From e6a5b734d61171dee1df39137439cbd48ed56b44 Mon Sep 17 00:00:00 2001 From: amit Date: Mon, 26 Jun 2017 15:23:34 +0900 Subject: [PATCH 3/3] Set pd_lower correctly in the SP-GiST index metapage Also tell xlog.c to treat the metapage like a standard page, so any hole in it is compressed. --- src/backend/access/spgist/spginsert.c | 4 ++-- src/backend/access/spgist/spgutils.c | 9 +++++++++ src/backend/access/spgist/spgxlog.c | 8 +++----- 3 files changed, 14 insertions(+), 7 deletions(-) diff --git a/src/backend/access/spgist/spginsert.c b/src/backend/access/spgist/spginsert.c index e4b2c29b0e..80b82e1602 100644 --- a/src/backend/access/spgist/spginsert.c +++ b/src/backend/access/spgist/spginsert.c @@ -110,7 +110,7 @@ spgbuild(Relation heap, Relation index, IndexInfo *indexInfo) * Replay will re-initialize the pages, so don't take full pages * images. No other data to log. */ - XLogRegisterBuffer(0, metabuffer, REGBUF_WILL_INIT); + XLogRegisterBuffer(0, metabuffer, REGBUF_WILL_INIT | REGBUF_STANDARD); XLogRegisterBuffer(1, rootbuffer, REGBUF_WILL_INIT | REGBUF_STANDARD); XLogRegisterBuffer(2, nullbuffer, REGBUF_WILL_INIT | REGBUF_STANDARD); @@ -173,7 +173,7 @@ spgbuildempty(Relation index) smgrwrite(index->rd_smgr, INIT_FORKNUM, SPGIST_METAPAGE_BLKNO, (char *) page, true); log_newpage(&index->rd_smgr->smgr_rnode.node, INIT_FORKNUM, - SPGIST_METAPAGE_BLKNO, page, false); + SPGIST_METAPAGE_BLKNO, page, true); /* Likewise for the root page. */ SpGistInitPage(page, SPGIST_LEAF); diff --git a/src/backend/access/spgist/spgutils.c b/src/backend/access/spgist/spgutils.c index 22f64b0103..291a1ae571 100644 --- a/src/backend/access/spgist/spgutils.c +++ b/src/backend/access/spgist/spgutils.c @@ -534,6 +534,15 @@ SpGistInitMetapage(Page page) /* initialize last-used-page cache to empty */ for (i = 0; i < SPGIST_CACHED_PAGES; i++) metadata->lastUsedPages.cachedPage[i].blkno = InvalidBlockNumber; + + /* + * 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(SpGistMetaPageData)) - (char *) page; } /* diff --git a/src/backend/access/spgist/spgxlog.c b/src/backend/access/spgist/spgxlog.c index c440d21715..bf209416f2 100644 --- a/src/backend/access/spgist/spgxlog.c +++ b/src/backend/access/spgist/spgxlog.c @@ -1033,15 +1033,13 @@ void spg_mask(char *pagedata, BlockNumber blkno) { Page page = (Page) pagedata; + PageHeader pagehdr = (PageHeader) page; mask_page_lsn(page); mask_page_hint_bits(page); - /* - * Any SpGist page other than meta contains unused space which needs to be - * masked. - */ - if (!SpGistPageIsMeta(page)) + /* Mask the unused space, provided the page's pd_lower is set. */ + if (pagehdr->pd_lower != 0) mask_unused_space(page); } -- 2.11.0