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Resurrect heap_deformtuple(), this time implemented as a singly nested
loop over the fields instead of a loop around heap_getattr. This is considerably faster (O(N) instead of O(N^2)) when there are nulls or varlena fields, since those prevent use of attcacheoff. Replace loops over heap_getattr with heap_deformtuple in situations where all or most of the fields have to be fetched, such as printtup and tuptoaster. Profiling done more than a year ago shows that this should be a nice win for situations involving many-column tables.
1 parent af44cac commit 8f2ea8b

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8 files changed

+314
-208
lines changed

8 files changed

+314
-208
lines changed

‎src/backend/access/common/heaptuple.c

Lines changed: 166 additions & 114 deletions
Large diffs are not rendered by default.

‎src/backend/access/common/printtup.c

Lines changed: 48 additions & 16 deletions
Original file line numberDiff line numberDiff line change
@@ -9,7 +9,7 @@
99
* Portions Copyright (c) 1994, Regents of the University of California
1010
*
1111
* IDENTIFICATION
12-
* $PostgreSQL: pgsql/src/backend/access/common/printtup.c,v 1.81 2004/05/26 04:41:03 neilc Exp $
12+
* $PostgreSQL: pgsql/src/backend/access/common/printtup.c,v 1.82 2004/06/04 20:35:21 tgl Exp $
1313
*
1414
*-------------------------------------------------------------------------
1515
*/
@@ -65,6 +65,8 @@ typedef struct
6565
TupleDesc attrinfo; /* The attr info we are set up for */
6666
int nattrs;
6767
PrinttupAttrInfo *myinfo; /* Cached info about each attr */
68+
Datum *values; /* preallocated space for deformtuple */
69+
char *nulls;
6870
} DR_printtup;
6971

7072
/* ----------------
@@ -103,6 +105,8 @@ printtup_create_DR(CommandDest dest, Portal portal)
103105
self->attrinfo = NULL;
104106
self->nattrs = 0;
105107
self->myinfo = NULL;
108+
self->values = NULL;
109+
self->nulls = NULL;
106110

107111
return (DestReceiver *) self;
108112
}
@@ -243,15 +247,27 @@ printtup_prepare_info(DR_printtup *myState, TupleDesc typeinfo, int numAttrs)
243247
int16 *formats = myState->portal->formats;
244248
int i;
245249

250+
/* get rid of any old data */
246251
if (myState->myinfo)
247-
pfree(myState->myinfo); /* get rid of any old data */
252+
pfree(myState->myinfo);
248253
myState->myinfo = NULL;
254+
if (myState->values)
255+
pfree(myState->values);
256+
myState->values = NULL;
257+
if (myState->nulls)
258+
pfree(myState->nulls);
259+
myState->nulls = NULL;
260+
249261
myState->attrinfo = typeinfo;
250262
myState->nattrs = numAttrs;
251263
if (numAttrs <= 0)
252264
return;
265+
253266
myState->myinfo = (PrinttupAttrInfo *)
254267
palloc0(numAttrs * sizeof(PrinttupAttrInfo));
268+
myState->values = (Datum *) palloc(numAttrs * sizeof(Datum));
269+
myState->nulls = (char *) palloc(numAttrs * sizeof(char));
270+
255271
for (i = 0; i < numAttrs; i++)
256272
{
257273
PrinttupAttrInfo *thisState = myState->myinfo + i;
@@ -297,6 +313,11 @@ printtup(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
297313
if (myState->attrinfo != typeinfo || myState->nattrs != natts)
298314
printtup_prepare_info(myState, typeinfo, natts);
299315

316+
/*
317+
* deconstruct the tuple (faster than a heap_getattr loop)
318+
*/
319+
heap_deformtuple(tuple, typeinfo, myState->values, myState->nulls);
320+
300321
/*
301322
* Prepare a DataRow message
302323
*/
@@ -310,12 +331,10 @@ printtup(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
310331
for (i = 0; i < natts; ++i)
311332
{
312333
PrinttupAttrInfo *thisState = myState->myinfo + i;
313-
Datum origattr,
334+
Datum origattr = myState->values[i],
314335
attr;
315-
bool isnull;
316336

