diff options
Diffstat (limited to 'src/backend/access/nbtree/nbtutils.c')
| -rw-r--r-- | src/backend/access/nbtree/nbtutils.c | 86 |
1 files changed, 42 insertions, 44 deletions
diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c index 9a5f8d7ac90..269213d21f7 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 1.63 2005/06/13 23:14:48 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/access/nbtree/nbtutils.c,v 1.64 2005/10/15 02:49:09 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -48,8 +48,8 @@ _bt_mkscankey(Relation rel, IndexTuple itup) bool null; /* - * We can use the cached (default) support procs since no - * cross-type comparison can be needed. + * We can use the cached (default) support procs since no cross-type + * comparison can be needed. */ procinfo = index_getprocinfo(rel, i + 1, BTORDER_PROC); arg = index_getattr(itup, i + 1, itupdesc, &null); @@ -93,8 +93,8 @@ _bt_mkscankey_nodata(Relation rel) FmgrInfo *procinfo; /* - * We can use the cached (default) support procs since no - * cross-type comparison can be needed. + * We can use the cached (default) support procs since no cross-type + * comparison can be needed. */ procinfo = index_getprocinfo(rel, i + 1, BTORDER_PROC); ScanKeyEntryInitializeWithInfo(&skey[i], @@ -257,9 +257,9 @@ _bt_preprocess_keys(IndexScanDesc scan) if (numberOfKeys == 1) { /* - * We don't use indices for 'A is null' and 'A is not null' - * currently and 'A < = > <> NULL' will always fail - so qual is - * not OK if comparison value is NULL. - vadim 03/21/97 + * We don't use indices for 'A is null' and 'A is not null' currently + * and 'A < = > <> NULL' will always fail - so qual is not OK if + * comparison value is NULL. - vadim 03/21/97 */ if (cur->sk_flags & SK_ISNULL) so->qual_ok = false; @@ -286,20 +286,20 @@ _bt_preprocess_keys(IndexScanDesc scan) /* * Initialize for processing of keys for attr 1. * - * xform[i] points to the currently best scan key of strategy type i+1, - * if any is found with a default operator subtype; it is NULL if we - * haven't yet found such a key for this attr. Scan keys of - * nondefault subtypes are transferred to the output with no - * processing except for noting if they are of "=" type. + * xform[i] points to the currently best scan key of strategy type i+1, if + * any is found with a default operator subtype; it is NULL if we haven't + * yet found such a key for this attr. Scan keys of nondefault subtypes + * are transferred to the output with no processing except for noting if + * they are of "=" type. */ attno = 1; memset(xform, 0, sizeof(xform)); hasOtherTypeEqual = false; /* - * Loop iterates from 0 to numberOfKeys inclusive; we use the last - * pass to handle after-last-key processing. Actual exit from the - * loop is at the "break" statement below. + * Loop iterates from 0 to numberOfKeys inclusive; we use the last pass to + * handle after-last-key processing. Actual exit from the loop is at the + * "break" statement below. */ for (i = 0;; cur++, i++) { @@ -319,8 +319,8 @@ _bt_preprocess_keys(IndexScanDesc scan) } /* - * If we are at the end of the keys for a particular attr, finish - * up processing and emit the cleaned-up keys. + * If we are at the end of the keys for a particular attr, finish up + * processing and emit the cleaned-up keys. */ if (i == numberOfKeys || cur->sk_attno != attno) { @@ -331,9 +331,9 @@ _bt_preprocess_keys(IndexScanDesc scan) elog(ERROR, "btree index keys must be ordered by attribute"); /* - * If = has been specified, no other key will be used. In case - * of key > 2 && key == 1 and so on we have to set qual_ok to - * false before discarding the other keys. + * If = has been specified, no other key will be used. In case of + * key > 2 && key == 1 and so on we have to set qual_ok to false + * before discarding the other keys. */ if (xform[BTEqualStrategyNumber - 1]) { @@ -411,8 +411,8 @@ _bt_preprocess_keys(IndexScanDesc scan) } /* - * If all attrs before this one had "=", include these keys - * into the required-keys count. + * If all attrs before this one had "=", include these keys into + * the required-keys count. */ if (priorNumberOfEqualCols == attno - 1) so->numberOfRequiredKeys = new_numberOfKeys; @@ -526,11 +526,11 @@ _bt_checkkeys(IndexScanDesc scan, IndexTuple tuple, if (isNull) { /* - * Since NULLs are sorted after non-NULLs, we know we have - * reached the upper limit of the range of values for this - * index attr. On a forward scan, we can stop if this qual is - * one of the "must match" subset. On a backward scan, - * however, we should keep going. + * Since NULLs are sorted after non-NULLs, we know we have reached + * the upper limit of the range of values for this index attr. On + * a forward scan, we can stop if this qual is one of the "must + * match" subset. On a backward scan, however, we should keep + * going. */ if (ikey < so->numberOfRequiredKeys && ScanDirectionIsForward(dir)) @@ -547,24 +547,22 @@ _bt_checkkeys(IndexScanDesc scan, IndexTuple tuple, if (!DatumGetBool(test)) { /* - * Tuple fails this qual. If it's a required qual, then we - * may be able to conclude no further tuples will pass, - * either. We have to look at the scan direction and the qual - * type. + * Tuple fails this qual. If it's a required qual, then we may be + * able to conclude no further tuples will pass, either. We have + * to look at the scan direction and the qual type. * - * Note: the only case in which we would keep going after failing - * a required qual is if there are partially-redundant quals - * that _bt_preprocess_keys() was unable to eliminate. For - * example, given "x > 4 AND x > 10" where both are cross-type - * comparisons and so not removable, we might start the scan - * at the x = 4 boundary point. The "x > 10" condition will - * fail until we pass x = 10, but we must not stop the scan on - * its account. + * Note: the only case in which we would keep going after failing a + * required qual is if there are partially-redundant quals that + * _bt_preprocess_keys() was unable to eliminate. For example, + * given "x > 4 AND x > 10" where both are cross-type comparisons + * and so not removable, we might start the scan at the x = 4 + * boundary point. The "x > 10" condition will fail until we pass + * x = 10, but we must not stop the scan on its account. * - * Note: because we stop the scan as soon as any required - * equality qual fails, it is critical that equality quals be - * used for the initial positioning in _bt_first() when they - * are available. See comments in _bt_first(). + * Note: because we stop the scan as soon as any required equality + * qual fails, it is critical that equality quals be used for the + * initial positioning in _bt_first() when they are available. See + * comments in _bt_first(). */ if (ikey < so->numberOfRequiredKeys) { |