Calculation of keys_are_unique flag was wrong for cases involving

redundant cross-datatype comparisons.  Per example from Merlin Moncure.

diff --git a/src/backend/access/nbtree/nbtutils.c b/src/backend/access/nbtree/nbtutils.c
index bd640f6f8b5aba72276c58451f925d836c9dedb3..03b9cf080cac6ebb4310467481f8c1e1ac3af5f2 100644 (file)
--- 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 1.60 2004/08/29 05:06:40 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/access/nbtree/nbtutils.c,v 1.61 2004/12/15 19:16:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -224,11 +224,11 @@ _bt_preprocess_keys(IndexScanDesc scan)
        BTScanOpaque so = (BTScanOpaque) scan->opaque;
        int                     numberOfKeys = scan->numberOfKeys;
        int                     new_numberOfKeys;
+       int                     numberOfEqualCols;
        ScanKey         inkeys;
        ScanKey         outkeys;
        ScanKey         cur;
        ScanKey         xform[BTMaxStrategyNumber];
-       bool            allEqualSoFar;
        bool            hasOtherTypeEqual;
        Datum           test;
        int                     i,
@@ -278,7 +278,7 @@ _bt_preprocess_keys(IndexScanDesc scan)
         * Otherwise, do the full set of pushups.
         */
        new_numberOfKeys = 0;
-       allEqualSoFar = true;
+       numberOfEqualCols = 0;
 
        /*
         * Initialize for processing of keys for attr 1.
@@ -321,7 +321,7 @@ _bt_preprocess_keys(IndexScanDesc scan)
                 */
                if (i == numberOfKeys || cur->sk_attno != attno)
                {
-                       bool            priorAllEqualSoFar = allEqualSoFar;
+                       int                     priorNumberOfEqualCols = numberOfEqualCols;
 
                        /* check input keys are correctly ordered */
                        if (i < numberOfKeys && cur->sk_attno != attno + 1)
@@ -355,14 +355,14 @@ _bt_preprocess_keys(IndexScanDesc scan)
                                xform[BTLessEqualStrategyNumber - 1] = NULL;
                                xform[BTGreaterEqualStrategyNumber - 1] = NULL;
                                xform[BTGreaterStrategyNumber - 1] = NULL;
+                               /* track number of attrs for which we have "=" keys */
+                               numberOfEqualCols++;
                        }
                        else
                        {
-                               /*
-                                * If no "=" for this key, we're done with required keys
-                                */
-                               if (!hasOtherTypeEqual)
-                                       allEqualSoFar = false;
+                               /* track number of attrs for which we have "=" keys */
+                               if (hasOtherTypeEqual)
+                                       numberOfEqualCols++;
                        }
 
                        /* keep only one of <, <= */
@@ -411,7 +411,7 @@ _bt_preprocess_keys(IndexScanDesc scan)
                         * If all attrs before this one had "=", include these keys
                         * into the required-keys count.
                         */
-                       if (priorAllEqualSoFar)
+                       if (priorNumberOfEqualCols == attno - 1)
                                so->numberOfRequiredKeys = new_numberOfKeys;
 
                        /*
@@ -468,8 +468,8 @@ _bt_preprocess_keys(IndexScanDesc scan)
         * If unique index and we have equality keys for all columns, set
         * keys_are_unique flag for higher levels.
         */
-       if (allEqualSoFar && relation->rd_index->indisunique &&
-               relation->rd_rel->relnatts == new_numberOfKeys)
+       if (relation->rd_index->indisunique &&
+               relation->rd_rel->relnatts == numberOfEqualCols)
                scan->keys_are_unique = true;
 }