* BTree-specific page management code for the Postgres btree access
* method.
*
- * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/access/nbtree/nbtpage.c,v 1.114 2009/12/19 01:32:33 sriggs Exp $
+ * src/backend/access/nbtree/nbtpage.c
*
* NOTES
* Postgres btree pages look like ordinary relation pages. The opaque
#include "storage/freespace.h"
#include "storage/indexfsm.h"
#include "storage/lmgr.h"
+#include "storage/predicate.h"
#include "utils/inval.h"
#include "utils/snapmgr.h"
MarkBufferDirty(metabuf);
/* XLOG stuff */
- if (!rel->rd_istemp)
+ if (RelationNeedsWAL(rel))
{
xl_btree_newroot xlrec;
XLogRecPtr recptr;
}
/*
+ * Log the reuse of a page from the FSM.
+ */
+static void
+_bt_log_reuse_page(Relation rel, BlockNumber blkno, TransactionId latestRemovedXid)
+{
+ if (!RelationNeedsWAL(rel))
+ return;
+
+ /* No ereport(ERROR) until changes are logged */
+ START_CRIT_SECTION();
+
+ /*
+ * We don't do MarkBufferDirty here because we're about initialise the
+ * page, and nobody else can see it yet.
+ */
+
+ /* XLOG stuff */
+ {
+ XLogRecData rdata[1];
+ xl_btree_reuse_page xlrec_reuse;
+
+ xlrec_reuse.node = rel->rd_node;
+ xlrec_reuse.block = blkno;
+ xlrec_reuse.latestRemovedXid = latestRemovedXid;
+ rdata[0].data = (char *) &xlrec_reuse;
+ rdata[0].len = SizeOfBtreeReusePage;
+ rdata[0].buffer = InvalidBuffer;
+ rdata[0].next = NULL;
+
+ XLogInsert(RM_BTREE_ID, XLOG_BTREE_REUSE_PAGE, rdata);
+
+ /*
+ * We don't do PageSetLSN or PageSetTLI here because we're about
+ * initialise the page, so no need.
+ */
+ }
+
+ END_CRIT_SECTION();
+}
+
+/*
* _bt_getbuf() -- Get a buffer by block number for read or write.
*
* blkno == P_NEW means to get an unallocated index page. The page
page = BufferGetPage(buf);
if (_bt_page_recyclable(page))
{
+ /*
+ * If we are generating WAL for Hot Standby then create a
+ * WAL record that will allow us to conflict with queries
+ * running on standby.
+ */
+ if (XLogStandbyInfoActive())
+ {
+ BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+
+ _bt_log_reuse_page(rel, blkno, opaque->btpo.xact);
+ }
+
/* Okay to use page. Re-initialize and return it */
_bt_pageinit(page, BufferGetPageSize(buf));
return buf;
_bt_page_recyclable(Page page)
{
BTPageOpaque opaque;
+ TransactionId cutoff;
/*
* It's possible to find an all-zeroes page in an index --- for example, a
/*
* Otherwise, recycle if deleted and too old to have any processes
- * interested in it.
+ * interested in it. If we are generating records for Hot Standby
+ * defer page recycling until RecentGlobalXmin to respect user
+ * controls specified by vacuum_defer_cleanup_age or hot_standby_feedback.
*/
+ if (XLogStandbyInfoActive())
+ cutoff = RecentGlobalXmin;
+ else
+ cutoff = RecentXmin;
+
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
if (P_ISDELETED(opaque) &&
- TransactionIdPrecedesOrEquals(opaque->btpo.xact, RecentXmin))
+ TransactionIdPrecedesOrEquals(opaque->btpo.xact, cutoff))
return true;
return false;
}
* ensure correct locking.
*/
void
-_bt_delitems(Relation rel, Buffer buf,
- OffsetNumber *itemnos, int nitems, bool isVacuum,
- BlockNumber lastBlockVacuumed)
+_bt_delitems_vacuum(Relation rel, Buffer buf,
+ OffsetNumber *itemnos, int nitems, BlockNumber lastBlockVacuumed)
{
Page page = BufferGetPage(buf);
BTPageOpaque opaque;
- Assert(isVacuum || lastBlockVacuumed == 0);
-
/* No ereport(ERROR) until changes are logged */
START_CRIT_SECTION();
MarkBufferDirty(buf);
/* XLOG stuff */
- if (!rel->rd_istemp)
+ if (RelationNeedsWAL(rel))
{
XLogRecPtr recptr;
XLogRecData rdata[2];
- if (isVacuum)
- {
- xl_btree_vacuum xlrec_vacuum;
- xlrec_vacuum.node = rel->rd_node;
- xlrec_vacuum.block = BufferGetBlockNumber(buf);
-
- xlrec_vacuum.lastBlockVacuumed = lastBlockVacuumed;
- rdata[0].data = (char *) &xlrec_vacuum;
- rdata[0].len = SizeOfBtreeVacuum;
- }
- else
- {
- xl_btree_delete xlrec_delete;
- xlrec_delete.node = rel->rd_node;
- xlrec_delete.block = BufferGetBlockNumber(buf);
+ xl_btree_vacuum xlrec_vacuum;
- /*
- * XXX: We would like to set an accurate latestRemovedXid, but
- * there is no easy way of obtaining a useful value. So we punt
- * and store InvalidTransactionId, which forces the standby to
- * wait for/cancel all currently running transactions.
