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Currently,only the first column of multi-column indices
is used to find start scan position of Indexscan-s. To speed up finding scan start position,I have changed _bt_first() to use as many keys as possible. I'll attach the patch here. Regards. Hiroshi Inoue
This commit is contained in:
Bruce Momjian
parent
62045e67eb
commit
7b2a8e4e56
@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtsearch.c,v 1.53 1999/07/17 20:16:43 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtsearch.c,v 1.54 1999/09/27 18:20:21 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -727,11 +727,15 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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RegProcedure proc;
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int result;
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BTScanOpaque so;
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ScanKeyData skdata;
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Size keysok;
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int i;
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int nKeyIndex = -1;
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bool strategyCheck;
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ScanKey scankeys = 0;
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int keysCount = 0;
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int *nKeyIs = 0;
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int i, j;
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StrategyNumber strat_total;
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rel = scan->relation;
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so = (BTScanOpaque) scan->opaque;
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@ -742,38 +746,57 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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so->numberOfFirstKeys = 0; /* may be changed by _bt_orderkeys */
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so->qual_ok = 1; /* may be changed by _bt_orderkeys */
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scan->scanFromEnd = false;
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strategyCheck = false;
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if (so->numberOfKeys > 0)
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{
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_bt_orderkeys(rel, so);
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if (ScanDirectionIsBackward(dir))
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if (so->qual_ok)
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strategyCheck = true;
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}
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strat_total = BTEqualStrategyNumber;
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if (strategyCheck)
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{
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AttrNumber attno;
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nKeyIs = (int *)palloc(so->numberOfKeys*sizeof(int));
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for (i=0; i < so->numberOfKeys; i++)
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{
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for (i = 0; i < so->numberOfKeys; i++)
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attno = so->keyData[i].sk_attno;
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if (attno == keysCount)
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continue;
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if (attno > keysCount + 1)
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break;
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strat = _bt_getstrat(rel, attno,
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so->keyData[i].sk_procedure);
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if (strat == strat_total ||
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strat == BTEqualStrategyNumber)
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{
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if (so->keyData[i].sk_attno != 1)
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nKeyIs[keysCount++] = i;
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continue;
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}
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if (ScanDirectionIsBackward(dir) &&
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(strat == BTLessStrategyNumber ||
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strat == BTLessEqualStrategyNumber) )
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{
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nKeyIs[keysCount++] = i;
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strat_total = strat;
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if (strat == BTLessStrategyNumber)
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break;
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strat = _bt_getstrat(rel, so->keyData[i].sk_attno,
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so->keyData[i].sk_procedure);
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if (strat == BTLessStrategyNumber ||
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strat == BTLessEqualStrategyNumber ||
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strat == BTEqualStrategyNumber)
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{
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nKeyIndex = i;
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continue;
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}
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if (ScanDirectionIsForward(dir) &&
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(strat == BTGreaterStrategyNumber ||
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strat == BTGreaterEqualStrategyNumber) )
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{
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nKeyIs[keysCount++] = i;
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strat_total = strat;
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if (strat == BTGreaterStrategyNumber)
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break;
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}
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continue;
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}
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}
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else
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{
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strat = _bt_getstrat(rel, 1, so->keyData[0].sk_procedure);
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if (strat == BTLessStrategyNumber ||
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strat == BTLessEqualStrategyNumber)
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;
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else
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nKeyIndex = 0;
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}
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if (nKeyIndex < 0)
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if (!keysCount)
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scan->scanFromEnd = true;
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}
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else
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@ -784,7 +807,11 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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/* if we just need to walk down one edge of the tree, do that */
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if (scan->scanFromEnd)
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{
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if (nKeyIs)
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pfree(nKeyIs);
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return _bt_endpoint(scan, dir);
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}
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itupdesc = RelationGetDescr(rel);
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current = &(scan->currentItemData);
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@ -796,16 +823,24 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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* at the right place in the scan.
