From 2a11dc5ef62408bb455277eb73c83abc8f9d2bf3 Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Mon, 12 Feb 2024 19:03:24 -0500 Subject: [PATCH v2 04/13] BitmapPrefetch use prefetch block recheck for skip fetch As of 7c70996ebf0949b142a9, BitmapPrefetch() used the recheck flag for the current block to determine whether or not it could skip prefetching the proposed prefetch block. It makes more sense for it to use the recheck flag from the TBMIterateResult for the prefetch block instead. See this [1] thread on hackers reporting the issue. [1] https://www.postgresql.org/message-id/CAAKRu_bxrXeZ2rCnY8LyeC2Ls88KpjWrQ%2BopUrXDRXdcfwFZGA%40mail.gmail.com --- src/backend/executor/nodeBitmapHeapscan.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c index be08bd785ae..c6dfdf8cae9 100644 --- a/src/backend/executor/nodeBitmapHeapscan.c +++ b/src/backend/executor/nodeBitmapHeapscan.c @@ -532,7 +532,7 @@ BitmapPrefetch(BitmapHeapScanState *node, TableScanDesc scan) * but is true in many cases. */ skip_fetch = (node->can_skip_fetch && - (node->tbmres ? !node->tbmres->recheck : false) && + !tbmpre->recheck && VM_ALL_VISIBLE(node->ss.ss_currentRelation, tbmpre->blockno, &node->pvmbuffer)); @@ -583,7 +583,7 @@ BitmapPrefetch(BitmapHeapScanState *node, TableScanDesc scan) /* As above, skip prefetch if we expect not to need page */ skip_fetch = (node->can_skip_fetch && - (node->tbmres ? !node->tbmres->recheck : false) && + !tbmpre->recheck && VM_ALL_VISIBLE(node->ss.ss_currentRelation, tbmpre->blockno, &node->pvmbuffer)); -- 2.37.2