From 10fcb83da6a7c5328f61ca7fb60f78c57db1bd58 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 4 Feb 2021 19:12:09 -0500 Subject: Fix YA incremental sort bug. switchToPresortedPrefixMode() did the wrong thing if it detected a batch boundary just at the last tuple of a fullsort group. The initially-reported symptom was a "retrieved too many tuples in a bounded sort" error, but the test case added here just silently gives the wrong answer without this patch. I (tgl) am not really happy about committing this patch without review from the incremental-sort authors, but they seem AWOL and we are hard against a release deadline. This does demonstrably make some cases better, anyway. Per bug #16846 from Yoran Heling. Back-patch to v13 where incremental sort was introduced. Neil Chen Discussion: https://postgr.es/m/16846-ae49f51ac379a4cb@postgresql.org --- src/backend/executor/nodeIncrementalSort.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'src/backend/executor') diff --git a/src/backend/executor/nodeIncrementalSort.c b/src/backend/executor/nodeIncrementalSort.c index b53f8a01810..360aad32c5c 100644 --- a/src/backend/executor/nodeIncrementalSort.c +++ b/src/backend/executor/nodeIncrementalSort.c @@ -394,6 +394,13 @@ switchToPresortedPrefixMode(PlanState *pstate) * current prefix key group. */ ExecClearTuple(node->group_pivot); + + /* + * Also make sure we take the didn't-consume-all-the-tuples + * path below, even if this happened to be the last tuple of + * the batch. + */ + lastTuple = false; break; } } -- cgit v1.2.3