317-
origattr = heap_getattr(tuple, i + 1, typeinfo, &isnull);
318-
if (isnull)
337+
if (myState->nulls[i] == 'n')
319338
{
320339
pq_sendint(&buf, -1, 4);
321340
continue;
@@ -383,6 +402,11 @@ printtup_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
383402
if (myState->attrinfo != typeinfo || myState->nattrs != natts)
384403
printtup_prepare_info(myState, typeinfo, natts);
385404

405+
/*
406+
* deconstruct the tuple (faster than a heap_getattr loop)
407+
*/
408+
heap_deformtuple(tuple, typeinfo, myState->values, myState->nulls);
409+
386410
/*
387411
* tell the frontend to expect new tuple data (in ASCII style)
388412
*/
@@ -395,7 +419,7 @@ printtup_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
395419
k = 1 << 7;
396420
for (i = 0; i < natts; ++i)
397421
{
398-
if (!heap_attisnull(tuple, i + 1))
422+
if (myState->nulls[i] != 'n')
399423
j |= k; /* set bit if not null */
400424
k >>= 1;
401425
if (k == 0) /* end of byte? */
@@ -414,13 +438,11 @@ printtup_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
414438
for (i = 0; i < natts; ++i)
415439
{
416440
PrinttupAttrInfo *thisState = myState->myinfo + i;
417-
Datum origattr,
441+
Datum origattr = myState->values[i],
418442
attr;
419-
bool isnull;
420443
char *outputstr;
421444

422-
origattr = heap_getattr(tuple, i + 1, typeinfo, &isnull);
423-
if (isnull)
445+
if (myState->nulls[i] == 'n')
424446
continue;
425447

426448
Assert(thisState->format == 0);
@@ -461,6 +483,13 @@ printtup_shutdown(DestReceiver *self)
461483
if (myState->myinfo)
462484
pfree(myState->myinfo);
463485
myState->myinfo = NULL;
486+
if (myState->values)
487+
pfree(myState->values);
488+
myState->values = NULL;
489+
if (myState->nulls)
490+
pfree(myState->nulls);
491+
myState->nulls = NULL;
492+
464493
myState->attrinfo = NULL;
465494
}
466495

@@ -587,6 +616,11 @@ printtup_internal_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
587616
if (myState->attrinfo != typeinfo || myState->nattrs != natts)
588617
printtup_prepare_info(myState, typeinfo, natts);
589618

619+
/*
620+
* deconstruct the tuple (faster than a heap_getattr loop)
621+
*/
622+
heap_deformtuple(tuple, typeinfo, myState->values, myState->nulls);
623+
590624
/*
591625
* tell the frontend to expect new tuple data (in binary style)
592626
*/
@@ -599,7 +633,7 @@ printtup_internal_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
599633
k = 1 << 7;
600634
for (i = 0; i < natts; ++i)
601635
{
602-
if (!heap_attisnull(tuple, i + 1))
636+
if (myState->nulls[i] != 'n')
603637
j |= k; /* set bit if not null */
604638
k >>= 1;
605639
if (k == 0) /* end of byte? */
@@ -618,13 +652,11 @@ printtup_internal_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
618652
for (i = 0; i < natts; ++i)
619653
{
620654
PrinttupAttrInfo *thisState = myState->myinfo + i;
621-
Datum origattr,
655+
Datum origattr = myState->values[i],
622656
attr;
623-
bool isnull;
624657
bytea *outputbytes;
625658

626-
origattr = heap_getattr(tuple, i + 1, typeinfo, &isnull);
627-
if (isnull)
659+
if (myState->nulls[i] == 'n')
628660
continue;
629661