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*/
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/* _bt_orderkeys disallows it, but it's place to add some code latter */
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if (so->keyData[0].sk_flags & SK_ISNULL)
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scankeys = (ScanKey)palloc(keysCount*sizeof(ScanKeyData));
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for (i=0; i < keysCount; i++)
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{
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elog(ERROR, "_bt_first: btree doesn't support is(not)null, yet");
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return (RetrieveIndexResult) NULL;
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j = nKeyIs[i];
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if (so->keyData[j].sk_flags & SK_ISNULL)
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{
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pfree(nKeyIs);
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pfree(scankeys);
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elog(ERROR, "_bt_first: btree doesn't support is(not)null, yet");
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return ((RetrieveIndexResult) NULL);
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}
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proc = index_getprocid(rel, i+1, BTORDER_PROC);
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ScanKeyEntryInitialize(scankeys+i, so->keyData[j].sk_flags,
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i+1, proc, so->keyData[j].sk_argument);
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}
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proc = index_getprocid(rel, 1, BTORDER_PROC);
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ScanKeyEntryInitialize(&skdata, so->keyData[nKeyIndex].sk_flags,
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1, proc, so->keyData[nKeyIndex].sk_argument);
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if (nKeyIs) pfree(nKeyIs);
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stack = _bt_search(rel, 1, &skdata, &buf);
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stack = _bt_search(rel, keysCount, scankeys, &buf);
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_bt_freestack(stack);
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blkno = BufferGetBlockNumber(buf);
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@ -823,6 +858,7 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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ItemPointerSetInvalid(current);
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so->btso_curbuf = InvalidBuffer;
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_bt_relbuf(rel, buf, BT_READ);
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pfree(scankeys);
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return (RetrieveIndexResult) NULL;
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}
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maxoff = PageGetMaxOffsetNumber(page);
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@ -835,7 +871,7 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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*/
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while (maxoff == P_HIKEY && !P_RIGHTMOST(pop) &&
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_bt_skeycmp(rel, 1, &skdata, page,
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_bt_skeycmp(rel, keysCount, scankeys, page,
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PageGetItemId(page, P_HIKEY),
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BTGreaterEqualStrategyNumber))
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{
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@ -849,6 +885,7 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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ItemPointerSetInvalid(current);
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so->btso_curbuf = InvalidBuffer;
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_bt_relbuf(rel, buf, BT_READ);
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pfree(scankeys);
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return (RetrieveIndexResult) NULL;
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}
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maxoff = PageGetMaxOffsetNumber(page);
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@ -857,7 +894,7 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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/* find the nearest match to the manufactured scan key on the page */
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offnum = _bt_binsrch(rel, buf, 1, &skdata, BT_DESCENT);
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offnum = _bt_binsrch(rel, buf, keysCount, scankeys, BT_DESCENT);
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if (offnum > maxoff)
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{
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@ -872,12 +909,11 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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* we're looking for minus the value we're looking at in the index.
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*/
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result = _bt_compare(rel, itupdesc, page, 1, &skdata, offnum);
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result = _bt_compare(rel, itupdesc, page, keysCount, scankeys, offnum);
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/* it's yet other place to add some code latter for is(not)null */
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strat = _bt_getstrat(rel, 1, so->keyData[nKeyIndex].sk_procedure);
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strat = strat_total;
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switch (strat)
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{
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case BTLessStrategyNumber:
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@ -890,7 +926,7 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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offnum = ItemPointerGetOffsetNumber(current);
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page = BufferGetPage(buf);
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result = _bt_compare(rel, itupdesc, page, 1, &skdata, offnum);
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result = _bt_compare(rel, itupdesc, page, keysCount, scankeys, offnum);
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} while (result <= 0);
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}
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@ -906,12 +942,11 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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offnum = ItemPointerGetOffsetNumber(current);
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page = BufferGetPage(buf);
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result = _bt_compare(rel, itupdesc, page, 1, &skdata, offnum);
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result = _bt_compare(rel, itupdesc, page, keysCount, scankeys, offnum);
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} while (result >= 0);
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if (result < 0)
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_bt_twostep(scan, &buf, BackwardScanDirection);
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}
