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First cut at recycling space in btree indexes. Still some rough edges

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to fix, but it seems to basically work...
This commit is contained in:
Tom Lane
2003-02-23 06:17:13 +00:00
parent 27854915b9
commit 88dc31e3f2
8 changed files with 745 additions and 32 deletions
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175
src/backend/access/nbtree/nbtxlog.c
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@@ -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);