From 4c11d2c559e76892156fd08d6a3cf5e1848a017f Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 3 Nov 2017 16:31:32 -0400 Subject: [PATCH] Flag index metapages as standard-format in xlog.c calls. btree, hash, and bloom indexes all set up their metapages in standard format (that is, with pd_lower and pd_upper correctly delimiting the unused area); but they mostly didn't inform the xlog routines of this. When calling log_newpage[_buffer], this is bad because it loses the opportunity to compress unused data out of the WAL record. When calling XLogRegisterBuffer, it's not such a performance problem because all of these call sites also use REGBUF_WILL_INIT, preventing an FPI image from being written. But it's still a good idea to provide the flag when relevant, because that aids WAL consistency checking. This completes the project of getting all the in-core index AMs to handle their metapage WAL operations similarly. Amit Kapila, reviewed by Michael Paquier Discussion: https://postgr.es/m/0d273805-0e9e-ec1a-cb84-d4da400b8f85@lab.ntt.co.jp --- contrib/bloom/blinsert.c | 2 +- src/backend/access/hash/hashpage.c | 7 ++++--- src/backend/access/nbtree/nbtinsert.c | 4 ++-- src/backend/access/nbtree/nbtpage.c | 9 +++++---- src/backend/access/nbtree/nbtree.c | 2 +- src/backend/access/nbtree/nbtxlog.c | 5 +++-- 6 files changed, 16 insertions(+), 13 deletions(-) diff --git a/contrib/bloom/blinsert.c b/contrib/bloom/blinsert.c index 0d506e3c1a..1fcb281508 100644 --- a/contrib/bloom/blinsert.c +++ b/contrib/bloom/blinsert.c @@ -175,7 +175,7 @@ blbuildempty(Relation index) smgrwrite(index->rd_smgr, INIT_FORKNUM, BLOOM_METAPAGE_BLKNO, (char *) metapage, true); log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM, - BLOOM_METAPAGE_BLKNO, metapage, false); + BLOOM_METAPAGE_BLKNO, metapage, true); /* * An immediate sync is required even if we xlog'd the page, because the diff --git a/src/backend/access/hash/hashpage.c b/src/backend/access/hash/hashpage.c index f279dcea1d..4b14f88af9 100644 --- a/src/backend/access/hash/hashpage.c +++ b/src/backend/access/hash/hashpage.c @@ -403,7 +403,7 @@ _hash_init(Relation rel, double num_tuples, ForkNumber forkNum) XLogBeginInsert(); XLogRegisterData((char *) &xlrec, SizeOfHashInitMetaPage); - XLogRegisterBuffer(0, metabuf, REGBUF_WILL_INIT); + XLogRegisterBuffer(0, metabuf, REGBUF_WILL_INIT | REGBUF_STANDARD); recptr = XLogInsert(RM_HASH_ID, XLOG_HASH_INIT_META_PAGE); @@ -592,8 +592,9 @@ _hash_init_metabuffer(Buffer buf, double num_tuples, RegProcedure procid, metap->hashm_firstfree = 0; /* - * Set pd_lower just past the end of the metadata. This is to log full - * page image of metapage in xloginsert.c. + * Set pd_lower just past the end of the metadata. This is essential, + * because without doing so, metadata will be lost if xlog.c compresses + * the page. */ ((PageHeader) page)->pd_lower = ((char *) metap + sizeof(HashMetaPageData)) - (char *) page; diff --git a/src/backend/access/nbtree/nbtinsert.c b/src/backend/access/nbtree/nbtinsert.c index bf963fcdef..5cbaba1b7d 100644 --- a/src/backend/access/nbtree/nbtinsert.c +++ b/src/backend/access/nbtree/nbtinsert.c @@ -898,7 +898,7 @@ _bt_insertonpg(Relation