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| author | Thomas Munro <tmunro@postgresql.org> | 2023-09-05 18:26:12 +1200 |
|---|---|---|
| committer | Thomas Munro <tmunro@postgresql.org> | 2023-09-05 19:53:43 +1200 |
| commit | f691f5b80a85c66d715b4340ffabb503eb19393e (patch) | |
| tree | 26a06c87096de2f9571956b4370ccbf1852d4cba /src/backend/access/gin/ginget.c | |
| parent | aa0d3504560d40f4300a3d49d1c6c3bfc3b894e5 (diff) | |
| download | postgresql-f691f5b80a85c66d715b4340ffabb503eb19393e.tar.gz postgresql-f691f5b80a85c66d715b4340ffabb503eb19393e.zip | |
Remove the "snapshot too old" feature.
Remove the old_snapshot_threshold setting and mechanism for producing
the error "snapshot too old", originally added by commit 848ef42b.
Unfortunately it had a number of known problems in terms of correctness
and performance, mostly reported by Andres in the course of his work on
snapshot scalability. We agreed to remove it, after a long period
without an active plan to fix it.
This is certainly a desirable feature, and someone might propose a new
or improved implementation in the future.
Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/CACG%3DezYV%2BEvO135fLRdVn-ZusfVsTY6cH1OZqWtezuEYH6ciQA%40mail.gmail.com
Discussion: https://postgr.es/m/20200401064008.qob7bfnnbu4w5cw4%40alap3.anarazel.de
Discussion: https://postgr.es/m/CA%2BTgmoY%3Daqf0zjTD%2B3dUWYkgMiNDegDLFjo%2B6ze%3DWtpik%2B3XqA%40mail.gmail.com
Diffstat (limited to 'src/backend/access/gin/ginget.c')
| -rw-r--r-- | src/backend/access/gin/ginget.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/src/backend/access/gin/ginget.c b/src/backend/access/gin/ginget.c index 1f0214498cd..10d2bb89008 100644 --- a/src/backend/access/gin/ginget.c +++ b/src/backend/access/gin/ginget.c @@ -158,7 +158,6 @@ collectMatchBitmap(GinBtreeData *btree, GinBtreeStack *stack, return true; page = BufferGetPage(stack->buffer); - TestForOldSnapshot(snapshot, btree->index, page); itup = (IndexTuple) PageGetItem(page, PageGetItemId(page, stack->off)); /* @@ -1460,7 +1459,6 @@ scanGetCandidate(IndexScanDesc scan, pendingPosition *pos) for (;;) { page = BufferGetPage(pos->pendingBuffer); - TestForOldSnapshot(scan->xs_snapshot, scan->indexRelation, page); maxoff = PageGetMaxOffsetNumber(page); if (pos->firstOffset > maxoff) @@ -1641,7 +1639,6 @@ collectMatchesForHeapRow(IndexScanDesc scan, pendingPosition *pos) sizeof(bool) * (pos->lastOffset - pos->firstOffset)); page = BufferGetPage(pos->pendingBuffer); - TestForOldSnapshot(scan->xs_snapshot, scan->indexRelation, page); for (i = 0; i < so->nkeys; i++) { @@ -1844,7 +1841,6 @@ scanPendingInsert(IndexScanDesc scan, TIDBitmap *tbm, int64 *ntids) LockBuffer(metabuffer, GIN_SHARE); page = BufferGetPage(metabuffer); - TestForOldSnapshot(scan->xs_snapshot, scan->indexRelation, page); blkno = GinPageGetMeta(page)->head; /* |