diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c
index 21c05be3c1cf4ad2ab22913fbb4e9abf8e748f78..a7a3d7a12d6b441fe9596c6870cf34cbf73c7b3d 100644
--- a/src/backend/access/nbtree/nbtutils.c
+++ b/src/backend/access/nbtree/nbtutils.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/access/nbtree/nbtutils.c,v 1.96 2010/01/02 16:57:35 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/access/nbtree/nbtutils.c,v 1.97 2010/01/03 05:39:08 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -32,7 +32,7 @@
static bool _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op,
ScanKey leftarg, ScanKey rightarg,
bool *result);
-static void _bt_mark_scankey_with_indoption(ScanKey skey, int16 *indoption);
+static bool _bt_fix_scankey_strategy(ScanKey skey, int16 *indoption);
static void _bt_mark_scankey_required(ScanKey skey);
static bool _bt_check_rowcompare(ScanKey skey,
IndexTuple tuple, TupleDesc tupdesc,
@@ -265,49 +265,9 @@ _bt_preprocess_keys(IndexScanDesc scan)
/* We can short-circuit most of the work if there's just one key */
if (numberOfKeys == 1)
{
- /*
- * We treat all btree operators as strict (even if they're not so
- * marked in pg_proc). This means that it is impossible for an
- * operator condition with a NULL comparison constant to succeed, and
- * we can reject it right away.
- *
- * However, we now also support "x IS NULL" clauses as search
- * conditions, so in that case keep going. The planner has not filled
- * in any particular strategy in this case, so set it to
- * BTEqualStrategyNumber --- we can treat IS NULL as an equality
- * operator for purposes of search strategy.
- *
- * Likewise, "x IS NOT NULL" is supported. We treat that as either
- * "less than NULL" in a NULLS LAST index, or "greater than NULL"
- * in a NULLS FIRST index. However, we have to flip those around in
- * a DESC index, to allow for the re-flipping that occurs elsewhere.
- */
- if (cur->sk_flags & SK_ISNULL)
- {
- if (cur->sk_flags & SK_SEARCHNULL)
- {
- cur->sk_strategy = BTEqualStrategyNumber;
- cur->sk_subtype = InvalidOid;
- }
- else if (cur->sk_flags & SK_SEARCHNOTNULL)
- {
- switch (indoption[cur->sk_attno - 1] &
- (INDOPTION_DESC | INDOPTION_NULLS_FIRST))
- {
- case 0: /* ASC / NULLS LAST */
- case INDOPTION_DESC | INDOPTION_NULLS_FIRST:
- cur->sk_strategy = BTLessStrategyNumber;
- break;
- default:
- cur->sk_strategy = BTGreaterStrategyNumber;
- break;
- }
- cur->sk_subtype = InvalidOid;
- }
- else
- so->qual_ok = false;
- }
- _bt_mark_scankey_with_indoption(cur, indoption);
+ /* Apply indoption to scankey (might change sk_strategy!) */
+ if (!_bt_fix_scankey_strategy(cur, indoption))
+ so->qual_ok = false;
memcpy(outkeys, cur, sizeof(ScanKeyData));
so->numberOfKeys = 1;
/* We can mark the qual as required if it's for first index col */
@@ -340,35 +300,12 @@ _bt_preprocess_keys(IndexScanDesc scan)
{
if (i < numberOfKeys)
{
- /* See comments above about NULLs and IS NULL/NOT NULL handling */
- /* Note: we assume SK_ISNULL is never set in a row header key */
- if (cur->sk_flags & SK_ISNULL)
+ /* Apply indoption to scankey (might change sk_strategy!) */
+ if (!_bt_fix_scankey_strategy(cur, indoption))
{
- if (cur->sk_flags & SK_SEARCHNULL)
- {
- cur->sk_strategy = BTEqualStrategyNumber;
- cur->sk_subtype = InvalidOid;
- }
- else if (cur->sk_flags & SK_SEARCHNOTNULL)
- {
- switch (indoption[cur->sk_attno - 1] &
- (INDOPTION_DESC | INDOPTION_NULLS_FIRST))
- {
- case 0: /* ASC / NULLS LAST */
- case INDOPTION_DESC | INDOPTION_NULLS_FIRST:
- cur->sk_strategy = BTLessStrategyNumber;
- break;
- default:
- cur->sk_strategy = BTGreaterStrategyNumber;
- break;
- }
- cur->sk_subtype = InvalidOid;
- }
- else
- {
- so->qual_ok = false;
- return;
- }
+ /* NULL can't be matched, so give up */
+ so->qual_ok = false;
+ return;
}
}
@@ -480,9 +417,6 @@ _bt_preprocess_keys(IndexScanDesc scan)
memset(xform, 0, sizeof(xform));
}
- /* apply indoption to scankey (might change sk_strategy!) */
- _bt_mark_scankey_with_indoption(cur, indoption);
-
/* check strategy this key's operator corresponds to */
j = cur->sk_strategy - 1;
@@ -678,7 +612,7 @@ _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op,
* indexscan initiated by syscache lookup will use cross-data-type
* operators.)
