First cut at recycling space in btree indexes. Still some rough edges
to fix, but it seems to basically work...
This commit is contained in:
Tom Lane
parent
27854915b9
commit
88dc31e3f2
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@ -9,7 +9,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/access/common/indextuple.c,v 1.63 2002/11/13 00:39:46 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/access/common/indextuple.c,v 1.64 2003/02/23 06:17:12 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -394,17 +394,16 @@ nocache_index_getattr(IndexTuple tup,
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}
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/*
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* Copies source into target. If *target == NULL, we palloc space; otherwise
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* we assume we have space that is already palloc'ed.
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* Create a palloc'd copy of an index tuple.
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*/
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void
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CopyIndexTuple(IndexTuple source, IndexTuple *target)
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IndexTuple
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CopyIndexTuple(IndexTuple source)
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{
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IndexTuple result;
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Size size;
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size = IndexTupleSize(source);
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if (*target == NULL)
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*target = (IndexTuple) palloc(size);
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memmove((char *) *target, (char *) source, size);
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result = (IndexTuple) palloc(size);
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memcpy(result, source, size);
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return result;
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}
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@ -8,7 +8,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.98 2003/02/22 00:45:03 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.99 2003/02/23 06:17:13 tgl Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -58,7 +58,6 @@ static OffsetNumber _bt_findsplitloc(Relation rel, Page page,
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static void _bt_checksplitloc(FindSplitData *state, OffsetNumber firstright,
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int leftfree, int rightfree,
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bool newitemonleft, Size firstrightitemsz);
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static Buffer _bt_getstackbuf(Relation rel, BTStack stack, int access);
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static void _bt_pgaddtup(Relation rel, Page page,
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Size itemsize, BTItem btitem,
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OffsetNumber itup_off, const char *where);
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@ -666,7 +665,6 @@ _bt_split(Relation rel, Buffer buf, OffsetNumber firstright,
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rightoff;
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OffsetNumber maxoff;
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OffsetNumber i;
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BTItem lhikey;
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rbuf = _bt_getbuf(rel, P_NEW, BT_WRITE);
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origpage = BufferGetPage(buf);
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@ -730,7 +728,6 @@ _bt_split(Relation rel, Buffer buf, OffsetNumber firstright,
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itemsz = ItemIdGetLength(itemid);
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item = (BTItem) PageGetItem(origpage, itemid);
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}
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lhikey = item;
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if (PageAddItem(leftpage, (Item) item, itemsz, leftoff,
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LP_USED) == InvalidOffsetNumber)
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elog(PANIC, "btree: failed to add hikey to the left sibling");
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@ -1262,7 +1259,7 @@ _bt_insert_parent(Relation rel,
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*
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* Returns InvalidBuffer if item not found (should not happen).
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*/
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static Buffer
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Buffer
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_bt_getstackbuf(Relation rel, BTStack stack, int access)
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{
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BlockNumber blkno;
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@ -9,7 +9,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtpage.c,v 1.60 2003/02/22 00:45:04 tgl Exp $
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* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtpage.c,v 1.61 2003/02/23 06:17:13 tgl Exp $
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*
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* NOTES
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* Postgres btree pages look like ordinary relation pages. The opaque
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@ -24,6 +24,7 @@
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#include "access/nbtree.h"
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#include "miscadmin.h"
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#include "storage/freespace.h"
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#include "storage/lmgr.h"
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@ -391,7 +392,38 @@ _bt_getbuf(Relation rel, BlockNumber blkno, int access)
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bool needLock;
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Page page;
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/* XXX soon: ask FSM about free space */
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Assert(access == BT_WRITE);
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/*
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* First see if the FSM knows of any free pages.
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*
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* We can't trust the FSM's report unreservedly; we have to check
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* that the page is still free. (For example, an already-free page
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* could have been re-used between the time the last VACUUM scanned
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* it and the time the VACUUM made its FSM updates.)
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*
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* The request size should be more than half of what btvacuumcleanup
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* logs as the per-page free space. We use BLCKSZ/2 and BLCKSZ-1
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* to try to get some use out of FSM's space management algorithm.
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* XXX this needs some more thought...
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*/
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for (;;)
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{
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blkno = GetPageWithFreeSpace(&rel->rd_node, BLCKSZ/2);
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if (blkno == InvalidBlockNumber)
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break;
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buf = ReadBuffer(rel, blkno);
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LockBuffer(buf, access);
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page = BufferGetPage(buf);
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if (_bt_page_recyclable(page))
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{
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/* Okay to use page. Re-initialize and return it */
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_bt_pageinit(page, BufferGetPageSize(buf));
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return buf;
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}
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elog(DEBUG1, "_bt_getbuf: FSM returned nonrecyclable page");
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_bt_relbuf(rel, buf);
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}
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/*
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* Extend the relation by one page.
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@ -487,6 +519,36 @@ _bt_pageinit(Page page, Size size)
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PageInit(page, size, sizeof(BTPageOpaqueData));
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}
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/*
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* _bt_page_recyclable() -- Is an existing page recyclable?
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*
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* This exists to make sure _bt_getbuf and btvacuumcleanup have the same
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* policy about whether a page is safe to re-use.
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*/
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bool
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_bt_page_recyclable(Page page)
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{
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BTPageOpaque opaque;
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/*
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* It's possible to find an all-zeroes page in an index --- for example,
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* a backend might successfully extend the relation one page and then
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* crash before it is able to make a WAL entry for adding the page.
