diff options
Diffstat (limited to 'src/backend/optimizer/path/pathkeys.c')
| -rw-r--r-- | src/backend/optimizer/path/pathkeys.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c index 3f1a4050e74..1d61881a6b6 100644 --- a/src/backend/optimizer/path/pathkeys.c +++ b/src/backend/optimizer/path/pathkeys.c @@ -2192,6 +2192,22 @@ pathkeys_useful_for_grouping(PlannerInfo *root, List *pathkeys) } /* + * pathkeys_useful_for_setop + * Count the number of leading common pathkeys root's 'setop_pathkeys' in + * 'pathkeys'. + */ +static int +pathkeys_useful_for_setop(PlannerInfo *root, List *pathkeys) +{ + int n_common_pathkeys; + + (void) pathkeys_count_contained_in(root->setop_pathkeys, pathkeys, + &n_common_pathkeys); + + return n_common_pathkeys; +} + +/* * truncate_useless_pathkeys * Shorten the given pathkey list to just the useful pathkeys. */ @@ -2210,6 +2226,9 @@ truncate_useless_pathkeys(PlannerInfo *root, nuseful2 = pathkeys_useful_for_grouping(root, pathkeys); if (nuseful2 > nuseful) nuseful = nuseful2; + nuseful2 = pathkeys_useful_for_setop(root, pathkeys); + if (nuseful2 > nuseful) + nuseful = nuseful2; /* * Note: not safe to modify input list destructively, but we can avoid |