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Use single WAL record for 0-extension of relations

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Bulk materialization of empty pages at logging of new last relation block is handled in the Pageserver already, so no need for us to log those pages.
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MMeent
2023-09-27 15:15:41 +02:00
committed by GitHub
parent 090a644392
commit 84ea96a3a5
1 changed files with 12 additions and 28 deletions
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40
pgxn/neon/pagestore_smgr.c
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@@ -1790,39 +1790,23 @@ neon_zeroextend(SMgrRelation reln, ForkNumber forkNum, BlockNumber blocknum,
if (!XLogInsertAllowed())
return;
/* ensure we have enough xlog buffers to log max-sized records */
XLogEnsureRecordSpace(Min(remblocks, (XLR_MAX_BLOCK_ID - 1)), 0);
/*
* Iterate over all the pages. They are collected into batches of
* XLR_MAX_BLOCK_ID pages, and a single WAL-record is written for each
* batch.
* Pageserver auto-extends relations with 0s, so WAL-logging only the last
* page is enough here (else we'd log each page 2 times with 0-bytes.
*/
while (remblocks > 0)
{
int count = Min(remblocks, XLR_MAX_BLOCK_ID);
XLogBeginInsert();
for (int i = 0; i < count; i++)
XLogRegisterBlock(i, &InfoFromSMgrRel(reln), forkNum, blocknum + i,
(char *) buffer.data, REGBUF_FORCE_IMAGE | REGBUF_STANDARD);
lsn = XLogInsert(RM_XLOG_ID, XLOG_FPI);
for (int i = 0; i < count; i++)
{
lfc_write(InfoFromSMgrRel(reln), forkNum, blocknum + i, buffer.data);
SetLastWrittenLSNForBlock(lsn, InfoFromSMgrRel(reln), forkNum,
blocknum + i);
}
blocknum += count;
remblocks -= count;
}
XLogBeginInsert();
XLogRegisterBlock(0, &InfoFromSMgrRel(reln), forkNum, blocknum + nblocks, (char *) &buffer.data, REGBUF_FORCE_IMAGE);
lsn = XLogInsert(RM_XLOG_ID, XLOG_FPI);
Assert(lsn != 0);
for (uint32 i = blocknum; i < blocknum + nblocks; i++)
{
lfc_write(InfoFromSMgrRel(reln), forkNum, blocknum + i, buffer.data);
SetLastWrittenLSNForBlock(lsn, InfoFromSMgrRel(reln), forkNum,
blocknum + i);
}
SetLastWrittenLSNForRelation(lsn, InfoFromSMgrRel(reln), forkNum);
set_cached_relsize(InfoFromSMgrRel(reln), forkNum, blocknum);
}