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* If we find a zeroed page then reclaim it.
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*/
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if (PageIsNew(page))
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return true;
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/*
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* Otherwise, recycle if deleted and too old to have any processes
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* interested in it.
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*/
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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if (P_ISDELETED(opaque) &&
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TransactionIdPrecedesOrEquals(opaque->btpo.xact, RecentGlobalXmin))
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return true;
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return false;
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}
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/*
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* _bt_metaproot() -- Change the root page of the btree.
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*
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@ -605,3 +667,426 @@ _bt_itemdel(Relation rel, Buffer buf, ItemPointer tid)
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END_CRIT_SECTION();
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}
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/*
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* _bt_pagedel() -- Delete a page from the b-tree.
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*
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* This action unlinks the page from the b-tree structure, removing all
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* pointers leading to it --- but not touching its own left and right links.
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* The page cannot be physically reclaimed right away, since other processes
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* may currently be trying to follow links leading to the page; they have to
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* be allowed to use its right-link to recover. See nbtree/README.
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*
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* On entry, the target buffer must be pinned and read-locked. This lock and
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* pin will be dropped before exiting.
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*
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* Returns the number of pages successfully deleted (zero on failure; could
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* be more than one if parent blocks were deleted).
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*
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* NOTE: this leaks memory. Rather than trying to clean up everything
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* carefully, it's better to run it in a temp context that can be reset
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* frequently.
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*/
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int
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_bt_pagedel(Relation rel, Buffer buf, bool vacuum_full)
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{
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BlockNumber target,
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leftsib,
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rightsib,
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parent;
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OffsetNumber poffset,
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maxoff;
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uint32 targetlevel,
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ilevel;
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ItemId itemid;
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BTItem targetkey,
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btitem;
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ScanKey itup_scankey;
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BTStack stack;
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Buffer lbuf,
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rbuf,
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pbuf;
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bool parent_half_dead;
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bool parent_one_child;
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bool rightsib_empty;
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Buffer metabuf = InvalidBuffer;
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Page metapg = NULL;
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BTMetaPageData *metad = NULL;
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Page page;
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BTPageOpaque opaque;
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/*
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* We can never delete rightmost pages nor root pages. While at it,
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* check that page is not already deleted and is empty.
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*/
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page = BufferGetPage(buf);
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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if (P_RIGHTMOST(opaque) || P_ISROOT(opaque) || P_ISDELETED(opaque) ||
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P_FIRSTDATAKEY(opaque) <= PageGetMaxOffsetNumber(page))
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{
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_bt_relbuf(rel, buf);
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return 0;
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}
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/*
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* Save info about page, including a copy of its high key (it must
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* have one, being non-rightmost).
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*/
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target = BufferGetBlockNumber(buf);
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targetlevel = opaque->btpo.level;
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leftsib = opaque->btpo_prev;
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itemid = PageGetItemId(page, P_HIKEY);
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targetkey = CopyBTItem((BTItem) PageGetItem(page, itemid));
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/*
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* We need to get an approximate pointer to the page's parent page.
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* Use the standard search mechanism to search for the page's high key;
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* this will give us a link to either the current parent or someplace
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* to its left (if there are multiple equal high keys). To avoid
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* deadlocks, we'd better drop the target page lock first.
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*/
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_bt_relbuf(rel, buf);
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/* we need a scan key to do our search, so build one */
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itup_scankey = _bt_mkscankey(rel, &(targetkey->bti_itup));
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/* find the leftmost leaf page containing this key */
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stack = _bt_search(rel, rel->rd_rel->relnatts, itup_scankey,
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&lbuf, BT_READ);
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/* don't need a pin on that either */
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_bt_relbuf(rel, lbuf);
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/*
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* If we are trying to delete an interior page, _bt_search did more
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* than we needed. Locate the stack item pointing to our parent level.
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*/
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ilevel = 0;
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for (;;)
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{
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if (stack == NULL)
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elog(ERROR, "_bt_pagedel: not enough stack items");
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if (ilevel == targetlevel)
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break;
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stack = stack->bts_parent;
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ilevel++;
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}
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/*
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* We have to lock the pages we need to modify in the standard order:
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* moving right, then up. Else we will deadlock against other writers.
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*
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* So, we need to find and write-lock the current left sibling of the
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* target page. The sibling that was current a moment ago could have
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* split, so we may have to move right. This search could fail if
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* either the sibling or the target page was deleted by someone else
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* meanwhile; if so, give up. (Right now, that should never happen,
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* since page deletion is only done in VACUUM and there shouldn't be
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* multiple VACUUMs concurrently on the same table.)
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*/
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if (leftsib != P_NONE)
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{
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lbuf = _bt_getbuf(rel, leftsib, BT_WRITE);
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page = BufferGetPage(lbuf);
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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while (P_ISDELETED(opaque) || opaque->btpo_next != target)
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{
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/* step right one page */
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leftsib = opaque->btpo_next;
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_bt_relbuf(rel, lbuf);
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if (leftsib == P_NONE)
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{
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elog(LOG, "_bt_pagedel: no left sibling (concurrent deletion?)");
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return 0;
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}
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lbuf = _bt_getbuf(rel, leftsib, BT_WRITE);
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page = BufferGetPage(lbuf);
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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}
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}
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else
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lbuf = InvalidBuffer;
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/*
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* Next write-lock the target page itself. It should be okay to take just
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* a write lock not a superexclusive lock, since no scans would stop on an
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* empty page.
