diff options
Diffstat (limited to 'src/backend/optimizer/path/joinpath.c')
| -rw-r--r-- | src/backend/optimizer/path/joinpath.c | 30 |
1 files changed, 11 insertions, 19 deletions
diff --git a/src/backend/optimizer/path/joinpath.c b/src/backend/optimizer/path/joinpath.c index f54c3931ce4..d87ba464014 100644 --- a/src/backend/optimizer/path/joinpath.c +++ b/src/backend/optimizer/path/joinpath.c @@ -149,28 +149,20 @@ add_paths_to_joinrel(PlannerInfo *root, /* * However, when a LATERAL subquery is involved, we have to be a bit - * laxer, because there may simply not be any paths for the joinrel that - * aren't parameterized by whatever the subquery is parameterized by. - * Hence, add to param_source_rels anything that is in the minimum - * parameterization of either input (and not in the other input). - * - * XXX need a more principled way of determining minimum parameterization. + * laxer, because there will simply not be any paths for the joinrel that + * aren't parameterized by whatever the subquery is parameterized by, + * unless its parameterization is resolved within the joinrel. Hence, add + * to param_source_rels anything that is laterally referenced in either + * input and is not in the join already. */ - if (outerrel->cheapest_total_path == NULL) + foreach(lc, root->lateral_info_list) { - Path *cheapest = (Path *) linitial(outerrel->cheapest_parameterized_paths); + LateralJoinInfo *ljinfo = (LateralJoinInfo *) lfirst(lc); - param_source_rels = bms_join(param_source_rels, - bms_difference(PATH_REQ_OUTER(cheapest), - innerrel->relids)); - } - if (innerrel->cheapest_total_path == NULL) - { - Path *cheapest = (Path *) linitial(innerrel->cheapest_parameterized_paths); - - param_source_rels = bms_join(param_source_rels, - bms_difference(PATH_REQ_OUTER(cheapest), - outerrel->relids)); + if (bms_is_member(ljinfo->lateral_rhs, joinrel->relids)) + param_source_rels = bms_join(param_source_rels, + bms_difference(ljinfo->lateral_lhs, + joinrel->relids)); } /* |