database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-19 13:42:17 +03:00
Code Activity

Fix handling of opclauses in extended statistics

Browse Source 
We expect opclauses to have exactly one Var and one Const, but the code
was checking the Const by calling is_pseudo_constant_clause() which is
incorrect - we need a proper constant.

Fixed by using plain IsA(x,Const) to check type of the node. We need to
do these checks in two places, so move it into a separate function that
can be called in both places.

Reported by Andreas Seltenreich, based on crash reported by sqlsmith.

Backpatch to v12, where this code was introduced.

Discussion: https://postgr.es/m/8736jdhbhc.fsf%40ansel.ydns.eu
Backpatch-to: 12
This commit is contained in:
Tomas Vondra
2019-07-13 00:12:16 +02:00
parent a4303a078c
commit e8b6ae2130
3 changed files with 73 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

27
src/backend/statistics/mcv.c
View File

@@ -1561,36 +1561,23 @@ mcv_get_match_bitmap(PlannerInfo *root, List *clauses,
if (is_opclause(clause))
{
OpExpr *expr = (OpExpr *) clause;
bool varonleft = true;
bool ok;
FmgrInfo opproc;
/* get procedure computing operator selectivity */
RegProcedure oprrest = get_oprrest(expr->opno);
/* valid only after examine_opclause_expression returns true */
Var *var;
Const *cst;
bool isgt;
fmgr_info(get_opcode(expr->opno), &opproc);
ok = (NumRelids(clause) == 1) &&
(is_pseudo_constant_clause(lsecond(expr->args)) ||
(varonleft = false,
is_pseudo_constant_clause(linitial(expr->args))));
if (ok)
/* extract the var and const from the expression */
if (examine_opclause_expression(expr, &var, &cst, &isgt))
{
Var *var;
Const *cst;
bool isgt;
int idx;
/* extract the var and const from the expression */
var = (varonleft) ? linitial(expr->args) : lsecond(expr->args);
cst = (varonleft) ? lsecond(expr->args) : linitial(expr->args);
isgt = (!varonleft);
/* strip binary-compatible relabeling */
if (IsA(var, RelabelType))
var = (Var *) ((RelabelType *) var)->arg;
/* match the attribute to a dimension of the statistic */
idx = bms_member_index(keys, var->varattno);