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Diffstat (limited to 'src/backend/access/nbtree/nbtsearch.c')
-rw-r--r--src/backend/access/nbtree/nbtsearch.c131
1 files changed, 98 insertions, 33 deletions
diff --git a/src/backend/access/nbtree/nbtsearch.c b/src/backend/access/nbtree/nbtsearch.c
index 2e802ee8527..99fb38f18ce 100644
--- a/src/backend/access/nbtree/nbtsearch.c
+++ b/src/backend/access/nbtree/nbtsearch.c
@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtsearch.c,v 1.15 1997/03/18 18:38:41 scrappy Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtsearch.c,v 1.16 1997/03/24 08:48:12 vadim Exp $
*
*-------------------------------------------------------------------------
*/
@@ -19,6 +19,7 @@
#include <storage/bufpage.h>
#include <storage/bufmgr.h>
#include <access/nbtree.h>
+#include <catalog/pg_proc.h>
#ifndef HAVE_MEMMOVE
# include <regex/utils.h>
@@ -238,7 +239,20 @@ _bt_skeycmp(Relation rel,
Datum keyDatum;
bool compare;
bool isNull;
+ bool useEqual = false;
+ bool keyNull;
+ if ( strat == BTLessEqualStrategyNumber )
+ {
+ useEqual = true;
+ strat = BTLessStrategyNumber;
+ }
+ else if ( strat == BTGreaterEqualStrategyNumber )
+ {
+ useEqual = true;
+ strat = BTGreaterStrategyNumber;
+ }
+
item = (BTItem) PageGetItem(page, itemid);
indexTuple = &(item->bti_itup);
@@ -248,27 +262,60 @@ _bt_skeycmp(Relation rel,
for (i=1; i <= keysz; i++) {
entry = &scankey[i-1];
+ Assert ( entry->sk_attno == i );
attrDatum = index_getattr(indexTuple,
entry->sk_attno,
tupDes,
&isNull);
keyDatum = entry->sk_argument;
-
- /*
- * This may happen in a nested loop if an attribute used
- * as scan key is null. DZ 29-10-1996
- */
- if ((entry->sk_flags & SK_ISNULL) || (isNull)) {
- if ((entry->sk_flags & SK_ISNULL) && (isNull)) {
- return (true);
- } else {
- return (false);
- }
+
+ /* see comments about NULLs handling in btbuild */
+ if ( entry->sk_flags & SK_ISNULL ) /* key is NULL */
+ {
+ Assert ( entry->sk_procedure == NullValueRegProcedure );
+ keyNull = true;
+ if ( isNull )
+ compare = ( strat == BTEqualStrategyNumber ) ? true : false;
+ else
+ compare = ( strat == BTGreaterStrategyNumber ) ? true : false;
+ }
+ else if ( isNull ) /* key is NOT_NULL and item is NULL */
+ {
+ keyNull = false;
+ compare = ( strat == BTLessStrategyNumber ) ? true : false;
+ }
+ else
+ {
+ keyNull = false;
+ compare = _bt_invokestrat(rel, i, strat, keyDatum, attrDatum);
}
- compare = _bt_invokestrat(rel, i, strat, keyDatum, attrDatum);
- if (!compare)
+ if ( compare ) /* true for one of ">, <, =" */
+ {
+ if ( strat != BTEqualStrategyNumber )
+ return (true);
+ }
+ else /* false for one of ">, <, =" */
+ {
+ if ( strat == BTEqualStrategyNumber )
+ return (false);
+ /*
+ * if original strat was "<=, >=" OR
+ * "<, >" but some attribute(s) left
+ * - need to test for Equality
+ */
+ if ( useEqual || i < keysz )
+ {
+ if ( keyNull || isNull )
+ compare = ( keyNull && isNull ) ? true : false;
+ else
+ compare = _bt_invokestrat(rel, i, BTEqualStrategyNumber,
+ keyDatum, attrDatum);
+ if ( compare ) /* key' and item' attributes are equal */
+ continue; /* - try to compare next attributes */
+ }
return (false);
+ }
}
return (true);
@@ -520,20 +567,24 @@ _bt_compare(Relation rel,
attno = entry->sk_attno;
datum = index_getattr(itup, attno, itupdesc, &null);
- /*
- * This may happen in a nested loop if an attribute used
- * as scan key is null. DZ 29-10-1996
- */
- if ((entry->sk_flags & SK_ISNULL) || (null)) {
- if ((entry->sk_flags & SK_ISNULL) && (null)) {
- return (0);
- } else {
- return (null ? +1 : -1);
- }
+ /* see comments about NULLs handling in btbuild */
+ if ( entry->sk_flags & SK_ISNULL ) /* key is NULL */
+ {
+ Assert ( entry->sk_procedure == NullValueRegProcedure );