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*/
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buf = _bt_getbuf(rel, target, BT_WRITE);
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page = BufferGetPage(buf);
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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/*
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* Check page is still empty etc, else abandon deletion. The empty check
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* is necessary since someone else might have inserted into it while
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* we didn't have it locked; the others are just for paranoia's sake.
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*/
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if (P_RIGHTMOST(opaque) || P_ISROOT(opaque) || P_ISDELETED(opaque) ||
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P_FIRSTDATAKEY(opaque) <= PageGetMaxOffsetNumber(page))
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{
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_bt_relbuf(rel, buf);
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if (BufferIsValid(lbuf))
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_bt_relbuf(rel, lbuf);
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return 0;
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}
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if (opaque->btpo_prev != leftsib)
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elog(ERROR, "_bt_pagedel: left link changed unexpectedly");
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/*
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* And next write-lock the (current) right sibling.
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*/
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rightsib = opaque->btpo_next;
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rbuf = _bt_getbuf(rel, rightsib, BT_WRITE);
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/*
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* Next find and write-lock the current parent of the target page.
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* This is essentially the same as the corresponding step of splitting.
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*/
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ItemPointerSet(&(stack->bts_btitem.bti_itup.t_tid),
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target, P_HIKEY);
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pbuf = _bt_getstackbuf(rel, stack, BT_WRITE);
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if (pbuf == InvalidBuffer)
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elog(ERROR, "_bt_getstackbuf: my bits moved right off the end of the world!"
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"\n\tRecreate index %s.", RelationGetRelationName(rel));
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parent = stack->bts_blkno;
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poffset = stack->bts_offset;
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/*
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* If the target is the rightmost child of its parent, then we can't
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* delete, unless it's also the only child --- in which case the parent
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* changes to half-dead status.
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*/
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page = BufferGetPage(pbuf);
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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maxoff = PageGetMaxOffsetNumber(page);
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parent_half_dead = false;
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parent_one_child = false;
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if (poffset >= maxoff)
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{
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if (poffset == P_FIRSTDATAKEY(opaque))
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parent_half_dead = true;
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else
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{
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_bt_relbuf(rel, pbuf);
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_bt_relbuf(rel, rbuf);
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_bt_relbuf(rel, buf);
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if (BufferIsValid(lbuf))
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_bt_relbuf(rel, lbuf);
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return 0;
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}
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}
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else
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{
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/* Will there be exactly one child left in this parent? */
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if (OffsetNumberNext(P_FIRSTDATAKEY(opaque)) == maxoff)
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parent_one_child = true;
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}
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/*
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* If we are deleting the next-to-last page on the target's level,
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* then the rightsib is a candidate to become the new fast root.
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* (In theory, it might be possible to push the fast root even further
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* down, but the odds of doing so are slim, and the locking considerations
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* daunting.)
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*
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* We can safely acquire a lock on the metapage here --- see comments for
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* _bt_newroot().
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*/
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if (leftsib == P_NONE)
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{
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page = BufferGetPage(rbuf);
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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Assert(opaque->btpo.level == targetlevel);
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if (P_RIGHTMOST(opaque))
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{
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/* rightsib will be the only one left on the level */
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metabuf = _bt_getbuf(rel, BTREE_METAPAGE, BT_WRITE);
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metapg = BufferGetPage(metabuf);
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metad = BTPageGetMeta(metapg);
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/*
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* The expected case here is btm_fastlevel == targetlevel+1;
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* if the fastlevel is <= targetlevel, something is wrong, and we
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* choose to overwrite it to fix it.
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*/
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if (metad->btm_fastlevel > targetlevel+1)
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{
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/* no update wanted */
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_bt_relbuf(rel, metabuf);
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metabuf = InvalidBuffer;
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}
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}
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}
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/*
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* Here we begin doing the deletion.
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*/
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/* No elog(ERROR) until changes are logged */
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START_CRIT_SECTION();
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/*
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* Update parent. The normal case is a tad tricky because we want to
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* delete the target's downlink and the *following* key. Easiest way is
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* to copy the right sibling's downlink over the target downlink, and then
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* delete the following item.
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*/
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page = BufferGetPage(pbuf);
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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if (parent_half_dead)
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{
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PageIndexTupleDelete(page, poffset);
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opaque->btpo_flags |= BTP_HALF_DEAD;
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}
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else
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{
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OffsetNumber nextoffset;
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itemid = PageGetItemId(page, poffset);
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btitem = (BTItem) PageGetItem(page, itemid);
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Assert(ItemPointerGetBlockNumber(&(btitem->bti_itup.t_tid)) == target);
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ItemPointerSet(&(btitem->bti_itup.t_tid), rightsib, P_HIKEY);
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nextoffset = OffsetNumberNext(poffset);
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/* This part is just for double-checking */
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itemid = PageGetItemId(page, nextoffset);
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btitem = (BTItem) PageGetItem(page, itemid);
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if (ItemPointerGetBlockNumber(&(btitem->bti_itup.t_tid)) != rightsib)
|
||||
elog(PANIC, "_bt_pagedel: right sibling is not next child");
|
||||
|
||||
PageIndexTupleDelete(page, nextoffset);
|
||||
}
|
||||
|
||||
/*
|
||||
* Update siblings' side-links. Note the target page's side-links will
|
||||
* continue to point to the siblings.
