From 6741334ce5f3261b5e5caffa3914d4e1485fe5d8 Mon Sep 17 00:00:00 2001 From: amit Date: Fri, 23 Jun 2017 11:20:41 +0900 Subject: [PATCH 1/3] Set pd_lower correctly in the GIN metapage. Also tell xlog.c to treat the metapage like a standard page, so any hole in it is compressed. --- src/backend/access/gin/ginfast.c | 22 ++++++++++++++++++++-- src/backend/access/gin/gininsert.c | 4 ++-- src/backend/access/gin/ginutil.c | 19 ++++++++++++++++++- src/backend/access/gin/ginxlog.c | 25 ++++++++++--------------- 4 files changed, 50 insertions(+), 20 deletions(-) diff --git a/src/backend/access/gin/ginfast.c b/src/backend/access/gin/ginfast.c index 59e435465a..d96529cf72 100644 --- a/src/backend/access/gin/ginfast.c +++ b/src/backend/access/gin/ginfast.c @@ -399,6 +399,15 @@ ginHeapTupleFastInsert(GinState *ginstate, GinTupleCollector *collector) /* * Write metabuffer, make xlog entry */ + + /* + * Set pd_lower just past the end of the metadata. This is not essential + * but it makes the page look compressible to xlog.c, because we pass the + * buffer containing this page to XLogRegisterBuffer() as a page with + * standard layout. + */ + ((PageHeader) metapage)->pd_lower = + ((char *) metadata + sizeof(GinMetaPageData)) - (char *) metapage; MarkBufferDirty(metabuffer); if (needWal) @@ -407,7 +416,7 @@ ginHeapTupleFastInsert(GinState *ginstate, GinTupleCollector *collector) memcpy(&data.metadata, metadata, sizeof(GinMetaPageData)); - XLogRegisterBuffer(0, metabuffer, REGBUF_WILL_INIT); + XLogRegisterBuffer(0, metabuffer, REGBUF_WILL_INIT | REGBUF_STANDARD); XLogRegisterData((char *) &data, sizeof(ginxlogUpdateMeta)); recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_UPDATE_META_PAGE); @@ -572,6 +581,14 @@ shiftList(Relation index, Buffer metabuffer, BlockNumber newHead, metadata->nPendingHeapTuples = 0; } + /* + * Set pd_lower just past the end of the metadata. This is not + * essential but it makes the page look compressible to xlog.c, + * because we pass the buffer containing this page to + * XLogRegisterBuffer() as page with standard layout. + */ + ((PageHeader) metapage)->pd_lower = + ((char *) metadata + sizeof(GinMetaPageData)) - (char *) metapage; MarkBufferDirty(metabuffer); for (i = 0; i < data.ndeleted; i++) @@ -586,7 +603,8 @@ shiftList(Relation index, Buffer metabuffer, BlockNumber newHead, XLogRecPtr recptr; XLogBeginInsert(); - XLogRegisterBuffer(0, metabuffer, REGBUF_WILL_INIT); + XLogRegisterBuffer(0, metabuffer, + REGBUF_WILL_INIT | REGBUF_STANDARD); for (i = 0; i < data.ndeleted; i++) XLogRegisterBuffer(i + 1, buffers[i], REGBUF_WILL_INIT); diff --git a/src/backend/access/gin/gininsert.c b/src/backend/access/gin/gininsert.c index 5378011f50..c9aa4ee147 100644 --- a/src/backend/access/gin/gininsert.c +++ b/src/backend/access/gin/gininsert.c @@ -348,7 +348,7 @@ ginbuild(Relation heap, Relation index, IndexInfo *indexInfo) Page page; XLogBeginInsert(); - XLogRegisterBuffer(0, MetaBuffer, REGBUF_WILL_INIT); + XLogRegisterBuffer(0, MetaBuffer, REGBUF_WILL_INIT | REGBUF_STANDARD); XLogRegisterBuffer(1, RootBuffer, REGBUF_WILL_INIT); recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_CREATE_INDEX); @@ -447,7 +447,7 @@ ginbuildempty(Relation index) START_CRIT_SECTION(); GinInitMetabuffer(MetaBuffer); MarkBufferDirty(MetaBuffer); - log_newpage_buffer(MetaBuffer, false); + log_newpage_buffer(MetaBuffer, true); GinInitBuffer(RootBuffer, GIN_LEAF); MarkBufferDirty(RootBuffer); log_newpage_buffer(RootBuffer, false); diff --git a/src/backend/access/gin/ginutil.c