diff options
Diffstat (limited to 'src/backend/utils/adt/selfuncs.c')
| -rw-r--r-- | src/backend/utils/adt/selfuncs.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c index 91399f79fc8..04ed07b762d 100644 --- a/src/backend/utils/adt/selfuncs.c +++ b/src/backend/utils/adt/selfuncs.c @@ -3158,6 +3158,8 @@ add_unique_group_var(PlannerInfo *root, List *varinfos, * groupExprs - list of expressions being grouped by * input_rows - number of rows estimated to arrive at the group/unique * filter step + * pgset - NULL, or a List** pointing to a grouping set to filter the + * groupExprs against * * Given the lack of any cross-correlation statistics in the system, it's * impossible to do anything really trustworthy with GROUP BY conditions @@ -3205,11 +3207,13 @@ add_unique_group_var(PlannerInfo *root, List *varinfos, * but we don't have the info to do better). */ double -estimate_num_groups(PlannerInfo *root, List *groupExprs, double input_rows) +estimate_num_groups(PlannerInfo *root, List *groupExprs, double input_rows, + List **pgset) { List *varinfos = NIL; double numdistinct; ListCell *l; + int i; /* * We don't ever want to return an estimate of zero groups, as that tends @@ -3224,7 +3228,7 @@ estimate_num_groups(PlannerInfo *root, List *groupExprs, double input_rows) * for normal cases with GROUP BY or DISTINCT, but it is possible for * corner cases with set operations.) */ - if (groupExprs == NIL) + if (groupExprs == NIL || (pgset && list_length(*pgset) < 1)) return 1.0; /* @@ -3236,6 +3240,7 @@ estimate_num_groups(PlannerInfo *root, List *groupExprs, double input_rows) */ numdistinct = 1.0; + i = 0; foreach(l, groupExprs) { Node *groupexpr = (Node *) lfirst(l); @@ -3243,6 +3248,10 @@ estimate_num_groups(PlannerInfo *root, List *groupExprs, double input_rows) List *varshere; ListCell *l2; + /* is expression in this grouping set? */ + if (pgset && !list_member_int(*pgset, i++)) + continue; + /* Short-circuit for expressions returning boolean */ if (exprType(groupexpr) == BOOLOID) { |