|
||||
*/
|
||||
if (BufferIsValid(lbuf))
|
||||
{
|
||||
page = BufferGetPage(lbuf);
|
||||
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
|
||||
Assert(opaque->btpo_next == target);
|
||||
opaque->btpo_next = rightsib;
|
||||
}
|
||||
page = BufferGetPage(rbuf);
|
||||
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
|
||||
Assert(opaque->btpo_prev == target);
|
||||
opaque->btpo_prev = leftsib;
|
||||
rightsib_empty = (P_FIRSTDATAKEY(opaque) > PageGetMaxOffsetNumber(page));
|
||||
|
||||
/*
|
||||
* Mark the page itself deleted. It can be recycled when all current
|
||||
* transactions are gone; or immediately if we're doing VACUUM FULL.
|
||||
*/
|
||||
page = BufferGetPage(buf);
|
||||
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
|
||||
opaque->btpo_flags |= BTP_DELETED;
|
||||
opaque->btpo.xact =
|
||||
vacuum_full ? FrozenTransactionId : ReadNewTransactionId();
|
||||
|
||||
/* And update the metapage, if needed */
|
||||
if (BufferIsValid(metabuf))
|
||||
{
|
||||
metad->btm_fastroot = rightsib;
|
||||
metad->btm_fastlevel = targetlevel;
|
||||
}
|
||||
|
||||
/* XLOG stuff */
|
||||
if (!rel->rd_istemp)
|
||||
{
|
||||
xl_btree_delete_page xlrec;
|
||||
xl_btree_metadata xlmeta;
|
||||
uint8 xlinfo;
|
||||
XLogRecPtr recptr;
|
||||
XLogRecData rdata[5];
|
||||
XLogRecData *nextrdata;
|
||||
|
||||
xlrec.target.node = rel->rd_node;
|
||||
ItemPointerSet(&(xlrec.target.tid), parent, poffset);
|
||||
xlrec.deadblk = target;
|
||||
xlrec.leftblk = leftsib;
|
||||
xlrec.rightblk = rightsib;
|
||||
|
||||
rdata[0].buffer = InvalidBuffer;
|
||||
rdata[0].data = (char *) &xlrec;
|
||||
rdata[0].len = SizeOfBtreeDeletePage;
|
||||
rdata[0].next = nextrdata = &(rdata[1]);
|
||||
|
||||
if (BufferIsValid(metabuf))
|
||||
{
|
||||
xlmeta.root = metad->btm_root;
|
||||
xlmeta.level = metad->btm_level;
|
||||
xlmeta.fastroot = metad->btm_fastroot;
|
||||
xlmeta.fastlevel = metad->btm_fastlevel;
|
||||
|
||||
nextrdata->buffer = InvalidBuffer;
|
||||
nextrdata->data = (char *) &xlmeta;
|
||||
nextrdata->len = sizeof(xl_btree_metadata);
|
||||
nextrdata->next = nextrdata + 1;
|
||||
nextrdata++;
|
||||
xlinfo = XLOG_BTREE_DELETE_PAGE_META;
|
||||
}
|
||||
else
|
||||
xlinfo = XLOG_BTREE_DELETE_PAGE;
|
||||
|
||||
nextrdata->buffer = pbuf;
|
||||
nextrdata->data = NULL;
|
||||
nextrdata->len = 0;
|
||||
nextrdata->next = nextrdata + 1;
|
||||
nextrdata++;
|
||||
|
||||
nextrdata->buffer = rbuf;
|
||||
nextrdata->data = NULL;
|
||||
nextrdata->len = 0;
|
||||
nextrdata->next = NULL;
|
||||
|
||||
if (BufferIsValid(lbuf))
|
||||
{
|
||||
nextrdata->next = nextrdata + 1;
|
||||
nextrdata++;
|
||||
nextrdata->buffer = lbuf;
|
||||
nextrdata->data = NULL;
|
||||
nextrdata->len = 0;
|
||||
nextrdata->next = NULL;
|
||||
}
|
||||
|
||||
recptr = XLogInsert(RM_BTREE_ID, xlinfo, rdata);
|
||||
|
||||
if (BufferIsValid(metabuf))
|
||||
{
|
||||
PageSetLSN(metapg, recptr);
|
||||
PageSetSUI(metapg, ThisStartUpID);
|
||||
}
|
||||
page = BufferGetPage(pbuf);
|
||||
PageSetLSN(page, recptr);
|
||||
PageSetSUI(page, ThisStartUpID);
|
||||
page = BufferGetPage(rbuf);
|
||||
PageSetLSN(page, recptr);
|
||||
PageSetSUI(page, ThisStartUpID);
|
||||
page = BufferGetPage(buf);
|
||||
PageSetLSN(page, recptr);
|
||||
PageSetSUI(page, ThisStartUpID);
|
||||
if (BufferIsValid(lbuf))
|
||||
{
|
||||
page = BufferGetPage(lbuf);
|
||||
PageSetLSN(page, recptr);
|
||||
PageSetSUI(page, ThisStartUpID);
|
||||
}
|
||||
}
|
||||
|
||||
END_CRIT_SECTION();
|
||||
|
||||
/* Write and release buffers */
|
||||
if (BufferIsValid(metabuf))
|
||||
_bt_wrtbuf(rel, metabuf);
|
||||
_bt_wrtbuf(rel, pbuf);
|
||||
_bt_wrtbuf(rel, rbuf);
|
||||
_bt_wrtbuf(rel, buf);
|
||||
if (BufferIsValid(lbuf))
|
||||
_bt_wrtbuf(rel, lbuf);
|
||||
|
||||
/*
|
||||
* If parent became half dead, recurse to try to delete it. Otherwise,
|
||||
* if right sibling is empty and is now the last child of the parent,
|
||||
* recurse to try to delete it. (These cases cannot apply at the same
|
||||
* time, though the second case might itself recurse to the first.)