- */
- xlrec_delete.latestRemovedXid = InvalidTransactionId;
- rdata[0].data = (char *) &xlrec_delete;
- rdata[0].len = SizeOfBtreeDelete;
- }
+ xlrec_vacuum.node = rel->rd_node;
+ xlrec_vacuum.block = BufferGetBlockNumber(buf);
+ xlrec_vacuum.lastBlockVacuumed = lastBlockVacuumed;
+ rdata[0].data = (char *) &xlrec_vacuum;
+ rdata[0].len = SizeOfBtreeVacuum;
rdata[0].buffer = InvalidBuffer;
rdata[0].next = &(rdata[1]);
rdata[1].buffer_std = true;
rdata[1].next = NULL;
- if (isVacuum)
- recptr = XLogInsert(RM_BTREE_ID, XLOG_BTREE_VACUUM, rdata);
- else
- recptr = XLogInsert(RM_BTREE_ID, XLOG_BTREE_DELETE, rdata);
+ recptr = XLogInsert(RM_BTREE_ID, XLOG_BTREE_VACUUM, rdata);
+
+ PageSetLSN(page, recptr);
+ PageSetTLI(page, ThisTimeLineID);
+ }
+
+ END_CRIT_SECTION();
+}
+
+void
+_bt_delitems_delete(Relation rel, Buffer buf,
+ OffsetNumber *itemnos, int nitems, Relation heapRel)
+{
+ Page page = BufferGetPage(buf);
+ BTPageOpaque opaque;
+
+ Assert(nitems > 0);
+
+ /* No ereport(ERROR) until changes are logged */
+ START_CRIT_SECTION();
+
+ /* Fix the page */
+ PageIndexMultiDelete(page, itemnos, nitems);
+
+ /*
+ * We can clear the vacuum cycle ID since this page has certainly been
+ * processed by the current vacuum scan.
+ */
+ opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+ opaque->btpo_cycleid = 0;
+
+ /*
+ * Mark the page as not containing any LP_DEAD items. This is not
+ * certainly true (there might be some that have recently been marked, but
+ * weren't included in our target-item list), but it will almost always be
+ * true and it doesn't seem worth an additional page scan to check it.
+ * Remember that BTP_HAS_GARBAGE is only a hint anyway.
+ */
+ opaque->btpo_flags &= ~BTP_HAS_GARBAGE;
+
+ MarkBufferDirty(buf);
+
+ /* XLOG stuff */
+ if (RelationNeedsWAL(rel))
+ {
+ XLogRecPtr recptr;
+ XLogRecData rdata[3];
+
+ xl_btree_delete xlrec_delete;
+
+ xlrec_delete.node = rel->rd_node;
+ xlrec_delete.hnode = heapRel->rd_node;
+ xlrec_delete.block = BufferGetBlockNumber(buf);
+ xlrec_delete.nitems = nitems;
+
+ rdata[0].data = (char *) &xlrec_delete;
+ rdata[0].len = SizeOfBtreeDelete;
+ rdata[0].buffer = InvalidBuffer;
+ rdata[0].next = &(rdata[1]);
+
+ /*
+ * We need the target-offsets array whether or not we store the to
+ * allow us to find the latestRemovedXid on a standby server.
+ */
+ rdata[1].data = (char *) itemnos;
+ rdata[1].len = nitems * sizeof(OffsetNumber);
+ rdata[1].buffer = InvalidBuffer;
+ rdata[1].next = &(rdata[2]);
+
+ rdata[2].data = NULL;
+ rdata[2].len = 0;
+ rdata[2].buffer = buf;
+ rdata[2].buffer_std = true;
+ rdata[2].next = NULL;
+
+ recptr = XLogInsert(RM_BTREE_ID, XLOG_BTREE_DELETE, rdata);
PageSetLSN(page, recptr);
PageSetTLI(page, ThisTimeLineID);
* frequently.
*/
int
-_bt_pagedel(Relation rel, Buffer buf, BTStack stack, bool vacuum_full)
+_bt_pagedel(Relation rel, Buffer buf, BTStack stack)
{
int result;
BlockNumber target,
*/
rightsib = opaque->btpo_next;
rbuf = _bt_getbuf(rel, rightsib, BT_WRITE);
+ page = BufferGetPage(rbuf);
+ opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+ if (opaque->btpo_prev != target)
+ elog(ERROR, "right sibling's left-link doesn't match: "
+ "block %u links to %u instead of expected %u in index \"%s\"",
+ rightsib, opaque->btpo_prev, target,
+ RelationGetRelationName(rel));
+
+ /*
+ * Any insert which would have gone on the target block will now go to the
+ * right sibling block.
