Remove a no-longer-needed kluge for degenerate aggregate cases,

and update some comments.

diff --git a/src/backend/executor/execQual.c b/src/backend/executor/execQual.c
index 81a1975a4a23755c3d016f07cb3bf907692914c7..2d972f5922990695ca8144035bb1ed250d5ad932 100644 (file)
--- a/src/backend/executor/execQual.c
+++ b/src/backend/executor/execQual.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/executor/execQual.c,v 1.62 1999/09/26 21:21:09 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/executor/execQual.c,v 1.63 1999/10/08 03:49:55 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -209,6 +209,9 @@ ExecEvalArrayRef(ArrayRef *arrayRef,
 static Datum
 ExecEvalAggref(Aggref *aggref, ExprContext *econtext, bool *isNull)
 {
+       if (econtext->ecxt_aggvalues == NULL) /* safety check */
+               elog(ERROR, "ExecEvalAggref: no aggregates in this expression context");
+
        *isNull = econtext->ecxt_aggnulls[aggref->aggno];
        return econtext->ecxt_aggvalues[aggref->aggno];
 }

diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
index c37f4c4f42f9c49d520f04525fbe9e8cb76c0b1b..16b28060a68e67780998e25f15a07e69815dd204 100644 (file)
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -11,7 +11,7 @@
  *       SQL aggregates. (Do not expect POSTQUEL semantics.)    -- ay 2/95
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.56 1999/09/28 02:03:19 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.57 1999/10/08 03:49:55 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -136,12 +136,11 @@ copyDatum(Datum val, int typLen, bool typByVal)
  *       sfunc1 is never applied when the current tuple's aggregated_value
  *       is NULL.  sfunc2 is applied for each tuple if the aggref is marked
  *       'usenulls', otherwise it is only applied when aggregated_value is
- *       not NULL.  (usenulls is normally set only for the case of COUNT(*),
- *       since according to the SQL92 standard that is the only aggregate
- *       that considers nulls in its input.  SQL92 requires COUNT(*) and
- *       COUNT(field) to behave differently --- the latter doesn't count nulls
- *       --- so we can't make this flag a column of pg_aggregate but must
- *       set it according to usage.  Ugh.)
+ *       not NULL.  (usenulls was formerly used for COUNT(*), but is no longer
+ *       needed for that purpose; as of 10/1999 the support for usenulls is
+ *       dead code.  I have not removed it because it seems like a potentially
+ *       useful feature for user-defined aggregates.  We'd just need to add a
+ *       flag column to pg_aggregate and a parameter to CREATE AGGREGATE...)
  *
  *       If the outer subplan is a Group node, ExecAgg returns as many tuples
  *       as there are groups.
@@ -534,27 +533,14 @@ ExecInitAgg(Agg *node, EState *estate, Plan *parent)
        outerPlan = outerPlan(node);
        ExecInitNode(outerPlan, estate, (Plan *) node);
 
-       /*
-        * Result runs in its own context, but make it use our aggregates fix
-        * for 'select sum(2+2)'
-        */
-       if (IsA(outerPlan, Result))
-       {
-               ((Result *) outerPlan)->resstate->cstate.cs_ProjInfo->pi_exprContext->ecxt_aggvalues =
-                       econtext->ecxt_aggvalues;
-               ((Result *) outerPlan)->resstate->cstate.cs_ProjInfo->pi_exprContext->ecxt_aggnulls =
-                       econtext->ecxt_aggnulls;
-       }
-
        /* ----------------
-        *      initialize tuple type.
+        *      initialize source tuple type.
         * ----------------
         */
        ExecAssignScanTypeFromOuterPlan((Plan *) node, &aggstate->csstate);
 
        /*
-        * Initialize tuple type for both result and scan. This node does no
-        * projection
+        * Initialize result tuple type and projection info.
         */
        ExecAssignResultTypeFromTL((Plan *) node, &aggstate->csstate.cstate);
        ExecAssignProjectionInfo((Plan *) node, &aggstate->csstate.cstate);