Revise TupleTableSlot code to avoid unnecessary construction and disassembly

of tuples when passing data up through multiple plan nodes.  A slot can now
hold either a normal "physical" HeapTuple, or a "virtual" tuple consisting
of Datum/isnull arrays.  Upper plan levels can usually just copy the Datum
arrays, avoiding heap_formtuple() and possible subsequent nocachegetattr()
calls to extract the data again.  This work extends Atsushi Ogawa's earlier
patch, which provided the key idea of adding Datum arrays to TupleTableSlots.
(I believe however that something like this was foreseen way back in Berkeley
days --- see the old comment on ExecProject.)  A test case involving many
levels of join of fairly wide tables (about 80 columns altogether) showed
about 3x overall speedup, though simple queries will probably not be
helped very much.

I have also duplicated some code in heaptuple.c in order to provide versions
of heap_formtuple and friends that use "bool" arrays to indicate null
attributes, instead of the old convention of "char" arrays containing either
'n' or ' '.  This provides a better match to the convention used by
ExecEvalExpr.  While I have not made a concerted effort to get rid of uses
of the old routines, I think they should be deprecated and eventually removed.

1 files changed, 30 insertions, 53 deletions

diff --git a/src/backend/access/common/printtup.c b/src/backend/access/common/printtup.c
index 3ce44009b91..6f44533822b 100644
--- a/src/backend/access/common/printtup.c
+++ b/src/backend/access/common/printtup.c
@@ -9,7 +9,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/common/printtup.c,v 1.86 2004/12/31 21:59:07 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/common/printtup.c,v 1.87 2005/03/16 21:38:04 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -25,12 +25,9 @@
 
 static void printtup_startup(DestReceiver *self, int operation,
 				 TupleDesc typeinfo);
-static void printtup(HeapTuple tuple, TupleDesc typeinfo,
-		 DestReceiver *self);
-static void printtup_20(HeapTuple tuple, TupleDesc typeinfo,
-			DestReceiver *self);
-static void printtup_internal_20(HeapTuple tuple, TupleDesc typeinfo,
-					 DestReceiver *self);
+static void printtup(TupleTableSlot *slot, DestReceiver *self);
+static void printtup_20(TupleTableSlot *slot, DestReceiver *self);
+static void printtup_internal_20(TupleTableSlot *slot, DestReceiver *self);
 static void printtup_shutdown(DestReceiver *self);
 static void printtup_destroy(DestReceiver *self);
 
@@ -65,8 +62,6 @@ typedef struct
 	TupleDesc	attrinfo;		/* The attr info we are set up for */
 	int			nattrs;
 	PrinttupAttrInfo *myinfo;	/* Cached info about each attr */
-	Datum	   *values;			/* preallocated space for deformtuple */
-	char	   *nulls;
 } DR_printtup;
 
 /* ----------------
@@ -79,7 +74,7 @@ printtup_create_DR(CommandDest dest, Portal portal)
 	DR_printtup *self = (DR_printtup *) palloc(sizeof(DR_printtup));
 
 	if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
-		self->pub.receiveTuple = printtup;
+		self->pub.receiveSlot = printtup;
 	else
 	{
 		/*
@@ -88,9 +83,9 @@ printtup_create_DR(CommandDest dest, Portal portal)
 		 * sufficient to look at the first one.
 		 */
 		if (portal->formats && portal->formats[0] != 0)
-			self->pub.receiveTuple = printtup_internal_20;
+			self->pub.receiveSlot = printtup_internal_20;
 		else
-			self->pub.receiveTuple = printtup_20;
+			self->pub.receiveSlot = printtup_20;
 	}
 	self->pub.rStartup = printtup_startup;
 	self->pub.rShutdown = printtup_shutdown;
@@ -105,8 +100,6 @@ printtup_create_DR(CommandDest dest, Portal portal)
 	self->attrinfo = NULL;
 	self->nattrs = 0;
 	self->myinfo = NULL;
-	self->values = NULL;
-	self->nulls = NULL;
 
 	return (DestReceiver *) self;
 }
@@ -251,12 +244,6 @@ printtup_prepare_info(DR_printtup *myState, TupleDesc typeinfo, int numAttrs)
 	if (myState->myinfo)
 		pfree(myState->myinfo);
 	myState->myinfo = NULL;
-	if (myState->values)
-		pfree(myState->values);
-	myState->values = NULL;
-	if (myState->nulls)
-		pfree(myState->nulls);
-	myState->nulls = NULL;
 
 	myState->attrinfo = typeinfo;
 	myState->nattrs = numAttrs;
@@ -265,8 +252,6 @@ printtup_prepare_info(DR_printtup *myState, TupleDesc typeinfo, int numAttrs)
 
 	myState->myinfo = (PrinttupAttrInfo *)
 		palloc0(numAttrs * sizeof(PrinttupAttrInfo));
-	myState->values = (Datum *) palloc(numAttrs * sizeof(Datum));
-	myState->nulls = (char *) palloc(numAttrs * sizeof(char));
 