|
||||
*/
|
||||
if (parent_half_dead)
|
||||
{
|
||||
buf = _bt_getbuf(rel, parent, BT_READ);
|
||||
return _bt_pagedel(rel, buf, vacuum_full) + 1;
|
||||
}
|
||||
if (parent_one_child && rightsib_empty)
|
||||
{
|
||||
buf = _bt_getbuf(rel, rightsib, BT_READ);
|
||||
return _bt_pagedel(rel, buf, vacuum_full) + 1;
|
||||
}
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
|
|
|||
|
|
@ -12,7 +12,7 @@
|
|||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtree.c,v 1.96 2003/02/22 00:45:04 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtree.c,v 1.97 2003/02/23 06:17:13 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
|
|
@ -710,15 +710,16 @@ Datum
|
|||
btvacuumcleanup(PG_FUNCTION_ARGS)
|
||||
{
|
||||
Relation rel = (Relation) PG_GETARG_POINTER(0);
|
||||
#ifdef NOT_USED
|
||||
IndexVacuumCleanupInfo *info = (IndexVacuumCleanupInfo *) PG_GETARG_POINTER(1);
|
||||
#endif
|
||||
IndexBulkDeleteResult *stats = (IndexBulkDeleteResult *) PG_GETARG_POINTER(2);
|
||||
BlockNumber num_pages;
|
||||
BlockNumber blkno;
|
||||
PageFreeSpaceInfo *pageSpaces;
|
||||
int nFreePages,
|
||||
maxFreePages;
|
||||
BlockNumber pages_deleted = 0;
|
||||
MemoryContext mycontext;
|
||||
MemoryContext oldcontext;
|
||||
|
||||
Assert(stats != NULL);
|
||||
|
||||
|
|
@ -731,6 +732,13 @@ btvacuumcleanup(PG_FUNCTION_ARGS)
|
|||
pageSpaces = (PageFreeSpaceInfo *) palloc(maxFreePages * sizeof(PageFreeSpaceInfo));
|
||||
nFreePages = 0;
|
||||
|
||||
/* Create a temporary memory context to run _bt_pagedel in */
|
||||
mycontext = AllocSetContextCreate(CurrentMemoryContext,
|
||||
"_bt_pagedel",
|
||||
ALLOCSET_DEFAULT_MINSIZE,
|
||||
ALLOCSET_DEFAULT_INITSIZE,
|
||||
ALLOCSET_DEFAULT_MAXSIZE);
|
||||
|
||||
/*
|
||||
* Scan through all pages of index, except metapage. (Any pages added
|
||||
* after we start the scan will not be examined; this should be fine,
|
||||
|
|
@ -745,17 +753,53 @@ btvacuumcleanup(PG_FUNCTION_ARGS)
|
|||
buf = _bt_getbuf(rel, blkno, BT_READ);
|
||||
page = BufferGetPage(buf);
|
||||
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
|
||||
if (P_ISDELETED(opaque))
|
||||
if (_bt_page_recyclable(page))
|
||||
{
|
||||
/* XXX if safe-to-reclaim... */
|
||||
/* Okay to recycle this page */
|
||||
if (nFreePages < maxFreePages)
|
||||
{
|
||||
pageSpaces[nFreePages].blkno = blkno;
|
||||
/* The avail-space value is bogus, but must be < BLCKSZ */
|
||||
/* claimed avail-space must be < BLCKSZ */
|
||||
pageSpaces[nFreePages].avail = BLCKSZ-1;
|
||||
nFreePages++;
|
||||
}
|
||||
}
|
||||
else if ((opaque->btpo_flags & BTP_HALF_DEAD) ||
|
||||
P_FIRSTDATAKEY(opaque) > PageGetMaxOffsetNumber(page))
|
||||
{
|
||||
/* Empty, try to delete */
|
||||
int ndel;
|
||||
|
||||
/* Run pagedel in a temp context to avoid memory leakage */
|
||||
MemoryContextReset(mycontext);
|
||||
oldcontext = MemoryContextSwitchTo(mycontext);
|
||||
|
||||
ndel = _bt_pagedel(rel, buf, info->vacuum_full);
|
||||
pages_deleted += ndel;
|
||||
|
||||
/*
|
||||
* During VACUUM FULL it's okay to recycle deleted pages
|
||||
* immediately, since there can be no other transactions
|
||||
* scanning the index. Note that we will only recycle the
|
||||
* current page and not any parent pages that _bt_pagedel
|
||||
* might have recursed to; this seems reasonable in the name
|
||||
* of simplicity. (Trying to do otherwise would mean we'd
|
||||
* have to sort the list of recyclable pages we're building.)
