Avoid extra AggCheckCallContext() checks in ordered-set aggregates.

In the transition functions, we don't really need to recheck this after the
first call.  I had been feeling paranoid about possibly getting a non-null
argument value in some other context; but it's probably game over anyway
if we have a non-null "internal" value that's not what we are expecting.

In the final functions, the general convention in pre-existing final
functions seems to be that an Assert() is good enough, so do it like that
here too.

This seems to save a few tenths of a percent of overall query runtime,
which isn't much, but still it's just overhead if there's not a plausible
case where the checks would fire.

diff --git a/src/backend/utils/adt/orderedsetaggs.c b/src/backend/utils/adt/orderedsetaggs.c
index d98f5a807c8049b4c0d083974b87bbef185ad6ac..216c498a2f18775175bcc3eb6ab6263ee68afe5f 100644 (file)
--- a/src/backend/utils/adt/orderedsetaggs.c
+++ b/src/backend/utils/adt/orderedsetaggs.c
@@ -122,8 +122,8 @@ ordered_set_startup(FunctionCallInfo fcinfo, bool use_tuples)
                int                     numSortCols;
 
                /*
-                * Check we're called as aggregate, and get the Agg node's
-                * group-lifespan context
+                * Check we're called as aggregate (and not a window function), and
+                * get the Agg node's group-lifespan context
                 */
                if (AggCheckCallContext(fcinfo, &gcontext) != AGG_CONTEXT_AGGREGATE)
                        elog(ERROR, "ordered-set aggregate called in non-aggregate context");
@@ -356,12 +356,7 @@ ordered_set_transition(PG_FUNCTION_ARGS)
        if (PG_ARGISNULL(0))
                osastate = ordered_set_startup(fcinfo, false);
        else
-       {
-               /* safety check */
-               if (AggCheckCallContext(fcinfo, NULL) != AGG_CONTEXT_AGGREGATE)
-                       elog(ERROR, "ordered-set aggregate called in non-aggregate context");
                osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
-       }
 
        /* Load the datum into the tuplesort object, but only if it's not null */
        if (!PG_ARGISNULL(1))
@@ -389,12 +384,7 @@ ordered_set_transition_multi(PG_FUNCTION_ARGS)
        if (PG_ARGISNULL(0))
                osastate = ordered_set_startup(fcinfo, true);
        else
-       {
-               /* safety check */
-               if (AggCheckCallContext(fcinfo, NULL) != AGG_CONTEXT_AGGREGATE)
-                       elog(ERROR, "ordered-set aggregate called in non-aggregate context");
                osastate = (OSAPerGroupState *) PG_GETARG_POINTER(0);
-       }
 
        /* Form a tuple from all the other inputs besides the transition value */
        slot = osastate->qstate->tupslot;
@@ -435,9 +425,7 @@ percentile_disc_final(PG_FUNCTION_ARGS)
        bool            isnull;
        int64           rownum;
 
-       /* safety check */
-       if (AggCheckCallContext(fcinfo, NULL) != AGG_CONTEXT_AGGREGATE)
-               elog(ERROR, "ordered-set aggregate called in non-aggregate context");
+       Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
        /* Get and check the percentile argument */
        if (PG_ARGISNULL(1))
@@ -542,9 +530,7 @@ percentile_cont_final_common(FunctionCallInfo fcinfo,
        double          proportion;
        bool            isnull;
 
-       /* safety check */
-       if (AggCheckCallContext(fcinfo, NULL) != AGG_CONTEXT_AGGREGATE)
-               elog(ERROR, "ordered-set aggregate called in non-aggregate context");
+       Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
        /* Get and check the percentile argument */
        if (PG_ARGISNULL(1))
@@ -752,9 +738,7 @@ percentile_disc_multi_final(PG_FUNCTION_ARGS)
        bool            isnull = true;
        int                     i;
 
-       /* safety check */
-       if (AggCheckCallContext(fcinfo, NULL) != AGG_CONTEXT_AGGREGATE)
-               elog(ERROR, "ordered-set aggregate called in non-aggregate context");
+       Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
        /* If there were no regular rows, the result is NULL */
        if (PG_ARGISNULL(0))
@@ -875,9 +859,7 @@ percentile_cont_multi_final_common(FunctionCallInfo fcinfo,
        bool            isnull;
        int                     i;
 
-       /* safety check */
-       if (AggCheckCallContext(fcinfo, NULL) != AGG_CONTEXT_AGGREGATE)
-               elog(ERROR, "ordered-set aggregate called in non-aggregate context");
+       Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
        /* If there were no regular rows, the result is NULL */
        if (PG_ARGISNULL(0))
@@ -1045,9 +1027,7 @@ mode_final(PG_FUNCTION_ARGS)
        FmgrInfo   *equalfn;
        bool            shouldfree;
 
-       /* safety check */
-       if (AggCheckCallContext(fcinfo, NULL) != AGG_CONTEXT_AGGREGATE)
-               elog(ERROR, "ordered-set aggregate called in non-aggregate context");
+       Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
        /* If there were no regular rows, the result is NULL */
        if (PG_ARGISNULL(0))
@@ -1173,9 +1153,7 @@ hypothetical_rank_common(FunctionCallInfo fcinfo, int flag,
        TupleTableSlot *slot;
        int                     i;
 
-       /* safety check */
-       if (AggCheckCallContext(fcinfo, NULL) != AGG_CONTEXT_AGGREGATE)
-               elog(ERROR, "ordered-set aggregate called in non-aggregate context");
+       Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
        /* If there were no regular rows, the rank is always 1 */
        if (PG_ARGISNULL(0))
@@ -1305,9 +1283,7 @@ hypothetical_dense_rank_final(PG_FUNCTION_ARGS)
        MemoryContext tmpcontext;
        int                     i;
 
-       /* safety check */
-       if (AggCheckCallContext(fcinfo, NULL) != AGG_CONTEXT_AGGREGATE)
-               elog(ERROR, "ordered-set aggregate called in non-aggregate context");
+       Assert(AggCheckCallContext(fcinfo, NULL) == AGG_CONTEXT_AGGREGATE);
 
        /* If there were no regular rows, the rank is always 1 */
        if (PG_ARGISNULL(0))