From 74197bdc842a280befe834e5cb4be700af9f8198 Mon Sep 17 00:00:00 2001 From: Peter Eisentraut Date: Tue, 28 Oct 2025 10:06:03 +0100 Subject: [PATCH] Check that index can return in get_actual_variable_range() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some recent changes were made to remove the explicit dependency on btree indexes in some parts of the code. One of these changes was made in commit 9ef1851685b, which allows non-btree indexes to be used in get_actual_variable_range(). A follow-up commit ee1ae8b99f9 fixes the cases where an index doesn’t have a sortopfamily as this is a prerequisite to be used in get_actual_variable_range(). However, it was found that indexes that have amcanorder = true but do not allow index-only-scans (amcanreturn returns false or is NULL) will pass all of the conditions, while they should be rejected since get_actual_variable_range() uses the index-only-scan machinery in get_actual_variable_endpoint(). Such an index might cause errors like ERROR: no data returned for index-only scan during query planning. The fix is to add a check in get_actual_variable_range() to reject indexes that do not allow index-only scans. Author: Maxime Schoemans Discussion: https://www.postgresql.org/message-id/flat/20ED852A-C2D9-41EB-8671-8C8B9D418BE9%40enterprisedb.com --- src/backend/utils/adt/selfuncs.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c index 65ae682e298..c82bacd7c15 100644 --- a/src/backend/utils/adt/selfuncs.c +++ b/src/backend/utils/adt/selfuncs.c @@ -6554,6 +6554,13 @@ get_actual_variable_range(PlannerInfo *root, VariableStatData *vardata, if (index->hypothetical) continue; + /* + * get_actual_variable_endpoint uses the index-only-scan machinery, so + * ignore indexes that can't use it on their first column. + */ + if (!index->canreturn[0]) + continue; + /* * The first index column must match the desired variable, sortop, and * collation --- but we can use a descending-order index.