b/src/backend/access/gin/ginutil.c index 136ea27718..d680849e9d 100644 --- a/src/backend/access/gin/ginutil.c +++ b/src/backend/access/gin/ginutil.c @@ -374,6 +374,15 @@ GinInitMetabuffer(Buffer b) metadata->nDataPages = 0; metadata->nEntries = 0; metadata->ginVersion = GIN_CURRENT_VERSION; + + /* + * Set pd_lower just past the end of the metadata. This is not essential + * but it makes the page look compressible to xlog.c, because we pass the + * buffer containing this page to XLogRegisterBuffer() as a page with + * standard layout. + */ + ((PageHeader) page)->pd_lower = + ((char *) metadata + sizeof(GinMetaPageData)) - (char *) page; } /* @@ -676,6 +685,14 @@ ginUpdateStats(Relation index, const GinStatsData *stats) metadata->nDataPages = stats->nDataPages; metadata->nEntries = stats->nEntries; + /* + * Set pd_lower just past the end of the metadata. This is not essential + * but it makes the page look compressible to xlog.c, because we pass the + * buffer containing this page to XLogRegisterBuffer() as page with + * standard layout. + */ + ((PageHeader) metapage)->pd_lower = + ((char *) metadata + sizeof(GinMetaPageData)) - (char *) metapage; MarkBufferDirty(metabuffer); if (RelationNeedsWAL(index)) @@ -690,7 +707,7 @@ ginUpdateStats(Relation index, const GinStatsData *stats) XLogBeginInsert(); XLogRegisterData((char *) &data, sizeof(ginxlogUpdateMeta)); - XLogRegisterBuffer(0, metabuffer, REGBUF_WILL_INIT); + XLogRegisterBuffer(0, metabuffer, REGBUF_WILL_INIT | REGBUF_STANDARD); recptr = XLogInsert(RM_GIN_ID, XLOG_GIN_UPDATE_META_PAGE); PageSetLSN(metapage, recptr); diff --git a/src/backend/access/gin/ginxlog.c b/src/backend/access/gin/ginxlog.c index 7ba04e324f..52c14ce42e 100644 --- a/src/backend/access/gin/ginxlog.c +++ b/src/backend/access/gin/ginxlog.c @@ -514,7 +514,7 @@ ginRedoUpdateMetapage(XLogReaderState *record) Assert(BufferGetBlockNumber(metabuffer) == GIN_METAPAGE_BLKNO); metapage = BufferGetPage(metabuffer); - GinInitPage(metapage, GIN_META, BufferGetPageSize(metabuffer)); + GinInitMetabuffer(metabuffer); memcpy(GinPageGetMeta(metapage), &data->metadata, sizeof(GinMetaPageData)); PageSetLSN(metapage, lsn); MarkBufferDirty(metabuffer); @@ -656,7 +656,7 @@ ginRedoDeleteListPages(XLogReaderState *record) Assert(BufferGetBlockNumber(metabuffer) == GIN_METAPAGE_BLKNO); metapage = BufferGetPage(metabuffer); - GinInitPage(metapage, GIN_META, BufferGetPageSize(metabuffer)); + GinInitMetabuffer(metabuffer); memcpy(GinPageGetMeta(metapage), &data->metadata, sizeof(GinMetaPageData)); PageSetLSN(metapage, lsn); @@ -768,6 +768,7 @@ void gin_mask(char *pagedata, BlockNumber blkno) { Page page = (Page) pagedata; + PageHeader pagehdr = (PageHeader) page; GinPageOpaque opaque; mask_page_lsn(page); @@ -776,18 +777,12 @@ gin_mask(char *pagedata, BlockNumber blkno) mask_page_hint_bits(page); /* - * GIN metapage doesn't use pd_lower/pd_upper. Other page types do. Hence, - * we need to apply masking for those pages. + * For GIN_DELETED page, the page is initialized to empty. Hence, mask + * the page content. For other pages, mask the hole if the pd_lower + * appears to have been set correctly. */ - if (opaque->flags != GIN_META) - { - /* - * For GIN_DELETED page, the page is initialized to empty. Hence, mask - * the page content. - */ - if (opaque->flags & GIN_DELETED) - mask_page_content(page); - else - mask_unused_space(page); - } + if (opaque->flags & GIN_DELETED) + mask_page_content(page); + else if (pagehdr->pd_lower > SizeOfPageHeaderData) + mask_unused_space(page); } -- 2.11.0