diff options
Diffstat (limited to 'src/backend/optimizer/plan/setrefs.c')
| -rw-r--r-- | src/backend/optimizer/plan/setrefs.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c index 6ea35056465..d95fd898077 100644 --- a/src/backend/optimizer/plan/setrefs.c +++ b/src/backend/optimizer/plan/setrefs.c @@ -2748,7 +2748,7 @@ search_indexed_tlist_for_sortgroupref(Expr *node, * relation target lists. Also perform opcode lookup and add * regclass OIDs to root->glob->relationOids. * - * This is used in three different scenarios: + * This is used in four different scenarios: * 1) a normal join clause, where all the Vars in the clause *must* be * replaced by OUTER_VAR or INNER_VAR references. In this case * acceptable_rel should be zero so that any failure to match a Var will be @@ -2763,6 +2763,11 @@ search_indexed_tlist_for_sortgroupref(Expr *node, * to-be-updated relation) alone. Correspondingly inner_itlist is to be * EXCLUDED elements, outer_itlist = NULL and acceptable_rel the target * relation. + * 4) MERGE. In this case, references to the source relation are to be + * replaced with INNER_VAR references, leaving Vars of the target + * relation (the to-be-modified relation) alone. So inner_itlist is to be + * the source relation elements, outer_itlist = NULL and acceptable_rel + * the target relation. * * 'clauses' is the targetlist or list of join clauses * 'outer_itlist' is the indexed target list of the outer join relation, |