Generate a more specific error message when an operator used

in an index doesn't have a restriction selectivity estimator.

diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fc65ddc3f97c5b34623b606a9c665679c427322a..eb6bf5570335cb62156261dce4315bab496626b3 100644 (file)
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -12,7 +12,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.28 1999/05/25 16:12:20 momjian Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.29 1999/05/31 19:32:47 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -404,7 +404,21 @@ btreesel(Oid operatorObjectId,
    }
    else
    {
-       result = (float64) fmgr(get_oprrest(operatorObjectId),
+       RegProcedure oprrest = get_oprrest(operatorObjectId);
+
+       /*
+        * Operators used for indexes should have selectivity estimators.
+        * (An alternative is to default to 0.5, as the optimizer does in
+        * dealing with operators occurring in WHERE clauses, but if you
+        * are going to the trouble of making index support you probably
+        * don't want to miss the benefits of a good selectivity estimate.)
+        */
+       if (!oprrest)
+           elog(ERROR,
+                "Operator %u must have a restriction selectivity estimator to be used in a btree index",
+                operatorObjectId);
+
+       result = (float64) fmgr(oprrest,
                                (char *) operatorObjectId,
                                (char *) indrelid,
                                (char *) (int) attributeNumber,
@@ -449,7 +463,21 @@ btreenpage(Oid operatorObjectId,
    }
    else
    {
-       temp = (float64) fmgr(get_oprrest(operatorObjectId),
+       RegProcedure oprrest = get_oprrest(operatorObjectId);
+
+       /*
+        * Operators used for indexes should have selectivity estimators.
+        * (An alternative is to default to 0.5, as the optimizer does in
+        * dealing with operators occurring in WHERE clauses, but if you
+        * are going to the trouble of making index support you probably
+        * don't want to miss the benefits of a good selectivity estimate.)
+        */
+       if (!oprrest)
+           elog(ERROR,
+                "Operator %u must have a restriction selectivity estimator to be used in a btree index",
+                operatorObjectId);
+
+       temp = (float64) fmgr(oprrest,
                              (char *) operatorObjectId,
                              (char *) indrelid,
                              (char *) (int) attributeNumber,
@@ -514,7 +542,21 @@ hashsel(Oid operatorObjectId,
    }
    else
    {
-       result = (float64) fmgr(get_oprrest(operatorObjectId),
+       RegProcedure oprrest = get_oprrest(operatorObjectId);
+
+       /*
+        * Operators used for indexes should have selectivity estimators.
+        * (An alternative is to default to 0.5, as the optimizer does in
+        * dealing with operators occurring in WHERE clauses, but if you
+        * are going to the trouble of making index support you probably
+        * don't want to miss the benefits of a good selectivity estimate.)
+        */
+       if (!oprrest)
+           elog(ERROR,
+                "Operator %u must have a restriction selectivity estimator to be used in a hash index",
+                operatorObjectId);
+
+       result = (float64) fmgr(oprrest,
                                (char *) operatorObjectId,
                                (char *) indrelid,
                                (char *) (int) attributeNumber,
@@ -578,7 +620,21 @@ hashnpage(Oid operatorObjectId,
    }
    else
    {
-       temp = (float64) fmgr(get_oprrest(operatorObjectId),
+       RegProcedure oprrest = get_oprrest(operatorObjectId);
+
+       /*
+        * Operators used for indexes should have selectivity estimators.
+        * (An alternative is to default to 0.5, as the optimizer does in
+        * dealing with operators occurring in WHERE clauses, but if you
+        * are going to the trouble of making index support you probably
+        * don't want to miss the benefits of a good selectivity estimate.)
+        */
+       if (!oprrest)
+           elog(ERROR,
+                "Operator %u must have a restriction selectivity estimator to be used in a hash index",
+                operatorObjectId);
+
+       temp = (float64) fmgr(oprrest,
                              (char *) operatorObjectId,
                              (char *) indrelid,
                              (char *) (int) attributeNumber,