From f12b1105e4a0c356083a8dbae81e6a2c11da7bbe Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Fri, 5 Apr 2019 22:01:51 -0700 Subject: [PATCH] Convert gist to compute page level xid horizon on primary. Author: Reviewed-By: Discussion: https://postgr.es/m/ Backpatch: --- src/backend/access/gist/gist.c | 8 +- src/backend/access/gist/gistxlog.c | 153 +------------------------ src/backend/access/rmgrdesc/gistdesc.c | 7 +- src/include/access/gist_private.h | 2 +- src/include/access/gistxlog.h | 3 +- src/include/access/xlog_internal.h | 2 +- 6 files changed, 18 insertions(+), 157 deletions(-) diff --git a/src/backend/access/gist/gist.c b/src/backend/access/gist/gist.c index 2db790c840c..769aca42e3b 100644 --- a/src/backend/access/gist/gist.c +++ b/src/backend/access/gist/gist.c @@ -1616,6 +1616,7 @@ gistprunepage(Relation rel, Page page, Buffer buffer, Relation heapRel) int ndeletable = 0; OffsetNumber offnum, maxoff; + TransactionId latestRemovedXid = InvalidTransactionId; Assert(GistPageIsLeaf(page)); @@ -1634,6 +1635,11 @@ gistprunepage(Relation rel, Page page, Buffer buffer, Relation heapRel) deletable[ndeletable++] = offnum; } + if (XLogStandbyInfoActive() && RelationNeedsWAL(rel)) + latestRemovedXid = + index_compute_xid_horizon_for_tuples(rel, heapRel, buffer, + deletable, ndeletable); + if (ndeletable > 0) { START_CRIT_SECTION(); @@ -1658,7 +1664,7 @@ gistprunepage(Relation rel, Page page, Buffer buffer, Relation heapRel) recptr = gistXLogDelete(buffer, deletable, ndeletable, - heapRel->rd_node); + latestRemovedXid); PageSetLSN(page, recptr); } diff --git a/src/backend/access/gist/gistxlog.c b/src/backend/access/gist/gistxlog.c index 4fb1855e890..503db34d863 100644 --- a/src/backend/access/gist/gistxlog.c +++ b/src/backend/access/gist/gistxlog.c @@ -165,152 +165,6 @@ gistRedoPageUpdateRecord(XLogReaderState *record) UnlockReleaseBuffer(buffer); } -/* - * Get the latestRemovedXid from the heap pages pointed at by the index - * tuples being deleted. See also btree_xlog_delete_get_latestRemovedXid, - * on which this function is based. - */ -static TransactionId -gistRedoDeleteRecordGetLatestRemovedXid(XLogReaderState *record) -{ - gistxlogDelete *xlrec = (gistxlogDelete *) XLogRecGetData(record); - OffsetNumber *todelete; - Buffer ibuffer, - hbuffer; - Page ipage, - hpage; - RelFileNode rnode; - BlockNumber blkno; - ItemId iitemid, - hitemid; - IndexTuple itup; - HeapTupleHeader htuphdr; - BlockNumber hblkno; - OffsetNumber hoffnum; - TransactionId latestRemovedXid = InvalidTransactionId; - int i; - - /* - * If there's nothing running on the standby we don't need to derive a - * full latestRemovedXid value, so use a fast path out of here. This - * returns InvalidTransactionId, and so will conflict with all HS - * transactions; but since we just worked out that that's zero people, - * it's OK. - * - * XXX There is a race condition here, which is that a new backend might - * start just after we look. If so, it cannot need to conflict, but this - * coding will result in throwing a conflict anyway. - */ - if (CountDBBackends(InvalidOid) == 0) - return latestRemovedXid; - - /* - * In what follows, we have to examine the previous state of the index - * page, as well as the heap page(s) it points to. This is only valid if - * WAL replay has reached