From 8bf66dedd88673f94122c3f3337e7d58e561ef4f Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 18 Oct 2022 10:44:34 -0400 Subject: Fix confusion about havingQual vs hasHavingQual in planner. Preprocessing of the HAVING clause will reduce havingQual to NIL if the clause is constant-TRUE. This is one case where that convention is rather unfortunate, because "HAVING TRUE" is not at all the same as not having any HAVING clause at all. (Per the SQL spec, it still forces the query to be grouped.) The planner deals with this by having a boolean hasHavingQual that records whether havingQual was originally nonempty; places that just want to check whether HAVING was specified are supposed to consult that. I found three places that got that wrong. Fortunately, these could only affect cost estimates not correctness. It'd be hard even to demonstrate the errors; for example, the one in allpaths.c would only matter in a query that has HAVING TRUE but no GROUP BY and no aggregates, which would require a completely variable-free SELECT list, making the case probably of only academic interest. Hence, while these are worth fixing before someone copies the incorrect coding somewhere more critical, they don't seem worth back-patching. I didn't bother trying to devise regression tests, either. Discussion: https://postgr.es/m/2503888.1666042643@sss.pgh.pa.us --- contrib/postgres_fdw/postgres_fdw.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'contrib/postgres_fdw/postgres_fdw.c') diff --git a/contrib/postgres_fdw/postgres_fdw.c b/contrib/postgres_fdw/postgres_fdw.c index d98709e5e88..8d7500abfbd 100644 --- a/contrib/postgres_fdw/postgres_fdw.c +++ b/contrib/postgres_fdw/postgres_fdw.c @@ -3357,7 +3357,7 @@ estimate_path_cost_size(PlannerInfo *root, * Get the retrieved_rows and rows estimates. If there are HAVING * quals, account for their selectivity. */ - if (root->parse->havingQual) + if (root->hasHavingQual) { /* Factor in the selectivity of the remotely-checked quals */ retrieved_rows = @@ -3405,7 +3405,7 @@ estimate_path_cost_size(PlannerInfo *root, run_cost += cpu_tuple_cost * numGroups; /* Account for the eval cost of HAVING quals, if any */ - if (root->parse->havingQual) + if (root->hasHavingQual) { QualCost remote_cost; -- cgit v1.2.3