diff options
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/optimizer/path/allpaths.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index 99b6bc8f5a1..e42ef98d8d7 100644 --- a/src/backend/optimizer/path/allpaths.c +++ b/src/backend/optimizer/path/allpaths.c @@ -2254,6 +2254,12 @@ standard_join_search(PlannerInfo *root, int levels_needed, List *initial_rels) * thereby changing the partition contents and thus the window functions' * results for rows that remain. * + * 5. If the subquery contains any set-returning functions in its targetlist, + * we cannot push volatile quals into it. That would push them below the SRFs + * and thereby change the number of times they are evaluated. Also, a + * volatile qual could succeed for some SRF output rows and fail for others, + * a behavior that cannot occur if it's evaluated before SRF expansion. + * * In addition, we make several checks on the subquery's output columns to see * if it is safe to reference them in pushed-down quals. If output column k * is found to be unsafe to reference, we set safetyInfo->unsafeColumns[k] @@ -2298,8 +2304,10 @@ subquery_is_pushdown_safe(Query *subquery, Query *topquery, if (subquery->limitOffset != NULL || subquery->limitCount != NULL) return false; - /* Check points 3 and 4 */ - if (subquery->distinctClause || subquery->hasWindowFuncs) + /* Check points 3, 4, and 5 */ + if (subquery->distinctClause || + subquery->hasWindowFuncs || + subquery->hasTargetSRFs) safetyInfo->unsafeVolatile = true; /* |