|
||||
*/
|
||||
if (ndel && info->vacuum_full)
|
||||
{
|
||||
if (nFreePages < maxFreePages)
|
||||
{
|
||||
pageSpaces[nFreePages].blkno = blkno;
|
||||
/* claimed avail-space must be < BLCKSZ */
|
||||
pageSpaces[nFreePages].avail = BLCKSZ-1;
|
||||
nFreePages++;
|
||||
}
|
||||
}
|
||||
|
||||
MemoryContextSwitchTo(oldcontext);
|
||||
continue; /* pagedel released buffer */
|
||||
}
|
||||
_bt_relbuf(rel, buf);
|
||||
}
|
||||
|
||||
|
|
@ -768,6 +812,13 @@ btvacuumcleanup(PG_FUNCTION_ARGS)
|
|||
|
||||
pfree(pageSpaces);
|
||||
|
||||
MemoryContextDelete(mycontext);
|
||||
|
||||
if (pages_deleted > 0)
|
||||
elog(info->message_level, "Index %s: %u pages, deleted %u; %u now free",
|
||||
RelationGetRelationName(rel),
|
||||
num_pages, pages_deleted, nFreePages);
|
||||
|
||||
/* update statistics */
|
||||
stats->num_pages = num_pages;
|
||||
stats->pages_free = nFreePages;
|
||||
|
|
|
|||
|
|
@ -8,7 +8,7 @@
|
|||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtxlog.c,v 1.1 2003/02/21 00:06:21 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtxlog.c,v 1.2 2003/02/23 06:17:13 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
|
|
@ -403,6 +403,171 @@ btree_xlog_delete(bool redo, XLogRecPtr lsn, XLogRecord *record)
|
|||
UnlockAndWriteBuffer(buffer);
|
||||
}
|
||||
|
||||
static void
|
||||
btree_xlog_delete_page(bool redo, bool ismeta,
|
||||
XLogRecPtr lsn, XLogRecord *record)
|
||||
{
|
||||
xl_btree_delete_page *xlrec = (xl_btree_delete_page *) XLogRecGetData(record);
|
||||
Relation reln;
|
||||
BlockNumber parent;
|
||||
BlockNumber target;
|
||||
BlockNumber leftsib;
|
||||
BlockNumber rightsib;
|
||||
Buffer buffer;
|
||||
Page page;
|
||||
BTPageOpaque pageop;
|
||||
char *op = (redo) ? "redo" : "undo";
|
||||
|
||||
reln = XLogOpenRelation(redo, RM_BTREE_ID, xlrec->target.node);
|
||||
if (!RelationIsValid(reln))
|
||||
return;
|
||||
|
||||
parent = ItemPointerGetBlockNumber(&(xlrec->target.tid));
|
||||
target = xlrec->deadblk;
|
||||
leftsib = xlrec->leftblk;
|
||||
rightsib = xlrec->rightblk;
|
||||
|
||||
/* parent page */
|
||||
if (redo && !(record->xl_info & XLR_BKP_BLOCK_1))
|
||||
{
|
||||
buffer = XLogReadBuffer(false, reln, parent);
|
||||
if (!BufferIsValid(buffer))
|
||||
elog(PANIC, "btree_delete_page_redo: parent block unfound");
|
||||
page = (Page) BufferGetPage(buffer);
|
||||
pageop = (BTPageOpaque) PageGetSpecialPointer(page);
|
||||
if (PageIsNew((PageHeader) page))
|
||||
elog(PANIC, "btree_delete_page_redo: uninitialized parent page");
|
||||
if (XLByteLE(lsn, PageGetLSN(page)))
|
||||
{
|
||||
UnlockAndReleaseBuffer(buffer);
|
||||
}
|
||||
else
|
||||
{
|
||||
OffsetNumber poffset;
|
||||
|
||||
poffset = ItemPointerGetOffsetNumber(&(xlrec->target.tid));
|
||||
if (poffset >= PageGetMaxOffsetNumber(page))
|
||||
{
|
||||
Assert(poffset == P_FIRSTDATAKEY(pageop));
|
||||
PageIndexTupleDelete(page, poffset);
|
||||
pageop->btpo_flags |= BTP_HALF_DEAD;
|
||||
}
|
||||
else
|
||||
{
|
||||
ItemId itemid;
|
||||
BTItem btitem;
|
||||
OffsetNumber nextoffset;
|
||||
|
||||
itemid = PageGetItemId(page, poffset);
|
||||
btitem = (BTItem) PageGetItem(page, itemid);
|
||||
ItemPointerSet(&(btitem->bti_itup.t_tid), rightsib, P_HIKEY);
|
||||
nextoffset = OffsetNumberNext(poffset);
|
||||
PageIndexTupleDelete(page, nextoffset);
|
||||
}
|
||||
|
||||
PageSetLSN(page, lsn);
|
||||
PageSetSUI(page, ThisStartUpID);
|
||||
UnlockAndWriteBuffer(buffer);
|
||||
}
|
||||
}
|
||||
|
||||
/* Fix left-link of right sibling */
|
||||
if (redo && !(record->xl_info & XLR_BKP_BLOCK_2))
|
||||
{
|
||||
buffer = XLogReadBuffer(false, reln, rightsib);
|
||||
if (!BufferIsValid(buffer))
|
||||
