diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/utils/adt/selfuncs.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c index ce6a626eba2..17fbfa9b410 100644 --- a/src/backend/utils/adt/selfuncs.c +++ b/src/backend/utils/adt/selfuncs.c @@ -3798,18 +3798,25 @@ estimate_multivariate_bucketsize(PlannerInfo *root, RelOptInfo *inner, List *hashclauses, Selectivity *innerbucketsize) { - List *clauses = list_copy(hashclauses); - List *otherclauses = NIL; - double ndistinct = 1.0; + List *clauses; + List *otherclauses; + double ndistinct; if (list_length(hashclauses) <= 1) - + { /* * Nothing to do for a single clause. Could we employ univariate * extended stat here? */ return hashclauses; + } + /* "clauses" is the list of hashclauses we've not dealt with yet */ + clauses = list_copy(hashclauses); + /* "otherclauses" holds clauses we are going to return to caller */ + otherclauses = NIL; + /* current estimate of ndistinct */ + ndistinct = 1.0; while (clauses != NIL) { ListCell *lc; @@ -3874,12 +3881,13 @@ estimate_multivariate_bucketsize(PlannerInfo *root, RelOptInfo *inner, group_rel = root->simple_rel_array[relid]; } else if (group_relid != relid) - + { /* * Being in the group forming state we don't need other * clauses. */ continue; + } /* * We're going to add the new clause to the varinfos list. We |