a consistent database state; which means that - * the preceding check is not just an optimization, but is *necessary*. We - * won't have let in any user sessions before we reach consistency. - */ - if (!reachedConsistency) - elog(PANIC, "gistRedoDeleteRecordGetLatestRemovedXid: cannot operate with inconsistent data"); - - /* - * Get index page. If the DB is consistent, this should not fail, nor - * should any of the heap page fetches below. If one does, we return - * InvalidTransactionId to cancel all HS transactions. That's probably - * overkill, but it's safe, and certainly better than panicking here. - */ - XLogRecGetBlockTag(record, 0, &rnode, NULL, &blkno); - ibuffer = XLogReadBufferExtended(rnode, MAIN_FORKNUM, blkno, RBM_NORMAL); - if (!BufferIsValid(ibuffer)) - return InvalidTransactionId; - LockBuffer(ibuffer, BUFFER_LOCK_EXCLUSIVE); - ipage = (Page) BufferGetPage(ibuffer); - - /* - * Loop through the deleted index items to obtain the TransactionId from - * the heap items they point to. - */ - todelete = (OffsetNumber *) ((char *) xlrec + SizeOfGistxlogDelete); - - for (i = 0; i < xlrec->ntodelete; i++) - { - /* - * Identify the index tuple about to be deleted - */ - iitemid = PageGetItemId(ipage, todelete[i]); - itup = (IndexTuple) PageGetItem(ipage, iitemid); - - /* - * Locate the heap page that the index tuple points at - */ - hblkno = ItemPointerGetBlockNumber(&(itup->t_tid)); - hbuffer = XLogReadBufferExtended(xlrec->hnode, MAIN_FORKNUM, hblkno, RBM_NORMAL); - if (!BufferIsValid(hbuffer)) - { - UnlockReleaseBuffer(ibuffer); - return InvalidTransactionId; - } - LockBuffer(hbuffer, BUFFER_LOCK_SHARE); - hpage = (Page) BufferGetPage(hbuffer); - - /* - * Look up the heap tuple header that the index tuple points at by - * using the heap node supplied with the xlrec. We can't use - * heap_fetch, since it uses ReadBuffer rather than XLogReadBuffer. - * Note that we are not looking at tuple data here, just headers. - */ - hoffnum = ItemPointerGetOffsetNumber(&(itup->t_tid)); - hitemid = PageGetItemId(hpage, hoffnum); - - /* - * Follow any redirections until we find something useful. - */ - while (ItemIdIsRedirected(hitemid)) - { - hoffnum = ItemIdGetRedirect(hitemid); - hitemid = PageGetItemId(hpage, hoffnum); - CHECK_FOR_INTERRUPTS(); - } - - /* - * If the heap item has storage, then read the header and use that to - * set latestRemovedXid. - * - * Some LP_DEAD items may not be accessible, so we ignore them. - */ - if (ItemIdHasStorage(hitemid)) - { - htuphdr = (HeapTupleHeader) PageGetItem(hpage, hitemid); - - HeapTupleHeaderAdvanceLatestRemovedXid(htuphdr, &latestRemovedXid); - } - else if (ItemIdIsDead(hitemid)) - { - /* - * Conjecture: if hitemid is dead then it had xids before the xids - * marked on LP_NORMAL items. So we just ignore this item and move - * onto the next, for the purposes of calculating - * latestRemovedxids. - */ - } - else - Assert(!ItemIdIsUsed(hitemid)); - - UnlockReleaseBuffer(hbuffer); - } - - UnlockReleaseBuffer(ibuffer); - - /* - * If all heap tuples were LP_DEAD then we will be returning - * InvalidTransactionId here, which avoids conflicts. This matches - * existing logic which assumes that LP_DEAD tuples must already be older - * than the latestRemovedXid on the cleanup record that set them as - * LP_DEAD, hence must already have generated a conflict. - */ - return latestRemovedXid; -} /* * redo delete on gist index page to remove tuples marked as DEAD during index @@ -337,12 +191,11 @@ gistRedoDeleteRecord(XLogReaderState *record) */ if (InHotStandby) { - TransactionId latestRemovedXid = gistRedoDeleteRecordGetLatestRemovedXid(record); RelFileNode rnode; XLogRecGetBlockTag(record, 0, &rnode, NULL, NULL); - ResolveRecoveryConflictWithSnapshot(latestRemovedXid, rnode); + ResolveRecoveryConflictWithSnapshot(xldata->latestRemovedXid, rnode); } if (XLogReadBufferForRedo(record, 0, &buffer) == BLK_NEEDS_REDO) @@ -800,12 +653,12 @@ gistXLogUpdate(Buffer buffer, */ XLogRecPtr gistXLogDelete(Buffer buffer, OffsetNumber *todelete, int ntodelete, - RelFileNode hnode) + TransactionId latestRemovedXid) { gistxlogDelete xlrec; XLogRecPtr recptr; - xlrec.hnode = hnode; + xlrec.latestRemovedXid = latestRemovedXid; xlrec.ntodelete = ntodelete; XLogBeginInsert(); diff --git a/src/backend/access/rmgrdesc/gistdesc.c b/src/backend/access/rmgrdesc/gistdesc.c index eb308c72d6b..767864b58e6 100644 --- a/src/backend/access/rmgrdesc/gistdesc.c +++ b/src/backend/access/rmgrdesc/gistdesc.c @@ -33,8 +33,11 @@ out_gistxlogPageReuse(StringInfo buf, gistxlogPageReuse *xlrec) } static void -out_gistxlogDelete(StringInfo buf, gistxlogPageUpdate *xlrec) +out_gistxlogDelete(StringInfo buf, gistxlogDelete *xlrec) { + appendStringInfo(buf, "delete: latestRemovedXid %u, nitems: %u", + xlrec->latestRemovedXid, xlrec->ntodelete); + } static void @@ -66,7 +69,7 @@ gist_desc(StringInfo buf, XLogReaderState *record) out_gistxlogPageReuse(buf, (gistxlogPageReuse *) rec); break; case XLOG_GIST_DELETE: - out_gistxlogDelete(buf, (gistxlogPageUpdate *) rec); + out_gistxlogDelete(buf, (gistxlogDelete *) rec); break; case XLOG_GIST_PAGE_SPLIT: out_gistxlogPageSplit(buf, (gistxlogPageSplit *) rec); diff --git a/src/include/access/gist_private.h b/src/include/access/gist_private.h index 78e2e3fb312..ccf050cd62d 100644 --- a/src/include/access/gist_private.h +++ b/src/include/access/gist_private.h @@ -431,7 +431,7 @@ extern XLogRecPtr gistXLogUpdate(Buffer buffer, Buffer leftchild); extern XLogRecPtr gistXLogDelete(Buffer buffer, OffsetNumber *todelete, - int ntodelete, RelFileNode hnode); + int ntodelete, TransactionId latestRemovedXid); extern XLogRecPtr gistXLogSplit(bool page_is_leaf, SplitedPageLayout *dist, diff --git a/src/include/access/gistxlog.h b/src/include/access/gistxlog.h index 9990d97cbd3..e66b034d7b8 100644 --- a/src/include/access/gistxlog.h +++ b/src/include/access/gistxlog.h @@ -47,8 +47,7 @@ typedef struct gistxlogPageUpdate */ typedef struct gistxlogDelete { - RelFileNode hnode; /* RelFileNode of the heap the index currently - * points at */ + TransactionId latestRemovedXid; uint16 ntodelete; /* number of deleted offsets */ /* diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h index 8b1348c36db..39a474c4996 100644 --- a/src/include/access/xlog_internal.h +++ b/src/include/access/xlog_internal.h @@ -31,7 +31,7 @@ /* * Each page of XLOG file has a header like this: */ -#define XLOG_PAGE_MAGIC 0xD100 /* can be used as WAL version indicator */ +#define XLOG_PAGE_MAGIC 0xD101 /* can be used as WAL version indicator */ typedef struct XLogPageHeaderData { -- 2.21.0.dirty