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if (result < 0)
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_bt_twostep(scan, &buf, BackwardScanDirection);
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break;
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case BTEqualStrategyNumber:
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@ -920,6 +955,7 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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_bt_relbuf(scan->relation, buf, BT_READ);
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so->btso_curbuf = InvalidBuffer;
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ItemPointerSetInvalid(&(scan->currentItemData));
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pfree(scankeys);
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return (RetrieveIndexResult) NULL;
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}
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else if (ScanDirectionIsBackward(dir))
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@ -931,7 +967,7 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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offnum = ItemPointerGetOffsetNumber(current);
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page = BufferGetPage(buf);
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result = _bt_compare(rel, itupdesc, page, 1, &skdata, offnum);
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result = _bt_compare(rel, itupdesc, page, keysCount, scankeys, offnum);
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} while (result == 0);
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if (result < 0)
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@ -950,6 +986,7 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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_bt_relbuf(scan->relation, buf, BT_READ);
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so->btso_curbuf = InvalidBuffer;
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ItemPointerSetInvalid(&(scan->currentItemData));
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pfree(scankeys);
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return (RetrieveIndexResult) NULL;
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}
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}
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@ -974,7 +1011,7 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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page = BufferGetPage(buf);
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offnum = ItemPointerGetOffsetNumber(current);
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result = _bt_compare(rel, itupdesc, page, 1, &skdata, offnum);
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result = _bt_compare(rel, itupdesc, page, keysCount, scankeys, offnum);
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} while (result < 0);
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if (result > 0)
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@ -993,12 +1030,13 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
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offnum = ItemPointerGetOffsetNumber(current);
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page = BufferGetPage(buf);
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result = _bt_compare(rel, itupdesc, page, 1, &skdata, offnum);
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result = _bt_compare(rel, itupdesc, page, keysCount, scankeys, offnum);
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} while (result >= 0);
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}
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break;
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}
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pfree(scankeys);
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/* okay, current item pointer for the scan is right */
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offnum = ItemPointerGetOffsetNumber(current);
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page = BufferGetPage(buf);
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@ -7,7 +7,7 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtutils.c,v 1.32 1999/07/17 20:16:43 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtutils.c,v 1.33 1999/09/27 18:20:21 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -101,6 +101,7 @@ _bt_orderkeys(Relation relation, BTScanOpaque so)
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uint16 numberOfKeys = so->numberOfKeys;
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uint16 new_numberOfKeys = 0;
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AttrNumber attno = 1;
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bool equalStrategyEnd, underEqualStrategy;
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if (numberOfKeys < 1)
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return;
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@ -136,6 +137,8 @@ _bt_orderkeys(Relation relation, BTScanOpaque so)
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for (j = 0; j <= BTMaxStrategyNumber; j++)
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init[j] = 0;
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equalStrategyEnd = false;
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underEqualStrategy = true;
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/* check each key passed in */
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for (i = 0;;)
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{
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@ -150,6 +153,7 @@ _bt_orderkeys(Relation relation, BTScanOpaque so)
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if (cur->sk_attno != attno + 1 && i < numberOfKeys)
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elog(ERROR, "_bt_orderkeys: key(s) for attribute %d missed", attno + 1);
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underEqualStrategy = (!equalStrategyEnd);
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/*
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* If = has been specified, no other key will be used. In case
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* of key < 2 && key == 1 and so on we have to set qual_ok to
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@ -175,6 +179,8 @@ _bt_orderkeys(Relation relation, BTScanOpaque so)
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init[BTGreaterEqualStrategyNumber - 1] = 0;
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init[BTGreaterStrategyNumber - 1] = 0;
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}
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else
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equalStrategyEnd = true;
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/* only one of <, <= */
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if (init[BTLessStrategyNumber - 1]
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@ -223,7 +229,7 @@ _bt_orderkeys(Relation relation, BTScanOpaque so)
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if (init[j])
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key[new_numberOfKeys++] = xform[j];
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if (attno == 1)
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if (underEqualStrategy)
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so->numberOfFirstKeys = new_numberOfKeys;
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if (i == numberOfKeys)
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