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Fix incorrect hash equality operator bug in Memoize

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In v14, because we don't have a field in RestrictInfo to cache both the
left and right type's hash equality operator, we just restrict the scope
of Memoize to only when the left and right types of a RestrictInfo are the
same.

In master we add another field to RestrictInfo and cache both hash
equality operators.

Reported-by: Jaime Casanova
Author: David Rowley
Discussion: https://postgr.es/m/20210929185544.GB24346%40ahch-to
Backpatch-through: 14
This commit is contained in:
David Rowley 2021-11-08 14:41:13 +13:00
parent bb003edbb7
commit 1f194ed6c2
1 changed files with 15 additions and 4 deletions
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19
src/backend/optimizer/plan/initsplan.c
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@ -2719,7 +2719,8 @@ check_memoizable(RestrictInfo *restrictinfo)
{
TypeCacheEntry *typentry;
Expr *clause = restrictinfo->clause;
Node *leftarg;
Oid lefttype;
Oid righttype;
if (restrictinfo->pseudoconstant)
return;
@ -2728,10 +2729,20 @@ check_memoizable(RestrictInfo *restrictinfo)
if (list_length(((OpExpr *) clause)->args) != 2)
return;
leftarg = linitial(((OpExpr *) clause)->args);
lefttype = exprType(linitial(((OpExpr *) clause)->args));
righttype = exprType(lsecond(((OpExpr *) clause)->args));
typentry = lookup_type_cache(exprType(leftarg), TYPECACHE_HASH_PROC |
TYPECACHE_EQ_OPR);
/*
* Really there should be a field for both the left and right hash
* equality operator, however, in v14, there's only a single field in
* RestrictInfo to record the operator in, so we must insist that the left
* and right types match.
*/
if (lefttype != righttype)
return;
typentry = lookup_type_cache(lefttype, TYPECACHE_HASH_PROC |
TYPECACHE_EQ_OPR);
if (!OidIsValid(typentry->hash_proc) || !OidIsValid(typentry->eq_opr))
return;