From d5357e311be2aa71f842335f8684a7600493044c Mon Sep 17 00:00:00 2001 From: amit Date: Mon, 26 Jun 2017 15:13:32 +0900 Subject: [PATCH 2/3] Set pd_lower correctly in the BRIN index metapage Also tell xlog.c to treat the metapage like a standard page, so any hole in it is compressed. --- src/backend/access/brin/brin.c | 4 ++-- src/backend/access/brin/brin_pageops.c | 9 +++++++++ src/backend/access/brin/brin_xlog.c | 9 +++++++-- 3 files changed, 18 insertions(+), 4 deletions(-) diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c index b3aa6d1ced..e6909d7aea 100644 --- a/src/backend/access/brin/brin.c +++ b/src/backend/access/brin/brin.c @@ -685,7 +685,7 @@ brinbuild(Relation heap, Relation index, IndexInfo *indexInfo) XLogBeginInsert(); XLogRegisterData((char *) &xlrec, SizeOfBrinCreateIdx); - XLogRegisterBuffer(0, meta, REGBUF_WILL_INIT); + XLogRegisterBuffer(0, meta, REGBUF_WILL_INIT | REGBUF_STANDARD); recptr = XLogInsert(RM_BRIN_ID, XLOG_BRIN_CREATE_INDEX); @@ -742,7 +742,7 @@ brinbuildempty(Relation index) brin_metapage_init(BufferGetPage(metabuf), BrinGetPagesPerRange(index), BRIN_CURRENT_VERSION); MarkBufferDirty(metabuf); - log_newpage_buffer(metabuf, false); + log_newpage_buffer(metabuf, true); END_CRIT_SECTION(); UnlockReleaseBuffer(metabuf); diff --git a/src/backend/access/brin/brin_pageops.c b/src/backend/access/brin/brin_pageops.c index 80f803e438..117322ed17 100644 --- a/src/backend/access/brin/brin_pageops.c +++ b/src/backend/access/brin/brin_pageops.c @@ -491,6 +491,15 @@ brin_metapage_init(Page page, BlockNumber pagesPerRange, uint16 version) * revmap page to be created when the index is. */ metadata->lastRevmapPage = 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, as long as the + * buffer containing the page is passed to XLogRegisterBuffer() as a + * REGBUF_STANDARD page. + */ + ((PageHeader) page)->pd_lower = + ((char *) metadata + sizeof(BrinMetaPageData)) - (char *) page; } /* diff --git a/src/backend/access/brin/brin_xlog.c b/src/backend/access/brin/brin_xlog.c index dff7198a39..1309d44b04 100644 --- a/src/backend/access/brin/brin_xlog.c +++ b/src/backend/access/brin/brin_xlog.c @@ -331,14 +331,19 @@ void brin_mask(char *pagedata, BlockNumber blkno) { Page page = (Page) pagedata; + PageHeader pagehdr = (PageHeader) page; mask_page_lsn(page); mask_page_hint_bits(page); - if (BRIN_IS_REGULAR_PAGE(page)) + /* + * Regular brin pages contain unused space which needs to be masked. + * Similarly for meta pages, but only if pd_lower has been set. + */ + if (BRIN_IS_REGULAR_PAGE(page) || + (BRIN_IS_META_PAGE(page) && pagehdr->pd_lower != 0)) { - /* Regular brin pages contain unused space which needs to be masked. */ mask_unused_space(page); } } -- 2.11.0