630662
Assert(thisState->format == 1);

‎src/backend/access/heap/tuptoaster.c

Lines changed: 41 additions & 29 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.41 2003/11/29 19:51:40 pgsql Exp $
11+
* $PostgreSQL: pgsql/src/backend/access/heap/tuptoaster.c,v 1.42 2004/06/04 20:35:21 tgl Exp $
1212
*
1313
*
1414
* INTERFACE ROUTINES
@@ -281,15 +281,26 @@ toast_delete(Relation rel, HeapTuple oldtup)
281281
Form_pg_attribute *att;
282282
int numAttrs;
283283
int i;
284-
Datum value;
285-
bool isnull;
284+
Datum toast_values[MaxHeapAttributeNumber];
285+
char toast_nulls[MaxHeapAttributeNumber];
286286

287287
/*
288-
* Get the tuple descriptor, the number of and attribute descriptors.
288+
* Get the tuple descriptor and break down the tuple into fields.
289+
*
290+
* NOTE: it's debatable whether to use heap_deformtuple() here or
291+
* just heap_getattr() only the varlena columns. The latter could
292+
* win if there are few varlena columns and many non-varlena ones.
293+
* However, heap_deformtuple costs only O(N) while the heap_getattr
294+
* way would cost O(N^2) if there are many varlena columns, so it
295+
* seems better to err on the side of linear cost. (We won't even
296+
* be here unless there's at least one varlena column, by the way.)
289297
*/
290298
tupleDesc = rel->rd_att;
291-
numAttrs = tupleDesc->natts;
292299
att = tupleDesc->attrs;
300+
numAttrs = tupleDesc->natts;
301+
302+
Assert(numAttrs <= MaxHeapAttributeNumber);
303+
heap_deformtuple(oldtup, tupleDesc, toast_values, toast_nulls);
293304

294305
/*
295306
* Check for external stored attributes and delete them from the
@@ -299,8 +310,9 @@ toast_delete(Relation rel, HeapTuple oldtup)
299310
{
300311
if (att[i]->attlen == -1)
301312
{
302-
value = heap_getattr(oldtup, i + 1, tupleDesc, &isnull);
303-
if (!isnull && VARATT_IS_EXTERNAL(value))
313+
Datum value = toast_values[i];
314+
315+
if (toast_nulls[i] != 'n' && VARATT_IS_EXTERNAL(value))
304316
toast_delete_datum(rel, value);
305317
}
306318
}
@@ -321,8 +333,6 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup)
321333
Form_pg_attribute *att;
322334
int numAttrs;
323335
int i;
324-
bool old_isnull;
325-
bool new_isnull;
326336

327337
bool need_change = false;
328338
bool need_free = false;
@@ -333,18 +343,24 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup)
333343

334344
char toast_action[MaxHeapAttributeNumber];
335345
char toast_nulls[MaxHeapAttributeNumber];
346+
char toast_oldnulls[MaxHeapAttributeNumber];
336347
Datum toast_values[MaxHeapAttributeNumber];
348+
Datum toast_oldvalues[MaxHeapAttributeNumber];
337349
int32 toast_sizes[MaxHeapAttributeNumber];
338350
bool toast_free[MaxHeapAttributeNumber];
339351
bool toast_delold[MaxHeapAttributeNumber];
340352

341353
/*
342-
* Get the tuple descriptor, the number of and attribute descriptors
343-
* and the location of the tuple values.
354+
* Get the tuple descriptor and break down the tuple(s) into fields.
344355
*/
345356
tupleDesc = rel->rd_att;
346-
numAttrs = tupleDesc->natts;
347357
att = tupleDesc->attrs;
358+
numAttrs = tupleDesc->natts;
359+
360+
Assert(numAttrs <= MaxHeapAttributeNumber);
361+
heap_deformtuple(newtup, tupleDesc, toast_values, toast_nulls);
362+
if (oldtup != NULL)
363+
heap_deformtuple(oldtup, tupleDesc, toast_oldvalues, toast_oldnulls);
348364