elog(PANIC, "btree_delete_page_redo: lost right sibling");
|
||||
page = (Page) BufferGetPage(buffer);
|
||||
if (PageIsNew((PageHeader) page))
|
||||
elog(PANIC, "btree_delete_page_redo: uninitialized right sibling");
|
||||
if (XLByteLE(lsn, PageGetLSN(page)))
|
||||
{
|
||||
UnlockAndReleaseBuffer(buffer);
|
||||
}
|
||||
else
|
||||
{
|
||||
pageop = (BTPageOpaque) PageGetSpecialPointer(page);
|
||||
pageop->btpo_prev = leftsib;
|
||||
|
||||
PageSetLSN(page, lsn);
|
||||
PageSetSUI(page, ThisStartUpID);
|
||||
UnlockAndWriteBuffer(buffer);
|
||||
}
|
||||
}
|
||||
|
||||
/* Fix right-link of left sibling, if any */
|
||||
if (redo && !(record->xl_info & XLR_BKP_BLOCK_3))
|
||||
{
|
||||
if (leftsib != P_NONE)
|
||||
{
|
||||
buffer = XLogReadBuffer(false, reln, leftsib);
|
||||
if (!BufferIsValid(buffer))
|
||||
elog(PANIC, "btree_delete_page_redo: lost left sibling");
|
||||
page = (Page) BufferGetPage(buffer);
|
||||
if (PageIsNew((PageHeader) page))
|
||||
elog(PANIC, "btree_delete_page_redo: uninitialized left sibling");
|
||||
if (XLByteLE(lsn, PageGetLSN(page)))
|
||||
{
|
||||
UnlockAndReleaseBuffer(buffer);
|
||||
}
|
||||
else
|
||||
{
|
||||
pageop = (BTPageOpaque) PageGetSpecialPointer(page);
|
||||
pageop->btpo_next = rightsib;
|
||||
|
||||
PageSetLSN(page, lsn);
|
||||
PageSetSUI(page, ThisStartUpID);
|
||||
UnlockAndWriteBuffer(buffer);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* Rewrite target page as empty deleted page */
|
||||
buffer = XLogReadBuffer(false, reln, target);
|
||||
if (!BufferIsValid(buffer))
|
||||
elog(PANIC, "btree_delete_page_%s: lost target page", op);
|
||||
page = (Page) BufferGetPage(buffer);
|
||||
if (redo)
|
||||
_bt_pageinit(page, BufferGetPageSize(buffer));
|
||||
else if (PageIsNew((PageHeader) page))
|
||||
elog(PANIC, "btree_delete_page_undo: uninitialized target page");
|
||||
pageop = (BTPageOpaque) PageGetSpecialPointer(page);
|
||||
|
||||
if (redo)
|
||||
{
|
||||
pageop->btpo_prev = leftsib;
|
||||
pageop->btpo_next = rightsib;
|
||||
pageop->btpo.xact = FrozenTransactionId;
|
||||
pageop->btpo_flags = BTP_DELETED;
|
||||
|
||||
PageSetLSN(page, lsn);
|
||||
PageSetSUI(page, ThisStartUpID);
|
||||
UnlockAndWriteBuffer(buffer);
|
||||
}
|
||||
else
|
||||
{
|
||||
/* undo */
|
||||
if (XLByteLT(PageGetLSN(page), lsn))
|
||||
elog(PANIC, "btree_delete_page_undo: bad left sibling LSN");
|
||||
elog(PANIC, "btree_delete_page_undo: unimplemented");
|
||||
}
|
||||
|
||||
/* Update metapage if needed */
|
||||
if (redo) /* metapage changes not undoable */
|
||||
{
|
||||
if (ismeta)
|
||||
{
|
||||
xl_btree_metadata md;
|
||||
|
||||
memcpy(&md, (char *) xlrec + SizeOfBtreeDeletePage,
|
||||
sizeof(xl_btree_metadata));
|
||||
_bt_restore_meta(reln, lsn,
|
||||
md.root, md.level,
|
||||
md.fastroot, md.fastlevel);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
static void
|
||||
btree_xlog_newroot(bool redo, XLogRecPtr lsn, XLogRecord *record)
|
||||
{
|
||||
|
|
@ -534,8 +699,10 @@ btree_redo(XLogRecPtr lsn, XLogRecord *record)
|
|||
btree_xlog_delete(true, lsn, record);
|
||||
break;
|
||||
case XLOG_BTREE_DELETE_PAGE:
|
||||
btree_xlog_delete_page(true, false, lsn, record);
|
||||
break;
|
||||
case XLOG_BTREE_DELETE_PAGE_META:
|
||||
// ???
|
||||
btree_xlog_delete_page(true, true, lsn, record);
|
||||
break;
|
||||
case XLOG_BTREE_NEWROOT:
|
||||
btree_xlog_newroot(true, lsn, record);
|
||||
|
|
@ -583,8 +750,10 @@ btree_undo(XLogRecPtr lsn, XLogRecord *record)
|
|||
btree_xlog_delete(false, lsn, record);
|
||||
break;
|
||||
case XLOG_BTREE_DELETE_PAGE:
|
||||
btree_xlog_delete_page(false, false, lsn, record);
|
||||
break;
|
||||
case XLOG_BTREE_DELETE_PAGE_META:
|
||||
// ???
