Faster expression evaluation and targetlist projection.

[postgresql] / src / backend / executor / nodeResult.c

diff --git a/src/backend/executor/nodeResult.c b/src/backend/executor/nodeResult.c
index d8c921a16dc3ec2f20789fd14093950a0fd18d9f..a753a53419183cefebf5c3e0ed9fe6a9f8e8ac37 100644 (file)
--- a/src/backend/executor/nodeResult.c
+++ b/src/backend/executor/nodeResult.c
@@ -34,7 +34,7 @@
  *             plan normally and pass back the results.
  *
  *
- * Portions Copyright (c) 1996-2013, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
@@ -67,10 +67,8 @@ TupleTableSlot *
 ExecResult(ResultState *node)
 {
        TupleTableSlot *outerTupleSlot;
-       TupleTableSlot *resultSlot;
        PlanState  *outerPlan;
        ExprContext *econtext;
-       ExprDoneCond isDone;
 
        econtext = node->ps.ps_ExprContext;
 
@@ -79,9 +77,7 @@ ExecResult(ResultState *node)
         */
        if (node->rs_checkqual)
        {
-               bool            qualResult = ExecQual((List *) node->resconstantqual,
-                                                                                 econtext,
-                                                                                 false);
+               bool            qualResult = ExecQual(node->resconstantqual, econtext);
 
                node->rs_checkqual = false;
                if (!qualResult)
@@ -91,24 +87,9 @@ ExecResult(ResultState *node)
                }
        }
 
-       /*
-        * Check to see if we're still projecting out tuples from a previous scan
-        * tuple (because there is a function-returning-set in the projection
-        * expressions).  If so, try to project another one.
-        */
-       if (node->ps.ps_TupFromTlist)
-       {
-               resultSlot = ExecProject(node->ps.ps_ProjInfo, &isDone);
-               if (isDone == ExprMultipleResult)
-                       return resultSlot;
-               /* Done with that source tuple... */
-               node->ps.ps_TupFromTlist = false;
-       }
-
        /*
         * Reset per-tuple memory context to free any expression evaluation
-        * storage allocated in the previous tuple cycle.  Note this can't happen
-        * until we're done projecting out tuples from a scan tuple.
+        * storage allocated in the previous tuple cycle.
         */
        ResetExprContext(econtext);
 
@@ -147,18 +128,8 @@ ExecResult(ResultState *node)
                        node->rs_done = true;
                }
 
-               /*
-                * form the result tuple using ExecProject(), and return it --- unless
-                * the projection produces an empty set, in which case we must loop
-                * back to see if there are more outerPlan tuples.
-                */
-               resultSlot = ExecProject(node->ps.ps_ProjInfo, &isDone);
-
-               if (isDone != ExprEndResult)
-               {
-                       node->ps.ps_TupFromTlist = (isDone == ExprMultipleResult);
-                       return resultSlot;
-               }
+               /* form the result tuple using ExecProject(), and return it */
+               return ExecProject(node->ps.ps_ProjInfo);
        }
 
        return NULL;
@@ -228,8 +199,6 @@ ExecInitResult(Result *node, EState *estate, int eflags)
         */
        ExecAssignExprContext(estate, &resstate->ps);
 
-       resstate->ps.ps_TupFromTlist = false;
-
        /*
         * tuple table initialization
         */
@@ -238,14 +207,10 @@ ExecInitResult(Result *node, EState *estate, int eflags)
        /*
         * initialize child expressions
         */
-       resstate->ps.targetlist = (List *)
-               ExecInitExpr((Expr *) node->plan.targetlist,
-                                        (PlanState *) resstate);
-       resstate->ps.qual = (List *)
-               ExecInitExpr((Expr *) node->plan.qual,
-                                        (PlanState *) resstate);
-       resstate->resconstantqual = ExecInitExpr((Expr *) node->resconstantqual,
-                                                                                        (PlanState *) resstate);
+       resstate->ps.qual =
+               ExecInitQual(node->plan.qual, (PlanState *) resstate);
+       resstate->resconstantqual =
+               ExecInitQual((List *) node->resconstantqual, (PlanState *) resstate);
 
        /*
         * initialize child nodes
@@ -295,7 +260,6 @@ void
 ExecReScanResult(ResultState *node)
 {
        node->rs_done = false;
-       node->ps.ps_TupFromTlist = false;
        node->rs_checkqual = (node->resconstantqual == NULL) ? false : true;
 
        /*