+ if ( null )
+ tmpres = (long) 0; /* NULL "=" NULL */
+ else
+ tmpres = (long) 1; /* NULL ">" NOT_NULL */
+ }
+ else if ( null ) /* key is NOT_NULL and item is NULL */
+ {
+ tmpres = (long) -1; /* NOT_NULL "<" NULL */
+ }
+ else
+ {
+ tmpres = (long) FMGR_PTR2(entry->sk_func, entry->sk_procedure,
+ entry->sk_argument, datum);
}
-
- tmpres = (long) FMGR_PTR2(entry->sk_func, entry->sk_procedure,
- entry->sk_argument, datum);
result = tmpres;
/* if the keys are unequal, return the difference */
@@ -566,6 +617,7 @@ _bt_next(IndexScanDesc scan, ScanDirection dir)
BTItem btitem;
IndexTuple itup;
BTScanOpaque so;
+ Size keysok;
rel = scan->relation;
so = (BTScanOpaque) scan->opaque;
@@ -596,8 +648,9 @@ _bt_next(IndexScanDesc scan, ScanDirection dir)
btitem = (BTItem) PageGetItem(page, PageGetItemId(page, offnum));
itup = &btitem->bti_itup;
- if (_bt_checkqual(scan, itup))
+ if ( _bt_checkkeys (scan, itup, &keysok) )
{
+ Assert (keysok == so->numberOfKeys);
res = FormRetrieveIndexResult(current, &(itup->t_tid));
/* remember which buffer we have pinned and locked */
@@ -605,7 +658,7 @@ _bt_next(IndexScanDesc scan, ScanDirection dir)
return (res);
}
- } while ( _bt_checkforkeys (scan, itup, so->numberOfFirstKeys) );
+ } while ( keysok >= so->numberOfFirstKeys );
ItemPointerSetInvalid(current);
so->btso_curbuf = InvalidBuffer;
@@ -644,6 +697,7 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
int result;
BTScanOpaque so;
ScanKeyData skdata;
+ Size keysok;
so = (BTScanOpaque) scan->opaque;
if ( so->qual_ok == 0 ) /* may be set by _bt_orderkeys */
@@ -663,6 +717,12 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
* ordered to take advantage of index ordering) to position ourselves
* at the right place in the scan.
*/
+ /* _bt_orderkeys disallows it, but it's place to add some code latter */
+ if ( so->keyData[0].sk_flags & SK_ISNULL )
+ {
+ elog (WARN, "_bt_first: btree doesn't support is(not)null, yet");
+ return ((RetrieveIndexResult) NULL);
+ }
proc = index_getprocid(rel, 1, BTORDER_PROC);
ScanKeyEntryInitialize(&skdata, so->keyData[0].sk_flags, 1, proc,
so->keyData[0].sk_argument);
@@ -706,6 +766,9 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
*/
result = _bt_compare(rel, itupdesc, page, 1, &skdata, offnum);
+
+ /* it's yet other place to add some code latter for is(not)null */
+
strat = _bt_getstrat(rel, 1, so->keyData[0].sk_procedure);
switch (strat) {
@@ -798,14 +861,14 @@ _bt_first(IndexScanDesc scan, ScanDirection dir)
btitem = (BTItem) PageGetItem(page, PageGetItemId(page, offnum));
itup = &btitem->bti_itup;
- if ( _bt_checkqual(scan, itup) )
+ if ( _bt_checkkeys (scan, itup, &keysok) )
{
res = FormRetrieveIndexResult(current, &(itup->t_tid));
/* remember which buffer we have pinned */
so->btso_curbuf = buf;
}
- else if ( _bt_checkforkeys (scan, itup, so->numberOfFirstKeys) )
+ else if ( keysok >= so->numberOfFirstKeys )
{
so->btso_curbuf = buf;
return (_bt_next (scan, dir));
@@ -1081,6 +1144,7 @@ _bt_endpoint(IndexScanDesc scan, ScanDirection dir)
IndexTuple itup;
BTScanOpaque so;
RetrieveIndexResult res;
+ Size keysok;
rel = scan->relation;
current = &(scan->currentItemData);
@@ -1223,13 +1287,14 @@ _bt_endpoint(IndexScanDesc scan, ScanDirection dir)
itup = &(btitem->bti_itup);
/* see if we picked a winner */
- if (_bt_checkqual(scan, itup)) {
+ if ( _bt_checkkeys (scan, itup, &keysok) )
+ {
res = FormRetrieveIndexResult(current, &(itup->t_tid));
/* remember which buffer we have pinned */
so->btso_curbuf = buf;
}
- else if ( _bt_checkforkeys (scan, itup, so->numberOfFirstKeys) )
+ else if ( keysok >= so->numberOfFirstKeys )
{
so->btso_curbuf = buf;
return (_bt_next (scan, dir));
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-27 16:17:50 +0000