mirror of
https://github.com/postgres/postgres.git
synced 2025-11-03 09:13:20 +03:00
Couple additional functions to fix tree at runtime.
Need in one more function to handle "my bits moved..." case. FixBTree is still FALSE.
This commit is contained in:
Vadim B. Mikheev
@@ -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 1.78 2001/01/29 07:28:16 vadim Exp $
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* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtinsert.c,v 1.79 2001/01/31 01:08:36 vadim Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@@ -37,7 +37,9 @@ typedef struct
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extern bool FixBTree;
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Buffer _bt_fixroot(Relation rel, Buffer oldrootbuf, bool release);
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static void _bt_fixtree(Relation rel, BlockNumber blkno, BTStack stack);
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static void _bt_fixtree(Relation rel, BlockNumber blkno);
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static BlockNumber _bt_fixlevel(Relation rel, Buffer buf, BlockNumber limit);
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static OffsetNumber _bt_getoff(Page page, BlockNumber blkno);
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static Buffer _bt_newroot(Relation rel, Buffer lbuf, Buffer rbuf);
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@@ -512,7 +514,7 @@ _bt_insertonpg(Relation rel,
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{
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blkno = lpageop->btpo_parent;
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_bt_relbuf(rel, buf, BT_WRITE);
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_bt_fixtree(rel, blkno, NULL);
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_bt_fixtree(rel, blkno);
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goto formres;
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}
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}
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@@ -561,6 +563,10 @@ _bt_insertonpg(Relation rel,
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pbuf = _bt_getstackbuf(rel, stack);
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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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/* Now we can write and unlock the children */
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_bt_wrtbuf(rel, rbuf);
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_bt_wrtbuf(rel, buf);
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@@ -1172,8 +1178,10 @@ _bt_getstackbuf(Relation rel, BTStack stack)
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}
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/* by here, the item we're looking for moved right at least one page */
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if (P_RIGHTMOST(opaque))
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elog(FATAL, "_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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{
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_bt_relbuf(rel, buf, BT_WRITE);
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return(InvalidBuffer);
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}
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blkno = opaque->btpo_next;
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_bt_relbuf(rel, buf, BT_WRITE);
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@@ -1450,6 +1458,7 @@ _bt_fixroot(Relation rel, Buffer oldrootbuf, bool release)
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/* give up left buffer */
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_bt_relbuf(rel, leftbuf, BT_WRITE);
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pfree(btitem);
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leftbuf = rightbuf;
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leftpage = rightpage;
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leftopaque = rightopaque;
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@@ -1477,10 +1486,318 @@ _bt_fixroot(Relation rel, Buffer oldrootbuf, bool release)
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return(rootbuf);
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}
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/*
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* Using blkno of leftmost page on a level inside tree this func
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* checks/fixes tree from this level up to the root page.
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*/
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static void
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_bt_fixtree(Relation rel, BlockNumber blkno, BTStack stack)
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_bt_fixtree(Relation rel, BlockNumber blkno)
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{
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elog(ERROR, "bt_fixtree: unimplemented , yet");
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Buffer buf;
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Page page;
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BTPageOpaque opaque;
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BlockNumber pblkno;
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elog(ERROR, "bt_fixtree: unimplemented , yet (need to recreate index)");
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for ( ; ; )
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{
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buf = _bt_getbuf(rel, blkno, BT_READ);
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page = BufferGetPage(buf);
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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if (! P_LEFTMOST(opaque) || P_ISLEAF(opaque))
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elog(ERROR, "bt_fixtree: invalid start page (need to recreate index)");
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pblkno = opaque->btpo_parent;
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/* check/fix entire level */
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_bt_fixlevel(rel, buf, InvalidBlockNumber);
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/*
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* No pins/locks are held here. Re-read start page if its
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* btpo_parent pointed to meta page else go up one level.
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*/
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if (pblkno == BTREE_METAPAGE)
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{
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buf = _bt_getbuf(rel, blkno, BT_WRITE);
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page = BufferGetPage(buf);
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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if (P_ISROOT(opaque))
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{
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/* Tree is Ok now */
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_bt_relbuf(rel, buf, BT_WRITE);
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return;
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}
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pblkno = opaque->btpo_parent;
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/* Call _bt_fixroot() if there is no upper level */
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if (pblkno == BTREE_METAPAGE)
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{
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buf = _bt_fixroot(rel, buf, true);
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_bt_relbuf(rel, buf, BT_WRITE);
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return;
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}
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/* Have to go up one level */
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_bt_relbuf(rel, buf, BT_WRITE);
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blkno = pblkno;
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}
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}
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}
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/*
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* Check/fix level starting from page in buffer buf up to block
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* limit on *child* level (or till rightmost child page if limit
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* is InvalidBlockNumber). Start buffer must be read locked.
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* No pins/locks are held on exit. Returns block number of last
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* visited/pointing-to-limit page on *check/fix* level.
