponding var
static Var *MakeVarInDerivedTable(Node *node,
SContextGrpbyPlMutator *context);
/ check if a matching node exists in the list of target entries
static Node *FindNodeInGroupByTargetList(Node *node,
SContextGrpbyPlMutator *context);
/ increment the levels up of outer references
static Var *IncrLevelsUpIfOuterRef(Var *var);
/ pull up having clause into a select
static Query *NormalizeHaving(CMemoryPool *mp, CMDAccessor *md_accessor,
const Query *query);
/ traverse the expression and fix the levels up of any outer reference
static Node *RunIncrLevelsUpMutator(Node *node,
SContextIncLevelsupMutator *context);
/ traverse the expression and fix the levels up of any CTE
static BOOL RunFixCTELevelsUpWalker(Node *node,
SContextIncLevelsupMutator *context);
/ mutate the grouping columns, fix levels up when necessary
static Node *RunGroupingColMutator(Node *node,
SContextGrpbyPlMutator *context);
/ fix the level up of grouping columns when necessary
static Node *FixGroupingCols(Node *node, TargetEntry *original,
SContextGrpbyPlMutator *context);
/ return a target entry for the aggregate expression
static TargetEntry *GetTargetEntryForAggExpr(CMemoryPool *mp,
CMDAccessor *md_accessor,
Node *node, ULONG attno);
/ traverse the having qual to extract all aggregate functions,
/ fix correlated vars and return the modified having qual
static Node *RunExtractAggregatesMutator(Node *node,
SContextGrpbyPlMutator *context);
/ for a given an TE in the derived table, create a new TE to be added to the top level query
static TargetEntry *MakeTopLevelTargetEntry(TargetEntry *target_entry,
ULONG attno);
/ return the column name of the target entry
static CHAR *GetTargetEntryColName(TargetEntry *target_entry, Query *query);
/ make the input query into a derived table and return a new root query
static Query *ConvertToDerivedTable(const Query *original_query,
BOOL should_fix_target_list,
BOOL should_fix_having_qual);
/ eliminate distinct clause
static Query *EliminateDistinctClause(const Query *query);
/ reassign the sorting clause from the derived table to the new top-level query
static void ReassignSortClause(Query *top_level_query,
Query *derive_table_query);
};
} / namespace gpdxl
#endif / GPDXL_CWalkerUtils_H
/EOF
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