|
||||
btree_xlog_delete_page(false, true, lsn, record);
|
||||
break;
|
||||
case XLOG_BTREE_NEWROOT:
|
||||
btree_xlog_newroot(false, lsn, record);
|
||||
|
|
|
|||
|
|
@ -8,7 +8,7 @@
|
|||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/storage/freespace/freespace.c,v 1.14 2002/09/20 19:56:01 tgl Exp $
|
||||
* $Header: /cvsroot/pgsql/src/backend/storage/freespace/freespace.c,v 1.15 2003/02/23 06:17:13 tgl Exp $
|
||||
*
|
||||
*
|
||||
* NOTES:
|
||||
|
|
@ -681,7 +681,9 @@ free_chunk_chain(FSMChunk *fchunk)
|
|||
* Look to see if a page with at least the specified amount of space is
|
||||
* available in the given FSMRelation. If so, return its page number,
|
||||
* and advance the nextPage counter so that the next inquiry will return
|
||||
* a different page if possible. Return InvalidBlockNumber if no success.
|
||||
* a different page if possible; also update the entry to show that the
|
||||
* requested space is not available anymore. Return InvalidBlockNumber
|
||||
* if no success.
|
||||
*/
|
||||
static BlockNumber
|
||||
find_free_space(FSMRelation *fsmrel, Size spaceNeeded)
|
||||
|
|
@ -713,6 +715,12 @@ find_free_space(FSMRelation *fsmrel, Size spaceNeeded)
|
|||
/* Check the next page */
|
||||
if ((Size) curChunk->bytes[chunkRelIndex] >= spaceNeeded)
|
||||
{
|
||||
/*
|
||||
* Found what we want --- adjust the entry. In theory we could
|
||||
* delete the entry immediately if it drops below threshold,
|
||||
* but it seems better to wait till we next need space.
|
||||
*/
|
||||
curChunk->bytes[chunkRelIndex] -= (ItemLength) spaceNeeded;
|
||||
fsmrel->nextPage = pageIndex + 1;
|
||||
return curChunk->pages[chunkRelIndex];
|
||||
}
|
||||
|
|
|
|||
|
|
@ -7,7 +7,7 @@
|
|||
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* $Id: itup.h,v 1.36 2002/08/25 17:20:01 tgl Exp $
|
||||
* $Id: itup.h,v 1.37 2003/02/23 06:17:13 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
|
|
@ -133,11 +133,11 @@ typedef InsertIndexResultData *InsertIndexResult;
|
|||
)
|
||||
|
||||
|
||||
/* indextuple.h */
|
||||
/* routines in indextuple.c */
|
||||
extern IndexTuple index_formtuple(TupleDesc tupleDescriptor,
|
||||
Datum *value, char *null);
|
||||
extern Datum nocache_index_getattr(IndexTuple tup, int attnum,
|
||||
TupleDesc tupleDesc, bool *isnull);
|
||||
extern void CopyIndexTuple(IndexTuple source, IndexTuple *target);
|
||||
extern IndexTuple CopyIndexTuple(IndexTuple source);
|
||||
|
||||
#endif /* ITUP_H */
|
||||
|
|
|
|||
|
|
@ -7,7 +7,7 @@
|
|||
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
|
||||
* Portions Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
* $Id: nbtree.h,v 1.65 2003/02/22 00:45:05 tgl Exp $
|
||||
* $Id: nbtree.h,v 1.66 2003/02/23 06:17:13 tgl Exp $
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
|
|
@ -118,6 +118,8 @@ typedef struct BTItemData
|
|||
|
||||
typedef BTItemData *BTItem;
|
||||
|
||||
#define CopyBTItem(btitem) ((BTItem) CopyIndexTuple((IndexTuple) (btitem)))
|
||||
|
||||
/*
|
||||
* For XLOG: size without alignment. Sizeof works as long as
|
||||
* IndexTupleData has exactly 8 bytes.
|
||||
|
|
@ -434,6 +436,7 @@ extern Datum btvacuumcleanup(PG_FUNCTION_ARGS);
|
|||
*/
|
||||
extern InsertIndexResult _bt_doinsert(Relation rel, BTItem btitem,
|
||||
bool index_is_unique, Relation heapRel);
|
||||
extern Buffer _bt_getstackbuf(Relation rel, BTStack stack, int access);
|
||||
extern void _bt_insert_parent(Relation rel, Buffer buf, Buffer rbuf,
|
||||
BTStack stack, bool is_root, bool is_only);
|
||||
|
||||
|
|
@ -448,8 +451,10 @@ extern void _bt_relbuf(Relation rel, Buffer buf);
|
|||
extern void _bt_wrtbuf(Relation rel, Buffer buf);
|
||||
extern void _bt_wrtnorelbuf(Relation rel, Buffer buf);
|
||||
extern void _bt_pageinit(Page page, Size size);
|
||||
extern bool _bt_page_recyclable(Page page);
|
||||
extern void _bt_metaproot(Relation rel, BlockNumber rootbknum, uint32 level);
|
||||
extern void _bt_itemdel(Relation rel, Buffer buf, ItemPointer tid);
|
||||
extern int _bt_pagedel(Relation rel, Buffer buf, bool vacuum_full);
|
||||
|
||||
/*
|
||||
* prototypes for functions in nbtsearch.c
|
||||
|
|
@ -488,7 +493,6 @@ extern BTItem _bt_formitem(IndexTuple itup);
|
|||
/*
|
||||
* prototypes for functions in nbtsort.c
|
||||
*/
|
||||
|
||||
typedef struct BTSpool BTSpool; /* opaque type known only within nbtsort.c */
|
||||
|
||||
extern BTSpool *_bt_spoolinit(Relation index, bool isunique);
|
||||
|
|
|
|||
Loading…
Reference in New Issue