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11 | 11 | * SQL aggregates. (Do not expect POSTQUEL semantics.) -- ay 2/95 |
12 | 12 | * |
13 | 13 | * IDENTIFICATION |
14 | | - * $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.55 1999/09/26 21:21:09 tgl Exp $ |
| 14 | + * $Header: /cvsroot/pgsql/src/backend/executor/nodeAgg.c,v 1.56 1999/09/28 02:03:19 tgl Exp $ |
15 | 15 | * |
16 | 16 | *------------------------------------------------------------------------- |
17 | 17 | */ |
@@ -373,7 +373,8 @@ ExecAgg(Agg *node) |
373 | 373 | elog(ERROR,"ExecAgg: no valid transition functions??"); |
374 | 374 |
|
375 | 375 | /* |
376 | | - * Release any per-group working storage. |
| 376 | + * Release any per-group working storage, unless we're passing |
| 377 | + * it back as the result of the aggregate. |
377 | 378 | */ |
378 | 379 | if (OidIsValid(peraggstate->xfn1_oid)&& |
379 | 380 | !peraggstate->value1IsNull&& |
@@ -411,34 +412,20 @@ ExecAgg(Agg *node) |
411 | 412 | aggstate->agg_done= true; |
412 | 413 |
|
413 | 414 | /* |
414 | | - * When the outerPlan doesn't return a single tuple, |
415 | | - * create a dummy input tuple anyway because we still need |
416 | | - * to return a valid aggregate tuple. (XXX isn't this wasted |
417 | | - * effort? Since we're not in GROUP BY mode, it shouldn't be |
418 | | - * possible for the projected result to refer to any raw input |
419 | | - * columns??) The values returned for the aggregates will be |
420 | | - * the initial values of the transition functions. |
| 415 | + * We used to create a dummy all-nulls input tuple here if |
| 416 | + * inputTuple == NULL (ie, the outerPlan didn't return anything). |
| 417 | + * However, now that we don't return a bogus tuple in Group mode, |
| 418 | + * we can only get here with inputTuple == NULL in non-Group mode. |
| 419 | + * So, if the parser has done its job right, the projected output |
| 420 | + * tuple's targetList must not contain any direct references to |
| 421 | + * input columns, and so it's a waste of time to create an |
| 422 | + * all-nulls input tuple. We just let the tuple slot get set |
| 423 | + * to NULL instead. The values returned for the aggregates will |
| 424 | + * be the initial values of the transition functions. |
421 | 425 | */ |
422 | | -if (inputTuple==NULL) |
423 | | -{ |
424 | | -TupleDesctupType; |
425 | | -Datum*tupValue; |
426 | | -char*null_array; |
427 | | -AttrNumberattnum; |
428 | | - |
429 | | -tupType=aggstate->csstate.css_ScanTupleSlot->ttc_tupleDescriptor; |
430 | | -tupValue=projInfo->pi_tupValue; |
431 | | - |
432 | | -/* set all the values to NULL */ |
433 | | -null_array=palloc(sizeof(char)*tupType->natts); |
434 | | -for (attnum=0;attnum<tupType->natts;attnum++) |
435 | | -null_array[attnum]='n'; |
436 | | -inputTuple=heap_formtuple(tupType,tupValue,null_array); |
437 | | -pfree(null_array); |
438 | | -} |
439 | 426 |
|
440 | 427 | /* |
441 | | - * Store the representative input tuple (orfaked-up null tuple) |
| 428 | + * Store the representative input tuple (orNULL, if none) |
442 | 429 | * in the tuple table slot reserved for it. |
443 | 430 | */ |
444 | 431 | ExecStoreTuple(inputTuple, |
|