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*/
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static BlockNumber
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_bt_fixlevel(Relation rel, Buffer buf, BlockNumber limit)
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{
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BlockNumber blkno = BufferGetBlockNumber(buf);
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BlockNumber pblkno = blkno;
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Page page;
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BTPageOpaque opaque;
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BlockNumber cblkno[3];
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OffsetNumber coff[3];
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Buffer cbuf[3];
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Page cpage[3];
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BTPageOpaque copaque[3];
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BTItem btitem;
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int cidx, i;
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bool goodbye = false;
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char tbuf[BLCKSZ];
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page = BufferGetPage(buf);
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/* copy page to temp storage */
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memmove(tbuf, page, PageGetPageSize(page));
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_bt_relbuf(rel, buf, BT_READ);
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page = (Page)tbuf;
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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/* Initialize first child data */
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coff[0] = P_FIRSTDATAKEY(opaque);
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if (coff[0] > PageGetMaxOffsetNumber(page))
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elog(ERROR, "bt_fixlevel: invalid maxoff on start page (need to recreate index)");
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btitem = (BTItem) PageGetItem(page, PageGetItemId(page, coff[0]));
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cblkno[0] = ItemPointerGetBlockNumber(&(btitem->bti_itup.t_tid));
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cbuf[0] = _bt_getbuf(rel, cblkno[0], BT_READ);
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cpage[0] = BufferGetPage(cbuf[0]);
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copaque[0] = (BTPageOpaque) PageGetSpecialPointer(cpage[0]);
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if (P_LEFTMOST(opaque) && ! P_LEFTMOST(copaque[0]))
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elog(ERROR, "bt_fixtlevel: non-leftmost child page of leftmost parent (need to recreate index)");
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/* caller should take care and avoid this */
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if (P_RIGHTMOST(copaque[0]))
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elog(ERROR, "bt_fixtlevel: invalid start child (need to recreate index)");
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for ( ; ; )
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{
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/*
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* Read up to 2 more child pages and look for pointers
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* to them in *saved* parent page
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*/
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coff[1] = coff[2] = InvalidOffsetNumber;
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for (cidx = 0; cidx < 2; )
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{
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cidx++;
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cblkno[cidx] = (copaque[cidx - 1])->btpo_next;
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cbuf[cidx] = _bt_getbuf(rel, cblkno[cidx], BT_READ);
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cpage[cidx] = BufferGetPage(cbuf[cidx]);
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copaque[cidx] = (BTPageOpaque) PageGetSpecialPointer(cpage[cidx]);
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coff[cidx] = _bt_getoff(page, cblkno[cidx]);
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/* sanity check */
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if (coff[cidx] != InvalidOffsetNumber)
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{
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for (i = cidx - 1; i >= 0; i--)
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{
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if (coff[i] == InvalidOffsetNumber)
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continue;
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if (coff[cidx] != coff[i] + 1)
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elog(ERROR, "bt_fixlevel: invalid item order(1) (need to recreate index)");
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break;
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}
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}
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if (P_RIGHTMOST(copaque[cidx]))
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break;
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}
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/*
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* Read parent page and insert missed pointers.
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*/
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if (coff[1] == InvalidOffsetNumber ||
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(cidx == 2 && coff[2] == InvalidOffsetNumber))
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{
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Buffer newbuf;
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Page newpage;
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BTPageOpaque newopaque;
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BTItem ritem;
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Size itemsz;
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OffsetNumber newitemoff;
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BlockNumber parblk[3];
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BTStackData stack;
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stack.bts_parent = NULL;
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stack.bts_blkno = pblkno;
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stack.bts_offset = InvalidOffsetNumber;
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ItemPointerSet(&(stack.bts_btitem.bti_itup.t_tid),
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cblkno[0], P_HIKEY);
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buf = _bt_getstackbuf(rel, &stack);
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if (buf == InvalidBuffer)
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elog(ERROR, "bt_fixlevel: pointer disappeared (need to recreate index)");
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page = BufferGetPage(buf);
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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coff[0] = stack.bts_offset;
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pblkno = BufferGetBlockNumber(buf);
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parblk[0] = pblkno;
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if (cblkno[0] == limit)
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blkno = pblkno; /* where we have seen pointer to limit */
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/* Check/insert missed pointers */
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for (i = 1; i <= cidx; i++)
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{
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coff[i] = _bt_getoff(page, cblkno[i]);
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/* sanity check */
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parblk[i] = BufferGetBlockNumber(buf);
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if (coff[i] != InvalidOffsetNumber)
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{
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if (parblk[i] == parblk[i - 1] &&
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coff[i] != coff[i - 1] + 1)
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elog(ERROR, "bt_fixlevel: invalid item order(2) (need to recreate index)");
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if (cblkno[i] == limit)
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blkno = parblk[i];
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continue;
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}
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/* Have to check next page ? */
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if ((! P_RIGHTMOST(opaque)) &&
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coff[i - 1] == PageGetMaxOffsetNumber(page)) /* yes */