rel, xlmeta.fastroot = metad->btm_fastroot; xlmeta.fastlevel = metad->btm_fastlevel; - XLogRegisterBuffer(2, metabuf, REGBUF_WILL_INIT); + XLogRegisterBuffer(2, metabuf, REGBUF_WILL_INIT | REGBUF_STANDARD); XLogRegisterBufData(2, (char *) &xlmeta, sizeof(xl_btree_metadata)); xlinfo = XLOG_BTREE_INSERT_META; @@ -2032,7 +2032,7 @@ _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf) XLogRegisterBuffer(0, rootbuf, REGBUF_WILL_INIT); XLogRegisterBuffer(1, lbuf, REGBUF_STANDARD); - XLogRegisterBuffer(2, metabuf, REGBUF_WILL_INIT); + XLogRegisterBuffer(2, metabuf, REGBUF_WILL_INIT | REGBUF_STANDARD); md.root = rootblknum; md.level = metad->btm_level; diff --git a/src/backend/access/nbtree/nbtpage.c b/src/backend/access/nbtree/nbtpage.c index 10697e9e23..c77434904e 100644 --- a/src/backend/access/nbtree/nbtpage.c +++ b/src/backend/access/nbtree/nbtpage.c @@ -65,8 +65,9 @@ _bt_initmetapage(Page page, BlockNumber rootbknum, uint32 level) metaopaque->btpo_flags = BTP_META; /* - * Set pd_lower just past the end of the metadata. This is not essential - * but it makes the page look compressible to xlog.c. + * Set pd_lower just past the end of the metadata. This is essential, + * because without doing so, metadata will be lost if xlog.c compresses + * the page. */ ((PageHeader) page)->pd_lower = ((char *) metad + sizeof(BTMetaPageData)) - (char *) page; @@ -241,7 +242,7 @@ _bt_getroot(Relation rel, int access) XLogBeginInsert(); XLogRegisterBuffer(0, rootbuf, REGBUF_WILL_INIT); - XLogRegisterBuffer(2, metabuf, REGBUF_WILL_INIT); + XLogRegisterBuffer(2, metabuf, REGBUF_WILL_INIT | REGBUF_STANDARD); md.root = rootblkno; md.level = 0; @@ -1827,7 +1828,7 @@ _bt_unlink_halfdead_page(Relation rel, Buffer leafbuf, bool *rightsib_empty) if (BufferIsValid(metabuf)) { - XLogRegisterBuffer(4, metabuf, REGBUF_WILL_INIT); + XLogRegisterBuffer(4, metabuf, REGBUF_WILL_INIT | REGBUF_STANDARD); xlmeta.root = metad->btm_root; xlmeta.level = metad->btm_level; diff --git a/src/backend/access/nbtree/nbtree.c b/src/backend/access/nbtree/nbtree.c index 3dbafdd6fc..399e6a1ae5 100644 --- a/src/backend/access/nbtree/nbtree.c +++ b/src/backend/access/nbtree/nbtree.c @@ -298,7 +298,7 @@ btbuildempty(Relation index) smgrwrite(index->rd_smgr, INIT_FORKNUM, BTREE_METAPAGE, (char *) metapage, true); log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM, - BTREE_METAPAGE, metapage, false); + BTREE_METAPAGE, metapage, true); /* * An immediate sync is required even if we xlog'd the page, because the diff --git a/src/backend/access/nbtree/nbtxlog.c b/src/backend/access/nbtree/nbtxlog.c index 82337f8ef2..7250b4f0b8 100644 --- a/src/backend/access/nbtree/nbtxlog.c +++ b/src/backend/access/nbtree/nbtxlog.c @@ -107,8 +107,9 @@ _bt_restore_meta(XLogReaderState *record, uint8 block_id) pageop->btpo_flags = BTP_META; /* - * Set pd_lower just past the end of the metadata. This is not essential - * but it makes the page look compressible to xlog.c. + * Set pd_lower just past the end of the metadata. This is essential, + * because without doing so, metadata will be lost if xlog.c compresses + * the page. */ ((PageHeader) metapg)->pd_lower = ((char *) md + sizeof(BTMetaPageData)) - (char *) metapg;