*
- * If the sk_strategy was flipped by _bt_mark_scankey_with_indoption, we
+ * If the sk_strategy was flipped by _bt_fix_scankey_strategy, we
* have to un-flip it to get the correct opfamily member.
*/
strat = op->sk_strategy;
@@ -708,12 +642,20 @@ _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op,
}
/*
- * Mark a scankey with info from the index's indoption array.
+ * Adjust a scankey's strategy and flags setting as needed for indoptions.
*
* We copy the appropriate indoption value into the scankey sk_flags
* (shifting to avoid clobbering system-defined flag bits). Also, if
* the DESC option is set, commute (flip) the operator strategy number.
*
+ * A secondary purpose is to check for IS NULL/NOT NULL scankeys and set up
+ * the strategy field correctly for them.
+ *
+ * Lastly, for ordinary scankeys (not IS NULL/NOT NULL), we check for a
+ * NULL comparison value. Since all btree operators are assumed strict,
+ * a NULL means that the qual cannot be satisfied. We return TRUE if the
+ * comparison value isn't NULL, or FALSE if the scan should be abandoned.
+ *
* This function is applied to the *input* scankey structure; therefore
* on a rescan we will be looking at already-processed scankeys. Hence
* we have to be careful not to re-commute the strategy if we already did it.
@@ -721,16 +663,67 @@ _bt_compare_scankey_args(IndexScanDesc scan, ScanKey op,
* there shouldn't be any problem, since the index's indoptions are certainly
* not going to change while the scankey survives.
*/
-static void
-_bt_mark_scankey_with_indoption(ScanKey skey, int16 *indoption)
+static bool
+_bt_fix_scankey_strategy(ScanKey skey, int16 *indoption)
{
int addflags;
addflags = indoption[skey->sk_attno - 1] << SK_BT_INDOPTION_SHIFT;
+
+ /*
+ * We treat all btree operators as strict (even if they're not so marked
+ * in pg_proc). This means that it is impossible for an operator condition
+ * with a NULL comparison constant to succeed, and we can reject it right
+ * away.
+ *
+ * However, we now also support "x IS NULL" clauses as search conditions,
+ * so in that case keep going. The planner has not filled in any
+ * particular strategy in this case, so set it to BTEqualStrategyNumber
+ * --- we can treat IS NULL as an equality operator for purposes of search
+ * strategy.
+ *
+ * Likewise, "x IS NOT NULL" is supported. We treat that as either "less
+ * than NULL" in a NULLS LAST index, or "greater than NULL" in a NULLS
+ * FIRST index.
+ */
+ if (skey->sk_flags & SK_ISNULL)
+ {
+ /* SK_ISNULL shouldn't be set in a row header scankey */
+ Assert(!(skey->sk_flags & SK_ROW_HEADER));
+
+ /* Set indoption flags in scankey (might be done already) */
+ skey->sk_flags |= addflags;
+
+ /* Set correct strategy for IS NULL or NOT NULL search */
+ if (skey->sk_flags & SK_SEARCHNULL)
+ {
+ skey->sk_strategy = BTEqualStrategyNumber;
+ skey->sk_subtype = InvalidOid;
+ }
+ else if (skey->sk_flags & SK_SEARCHNOTNULL)
+ {
+ if (skey->sk_flags & SK_BT_NULLS_FIRST)
+ skey->sk_strategy = BTGreaterStrategyNumber;
+ else
+ skey->sk_strategy = BTLessStrategyNumber;
+ skey->sk_subtype = InvalidOid;
+ }
+ else
+ {
+ /* regular qual, so it cannot be satisfied */
+ return false;
+ }
+
+ /* Needn't do the rest */
+ return true;
+ }
+
+ /* Adjust strategy for DESC, if we didn't already */
if ((addflags & SK_BT_DESC) && !(skey->sk_flags & SK_BT_DESC))
skey->sk_strategy = BTCommuteStrategyNumber(skey->sk_strategy);
skey->sk_flags |= addflags;
+ /* If it's a row header, fix row member flags and strategies similarly */
if (skey->sk_flags & SK_ROW_HEADER)
{
ScanKey subkey = (ScanKey) DatumGetPointer(skey->sk_argument);
@@ -747,6 +740,8 @@ _bt_mark_scankey_with_indoption(ScanKey skey, int16 *indoption)
subkey++;
}
}
+
+ return true;
}
/*