diff options
Diffstat (limited to 'src/backend/optimizer/path/allpaths.c')
| -rw-r--r-- | src/backend/optimizer/path/allpaths.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index 8e8f43735e0..27bec72d452 100644 --- a/src/backend/optimizer/path/allpaths.c +++ b/src/backend/optimizer/path/allpaths.c @@ -3295,8 +3295,10 @@ qual_is_pushdown_safe(Query *subquery, Index rti, Node *qual, Assert(!contain_window_function(qual)); /* - * Examine all Vars used in clause; since it's a restriction clause, all - * such Vars must refer to subselect output columns. + * Examine all Vars used in clause. Since it's a restriction clause, all + * such Vars must refer to subselect output columns ... unless this is + * part of a LATERAL subquery, in which case there could be lateral + * references. */ vars = pull_var_clause(qual, PVC_INCLUDE_PLACEHOLDERS); foreach(vl, vars) @@ -3316,7 +3318,19 @@ qual_is_pushdown_safe(Query *subquery, Index rti, Node *qual, break; } - Assert(var->varno == rti); + /* + * Punt if we find any lateral references. It would be safe to push + * these down, but we'd have to convert them into outer references, + * which subquery_push_qual lacks the infrastructure to do. The case + * arises so seldom that it doesn't seem worth working hard on. + */ + if (var->varno != rti) + { + safe = false; + break; + } + + /* Subqueries have no system columns */ Assert(var->varattno >= 0); /* Check point 4 */ |