diff options
Diffstat (limited to 'src/backend/optimizer/util/relnode.c')
| -rw-r--r-- | src/backend/optimizer/util/relnode.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c index 85415381fb1..03e02423b2e 100644 --- a/src/backend/optimizer/util/relnode.c +++ b/src/backend/optimizer/util/relnode.c @@ -843,6 +843,7 @@ build_child_join_rel(PlannerInfo *root, RelOptInfo *outer_rel, /* Compute information relevant to foreign relations. */ set_foreign_rel_properties(joinrel, outer_rel, inner_rel); + /* Compute information needed for mapping Vars to the child rel */ appinfos = find_appinfos_by_relids(root, joinrel->relids, &nappinfos); /* Set up reltarget struct */ @@ -854,7 +855,6 @@ build_child_join_rel(PlannerInfo *root, RelOptInfo *outer_rel, (Node *) parent_joinrel->joininfo, nappinfos, appinfos); - pfree(appinfos); /* * Lateral relids referred in child join will be same as that referred in @@ -886,6 +886,19 @@ build_child_join_rel(PlannerInfo *root, RelOptInfo *outer_rel, /* Add the relation to the PlannerInfo. */ add_join_rel(root, joinrel); + /* + * We might need EquivalenceClass members corresponding to the child join, + * so that we can represent sort pathkeys for it. As with children of + * baserels, we shouldn't need this unless there are relevant eclass joins + * (implying that a merge join might be possible) or pathkeys to sort by. + */ + if (joinrel->has_eclass_joins || has_useful_pathkeys(root, parent_joinrel)) + add_child_join_rel_equivalences(root, + nappinfos, appinfos, + parent_joinrel, joinrel); + + pfree(appinfos); + return joinrel; } |