+ */
+ PredicateLockPageCombine(rel, target, rightsib);
/*
* Next find and write-lock the current parent of the target page. This is
}
/*
+ * Check that the parent-page index items we're about to delete/overwrite
+ * contain what we expect. This can fail if the index has become corrupt
+ * for some reason. We want to throw any error before entering the
+ * critical section --- otherwise it'd be a PANIC.
+ *
+ * The test on the target item is just an Assert because _bt_getstackbuf
+ * should have guaranteed it has the expected contents. The test on the
+ * next-child downlink is known to sometimes fail in the field, though.
+ */
+ page = BufferGetPage(pbuf);
+ opaque = (BTPageOpaque) PageGetSpecialPointer(page);
+
+#ifdef USE_ASSERT_CHECKING
+ itemid = PageGetItemId(page, poffset);
+ itup = (IndexTuple) PageGetItem(page, itemid);
+ Assert(ItemPointerGetBlockNumber(&(itup->t_tid)) == target);
+#endif
+
+ if (!parent_half_dead)
+ {
+ OffsetNumber nextoffset;
+
+ nextoffset = OffsetNumberNext(poffset);
+ itemid = PageGetItemId(page, nextoffset);
+ itup = (IndexTuple) PageGetItem(page, itemid);
+ if (ItemPointerGetBlockNumber(&(itup->t_tid)) != rightsib)
+ elog(ERROR, "right sibling %u of block %u is not next child %u of block %u in index \"%s\"",
+ rightsib, target, ItemPointerGetBlockNumber(&(itup->t_tid)),
+ parent, RelationGetRelationName(rel));
+ }
+
+ /*
* Here we begin doing the deletion.
*/
* to copy the right sibling's downlink over the target downlink, and then
* delete the following item.
*/
- page = BufferGetPage(pbuf);
- opaque = (BTPageOpaque) PageGetSpecialPointer(page);
if (parent_half_dead)
{
PageIndexTupleDelete(page, poffset);
itemid = PageGetItemId(page, poffset);
itup = (IndexTuple) PageGetItem(page, itemid);
- Assert(ItemPointerGetBlockNumber(&(itup->t_tid)) == target);
ItemPointerSet(&(itup->t_tid), rightsib, P_HIKEY);
nextoffset = OffsetNumberNext(poffset);
- /* This part is just for double-checking */
- itemid = PageGetItemId(page, nextoffset);
- itup = (IndexTuple) PageGetItem(page, itemid);
- if (ItemPointerGetBlockNumber(&(itup->t_tid)) != rightsib)
- elog(PANIC, "right sibling %u of block %u is not next child of %u in index \"%s\"",
- rightsib, target, BufferGetBlockNumber(pbuf),
- RelationGetRelationName(rel));
PageIndexTupleDelete(page, nextoffset);
}
/*
* Update siblings' side-links. Note the target page's side-links will
- * continue to point to the siblings.
+ * continue to point to the siblings. Asserts here are just rechecking
+ * things we already verified above.
*/
if (BufferIsValid(lbuf))
{
/*
* Mark the page itself deleted. It can be recycled when all current
- * transactions are gone; or immediately if we're doing VACUUM FULL.
+ * transactions are gone.
*/
page = BufferGetPage(buf);
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
opaque->btpo_flags &= ~BTP_HALF_DEAD;
opaque->btpo_flags |= BTP_DELETED;
- opaque->btpo.xact =
- vacuum_full ? FrozenTransactionId : ReadNewTransactionId();
+ opaque->btpo.xact = ReadNewTransactionId();
/* And update the metapage, if needed */
if (BufferIsValid(metabuf))
MarkBufferDirty(lbuf);
/* XLOG stuff */
- if (!rel->rd_istemp)
+ if (RelationNeedsWAL(rel))
{
xl_btree_delete_page xlrec;
xl_btree_metadata xlmeta;
xlrec.deadblk = target;
xlrec.leftblk = leftsib;
xlrec.rightblk = rightsib;
+ xlrec.btpo_xact = opaque->btpo.xact;
rdata[0].data = (char *) &xlrec;
rdata[0].len = SizeOfBtreeDeletePage;
{
/* recursive call will release pbuf */
_bt_relbuf(rel, rbuf);
- result = _bt_pagedel(rel, pbuf, stack->bts_parent, vacuum_full) + 1;
+ result = _bt_pagedel(rel, pbuf, stack->bts_parent) + 1;
_bt_relbuf(rel, buf);
}
else if (parent_one_child && rightsib_empty)
_bt_relbuf(rel, pbuf);
_bt_relbuf(rel, buf);
/* recursive call will release rbuf */
- result = _bt_pagedel(rel, rbuf, stack, vacuum_full) + 1;
+ result = _bt_pagedel(rel, rbuf, stack) + 1;
}
else
{
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