From fc0f3b4cb0e882a9c5d51c302d4aa3591e4f80fd Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Mon, 18 Oct 2021 20:42:10 +0300 Subject: [PATCH] Fix parallel sort, broken by the balanced merge patch. The code for initializing the tapes on each merge iteration was skipped in a parallel worker. I put the !WORKER(state) check in wrong place while rebasing the patch. That caused failures in the index build in 'multiple-row-versions' isolation test, in multiple buildfarm members. On my laptop it was easier to reproduce by building an index on a larger table, so that you got a parallel sort more reliably. --- src/backend/utils/sort/tuplesort.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c index 0c5c574cbd3..9e93908c657 100644 --- a/src/backend/utils/sort/tuplesort.c +++ b/src/backend/utils/sort/tuplesort.c @@ -2923,7 +2923,7 @@ mergeruns(Tuplesortstate *state) * Rewind all the output tapes, and make them inputs for the next * pass. */ - if (state->nInputRuns == 0 && !WORKER(state)) + if (state->nInputRuns == 0) { int64 input_buffer_size; @@ -2975,7 +2975,8 @@ mergeruns(Tuplesortstate *state) * sorted tape, we can stop at this point and do the final merge * on-the-fly. */ - if (!state->randomAccess && state->nInputRuns <= state->nInputTapes) + if (!state->randomAccess && state->nInputRuns <= state->nInputTapes + && !WORKER(state)) { /* Tell logtape.c we won't be writing anymore */ LogicalTapeSetForgetFreeSpace(state->tapeset);