diff options
| -rw-r--r-- | src/backend/optimizer/prep/prepunion.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c index 2e55131a591..e80ad7753de 100644 --- a/src/backend/optimizer/prep/prepunion.c +++ b/src/backend/optimizer/prep/prepunion.c @@ -594,12 +594,13 @@ generate_nonunion_plan(SetOperationStmt *op, PlannerInfo *root, /* Identify the grouping semantics */ groupList = generate_setop_grouplist(op, tlist); - /* punt if nothing to group on (can this happen?) */ + /* punt if nothing to group on (not worth fixing in back branches) */ if (groupList == NIL) - { - *sortClauses = NIL; - return plan; - } + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + /* translator: %s is UNION, INTERSECT, or EXCEPT */ + errmsg("%s over no columns is not supported", + (op->op == SETOP_INTERSECT) ? "INTERSECT" : "EXCEPT"))); /* * Estimate number of distinct groups that we'll need hashtable entries @@ -738,12 +739,12 @@ make_union_unique(SetOperationStmt *op, Plan *plan, /* Identify the grouping semantics */ groupList = generate_setop_grouplist(op, plan->targetlist); - /* punt if nothing to group on (can this happen?) */ + /* punt if nothing to group on (not worth fixing in back branches) */ if (groupList == NIL) - { - *sortClauses = NIL; - return plan; - } + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + /* translator: %s is UNION, INTERSECT, or EXCEPT */ + errmsg("%s over no columns is not supported", "UNION"))); /* * XXX for the moment, take the number of distinct groups as equal to the |