Files
postgresql/src/include/optimizer/clauses.h
Tom Lane 0fbd44387d Make equal() ignore CoercionForm fields for better planning with casts.
This change ensures that the planner will see implicit and explicit casts
as equivalent for all purposes, except in the minority of cases where
there's actually a semantic difference (as reflected by having a 3-argument
cast function).  In particular, this fixes cases where the EquivalenceClass
machinery failed to consider two references to a varchar column as
equivalent if one was implicitly cast to text but the other was explicitly
cast to text, as seen in bug #7598 from Vaclav Juza.  We have had similar
bugs before in other parts of the planner, so I think it's time to fix this
problem at the core instead of continuing to band-aid around it.

Remove set_coercionform_dontcare(), which represents the band-aid
previously in use for allowing matching of index and constraint expressions
with inconsistent cast labeling.  (We can probably get rid of
COERCE_DONTCARE altogether, but I don't think removing that enum value in
back branches would be wise; it's possible there's third party code
referring to it.)

Back-patch to 9.2.  We could go back further, and might want to once this
has been tested more; but for the moment I won't risk destabilizing plan
choices in long-since-stable branches.
2012-10-12 12:10:55 -04:00

90 lines
2.9 KiB
C

/*-------------------------------------------------------------------------
*
* clauses.h
* prototypes for clauses.c.
*
*
* Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/optimizer/clauses.h
*
*-------------------------------------------------------------------------
*/
#ifndef CLAUSES_H
#define CLAUSES_H
#include "nodes/relation.h"
#define is_opclause(clause) ((clause) != NULL && IsA(clause, OpExpr))
#define is_funcclause(clause) ((clause) != NULL && IsA(clause, FuncExpr))
typedef struct
{
int numWindowFuncs; /* total number of WindowFuncs found */
Index maxWinRef; /* windowFuncs[] is indexed 0 .. maxWinRef */
List **windowFuncs; /* lists of WindowFuncs for each winref */
} WindowFuncLists;
extern Expr *make_opclause(Oid opno, Oid opresulttype, bool opretset,
Expr *leftop, Expr *rightop,
Oid opcollid, Oid inputcollid);
extern Node *get_leftop(const Expr *clause);
extern Node *get_rightop(const Expr *clause);
extern bool not_clause(Node *clause);
extern Expr *make_notclause(Expr *notclause);
extern Expr *get_notclausearg(Expr *notclause);
extern bool or_clause(Node *clause);
extern Expr *make_orclause(List *orclauses);
extern bool and_clause(Node *clause);
extern Expr *make_andclause(List *andclauses);
extern Node *make_and_qual(Node *qual1, Node *qual2);
extern Expr *make_ands_explicit(List *andclauses);
extern List *make_ands_implicit(Expr *clause);
extern bool contain_agg_clause(Node *clause);
extern void count_agg_clauses(PlannerInfo *root, Node *clause,
AggClauseCosts *costs);
extern bool contain_window_function(Node *clause);
extern WindowFuncLists *find_window_functions(Node *clause, Index maxWinRef);
extern double expression_returns_set_rows(Node *clause);
extern double tlist_returns_set_rows(List *tlist);
extern bool contain_subplans(Node *clause);
extern bool contain_mutable_functions(Node *clause);
extern bool contain_volatile_functions(Node *clause);
extern bool contain_nonstrict_functions(Node *clause);
extern bool contain_leaky_functions(Node *clause);
extern Relids find_nonnullable_rels(Node *clause);
extern List *find_nonnullable_vars(Node *clause);
extern List *find_forced_null_vars(Node *clause);
extern Var *find_forced_null_var(Node *clause);
extern bool is_pseudo_constant_clause(Node *clause);
extern bool is_pseudo_constant_clause_relids(Node *clause, Relids relids);
extern int NumRelids(Node *clause);
extern void CommuteOpExpr(OpExpr *clause);
extern void CommuteRowCompareExpr(RowCompareExpr *clause);
extern Node *strip_implicit_coercions(Node *node);
extern Node *eval_const_expressions(PlannerInfo *root, Node *node);
extern Node *estimate_expression_value(PlannerInfo *root, Node *node);
extern Query *inline_set_returning_function(PlannerInfo *root,
RangeTblEntry *rte);
#endif /* CLAUSES_H */