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{
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newbuf = _bt_getbuf(rel, opaque->btpo_next, BT_WRITE);
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newpage = BufferGetPage(newbuf);
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newopaque = (BTPageOpaque) PageGetSpecialPointer(newpage);
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coff[i] = _bt_getoff(newpage, cblkno[i]);
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if (coff[i] != InvalidOffsetNumber) /* found ! */
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{
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if (coff[i] != P_FIRSTDATAKEY(newopaque))
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elog(ERROR, "bt_fixlevel: invalid item order(3) (need to recreate index)");
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_bt_relbuf(rel, buf, BT_WRITE);
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buf = newbuf;
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page = newpage;
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opaque = newopaque;
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pblkno = BufferGetBlockNumber(buf);
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parblk[i] = pblkno;
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if (cblkno[i] == limit)
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blkno = pblkno;
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continue;
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}
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/* unfound - need to insert on current page */
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_bt_relbuf(rel, newbuf, BT_WRITE);
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}
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/* insert pointer */
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ritem = (BTItem) PageGetItem(cpage[i - 1],
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PageGetItemId(cpage[i - 1], P_HIKEY));
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btitem = _bt_formitem(&(ritem->bti_itup));
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ItemPointerSet(&(btitem->bti_itup.t_tid), cblkno[i], P_HIKEY);
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itemsz = IndexTupleDSize(btitem->bti_itup)
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+ (sizeof(BTItemData) - sizeof(IndexTupleData));
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itemsz = MAXALIGN(itemsz);
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newitemoff = coff[i - 1] + 1;
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if (PageGetFreeSpace(page) < itemsz)
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{
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OffsetNumber firstright;
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OffsetNumber itup_off;
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BlockNumber itup_blkno;
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bool newitemonleft;
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firstright = _bt_findsplitloc(rel, page,
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newitemoff, itemsz, &newitemonleft);
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newbuf = _bt_split(rel, buf, firstright,
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newitemoff, itemsz, btitem, newitemonleft,
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&itup_off, &itup_blkno);
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/* what buffer we need in ? */
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if (newitemonleft)
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_bt_relbuf(rel, newbuf, BT_WRITE);
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else
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{
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_bt_relbuf(rel, buf, BT_WRITE);
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buf = newbuf;
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page = BufferGetPage(buf);
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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}
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pblkno = BufferGetBlockNumber(buf);
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coff[i] = itup_off;
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}
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else
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{
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_bt_insertuple(rel, buf, itemsz, btitem, newitemoff);
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coff[i] = newitemoff;
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}
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pfree(btitem);
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parblk[i] = pblkno;
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if (cblkno[i] == limit)
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blkno = pblkno;
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}
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/* copy page with pointer to cblkno[cidx] to temp storage */
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memmove(tbuf, page, PageGetPageSize(page));
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_bt_relbuf(rel, buf, BT_WRITE);
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page = (Page)tbuf;
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opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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if (limit == InvalidBlockNumber)
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blkno = pblkno; /* last visited page */
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}
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/* Continue if current check/fix level page is rightmost */
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if (P_RIGHTMOST(opaque))
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goodbye = false;
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/* Pointers to child pages are Ok - right end of child level ? */
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_bt_relbuf(rel, cbuf[0], BT_READ);
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_bt_relbuf(rel, cbuf[1], BT_READ);
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if (cidx == 1 ||
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(cidx == 2 && (P_RIGHTMOST(copaque[2]) || goodbye)))
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{
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if (cidx == 2)
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_bt_relbuf(rel, cbuf[2], BT_READ);
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return(blkno);
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}
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if (cblkno[0] == limit || cblkno[1] == limit)
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goodbye = true;
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cblkno[0] = cblkno[2];
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cbuf[0] = cbuf[2];
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cpage[0] = cpage[2];
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copaque[0] = copaque[2];
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coff[0] = coff[2];
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}
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}
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static OffsetNumber
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_bt_getoff(Page page, BlockNumber blkno)
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{
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BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page);
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OffsetNumber maxoff = PageGetMaxOffsetNumber(page);
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OffsetNumber offnum = P_FIRSTDATAKEY(opaque);
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BlockNumber curblkno;
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ItemId itemid;
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BTItem item;
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for ( ; offnum <= maxoff; offnum++)
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{
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itemid = PageGetItemId(page, offnum);
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item = (BTItem) PageGetItem(page, itemid);
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curblkno = ItemPointerGetBlockNumber(&(item->bti_itup.t_tid));
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if (curblkno == blkno)
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return(offnum);
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}
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return(InvalidOffsetNumber);
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}
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/*
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Reference in New Issue
Block a user