349365
/* ----------
350366
* Then collect information about the values given
@@ -353,12 +369,15 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup)
353369
* ' ' default handling
354370
* 'p' already processed --- don't touch it
355371
* 'x' incompressible, but OK to move off
372+
*
373+
* NOTE: toast_sizes[i] is only made valid for varlena attributes with
374+
* toast_action[i] different from 'p'.
356375
* ----------
357376
*/
358377
memset(toast_action, ' ', numAttrs * sizeof(char));
359-
memset(toast_nulls, ' ', numAttrs * sizeof(char));
360378
memset(toast_free, 0, numAttrs * sizeof(bool));
361379
memset(toast_delold, 0, numAttrs * sizeof(bool));
380+
362381
for (i = 0; i < numAttrs; i++)
363382
{
364383
varattrib *old_value;
@@ -369,27 +388,24 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup)
369388
/*
370389
* For UPDATE get the old and new values of this attribute
371390
*/
372-
old_value = (varattrib *) DatumGetPointer(
373-
heap_getattr(oldtup, i + 1, tupleDesc, &old_isnull));
374-
toast_values[i] =
375-
heap_getattr(newtup, i + 1, tupleDesc, &new_isnull);
391+
old_value = (varattrib *) DatumGetPointer(toast_oldvalues[i]);
376392
new_value = (varattrib *) DatumGetPointer(toast_values[i]);
377393

378394
/*
379395
* If the old value is an external stored one, check if it has
380396
* changed so we have to delete it later.
381397
*/
382-
if (!old_isnull && att[i]->attlen == -1 &&
398+
if (att[i]->attlen == -1 && toast_oldnulls[i] != 'n' &&
383399
VARATT_IS_EXTERNAL(old_value))
384400
{
385-
if (new_isnull || !VARATT_IS_EXTERNAL(new_value) ||
401+
if (toast_nulls[i] == 'n' || !VARATT_IS_EXTERNAL(new_value) ||
386402
old_value->va_content.va_external.va_valueid !=
387403
new_value->va_content.va_external.va_valueid ||
388404
old_value->va_content.va_external.va_toastrelid !=
389405
new_value->va_content.va_external.va_toastrelid)
390406
{
391407
/*
392-
* The old external store value isn't needed any more
408+
* The old external stored value isn't needed any more
393409
* after the update
394410
*/
395411
toast_delold[i] = true;
@@ -413,23 +429,21 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup)
413429
/*
414430
* For INSERT simply get the new value
415431
*/
416-
toast_values[i] =
417-
heap_getattr(newtup, i + 1, tupleDesc, &new_isnull);
432+
new_value = (varattrib *) DatumGetPointer(toast_values[i]);
418433
}
419434

420435
/*
421436
* Handle NULL attributes
422437
*/
423-
if (new_isnull)
438+
if (toast_nulls[i] == 'n')
424439
{
425440
toast_action[i] = 'p';
426-
toast_nulls[i] = 'n';
427441
has_nulls = true;
428442
continue;
429443
}
430444

431445
/*
432-
* Now look at varsize attributes
446+
* Now look at varlena attributes
433447
*/
434448
if (att[i]->attlen == -1)
435449
{
@@ -461,10 +475,9 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup)
461475
else
462476
{
463477
/*
464-
* Not a variable size attribute, plain storage always
478+
* Not a varlena attribute, plain storage always
465479
*/
466480
toast_action[i] = 'p';
467-
toast_sizes[i] = att[i]->attlen;
468481
}
469482
}
470483

@@ -768,8 +781,7 @@ toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup)
768781
if (need_delold)
769782
for (i = 0; i < numAttrs; i++)
770783
if (toast_delold[i])
771-
toast_delete_datum(rel,
772-
heap_getattr(oldtup, i + 1, tupleDesc, &old_isnull));
784+
toast_delete_datum(rel, toast_oldvalues[i]);
773785
}
774786

775787

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