 	for (i = 0; i < numAttrs; i++)
 	{
@@ -302,8 +287,9 @@ printtup_prepare_info(DR_printtup *myState, TupleDesc typeinfo, int numAttrs)
  * ----------------
  */
 static void
-printtup(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
+printtup(TupleTableSlot *slot, DestReceiver *self)
 {
+	TupleDesc typeinfo = slot->tts_tupleDescriptor;
 	DR_printtup *myState = (DR_printtup *) self;
 	StringInfoData buf;
 	int			natts = typeinfo->natts;
@@ -313,10 +299,8 @@ printtup(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
 	if (myState->attrinfo != typeinfo || myState->nattrs != natts)
 		printtup_prepare_info(myState, typeinfo, natts);
 
-	/*
-	 * deconstruct the tuple (faster than a heap_getattr loop)
-	 */
-	heap_deformtuple(tuple, typeinfo, myState->values, myState->nulls);
+	/* Make sure the tuple is fully deconstructed */
+	slot_getallattrs(slot);
 
 	/*
 	 * Prepare a DataRow message
@@ -331,10 +315,10 @@ printtup(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
 	for (i = 0; i < natts; ++i)
 	{
 		PrinttupAttrInfo *thisState = myState->myinfo + i;
-		Datum		origattr = myState->values[i],
+		Datum		origattr = slot->tts_values[i],
 					attr;
 
-		if (myState->nulls[i] == 'n')
+		if (slot->tts_isnull[i])
 		{
 			pq_sendint(&buf, -1, 4);
 			continue;
@@ -389,8 +373,9 @@ printtup(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
  * ----------------
  */
 static void
-printtup_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
+printtup_20(TupleTableSlot *slot, DestReceiver *self)
 {
+	TupleDesc typeinfo = slot->tts_tupleDescriptor;
 	DR_printtup *myState = (DR_printtup *) self;
 	StringInfoData buf;
 	int			natts = typeinfo->natts;
@@ -402,10 +387,8 @@ printtup_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
 	if (myState->attrinfo != typeinfo || myState->nattrs != natts)
 		printtup_prepare_info(myState, typeinfo, natts);
 
-	/*
-	 * deconstruct the tuple (faster than a heap_getattr loop)
-	 */
-	heap_deformtuple(tuple, typeinfo, myState->values, myState->nulls);
+	/* Make sure the tuple is fully deconstructed */
+	slot_getallattrs(slot);
 
 	/*
 	 * tell the frontend to expect new tuple data (in ASCII style)
@@ -419,7 +402,7 @@ printtup_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
 	k = 1 << 7;
 	for (i = 0; i < natts; ++i)
 	{
-		if (myState->nulls[i] != 'n')
+		if (slot->tts_isnull[i])
 			j |= k;				/* set bit if not null */
 		k >>= 1;
 		if (k == 0)				/* end of byte? */
@@ -438,11 +421,11 @@ printtup_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
 	for (i = 0; i < natts; ++i)
 	{
 		PrinttupAttrInfo *thisState = myState->myinfo + i;
-		Datum		origattr = myState->values[i],
+		Datum		origattr = slot->tts_values[i],
 					attr;
 		char	   *outputstr;
 
-		if (myState->nulls[i] == 'n')
+		if (slot->tts_isnull[i])
 			continue;
 
 		Assert(thisState->format == 0);
@@ -483,12 +466,6 @@ printtup_shutdown(DestReceiver *self)
 	if (myState->myinfo)
 		pfree(myState->myinfo);
 	myState->myinfo = NULL;
-	if (myState->values)
-		pfree(myState->values);
-	myState->values = NULL;
-	if (myState->nulls)
-		pfree(myState->nulls);
-	myState->nulls = NULL;
 
 	myState->attrinfo = NULL;
 }
@@ -548,8 +525,9 @@ debugStartup(DestReceiver *self, int operation, TupleDesc typeinfo)
  * ----------------
  */
 void
-debugtup(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
+debugtup(TupleTableSlot *slot, DestReceiver *self)
 {
+	TupleDesc	typeinfo = slot->tts_tupleDescriptor;
 	int			natts = typeinfo->natts;
 	int			i;
 	Datum		origattr,
@@ -562,7 +540,7 @@ debugtup(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
 
 	for (i = 0; i < natts; ++i)
 	{
-		origattr = heap_getattr(tuple, i + 1, typeinfo, &isnull);
+		origattr = slot_getattr(slot, i + 1, &isnull);
 		if (isnull)
 			continue;
 		getTypeOutputInfo(typeinfo->attrs[i]->atttypid,
@@ -603,8 +581,9 @@ debugtup(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
  * ----------------
  */
 static void
-printtup_internal_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
+printtup_internal_20(TupleTableSlot *slot, DestReceiver *self)
 {
+	TupleDesc typeinfo = slot->tts_tupleDescriptor;
 	DR_printtup *myState = (DR_printtup *) self;
 	StringInfoData buf;
 	int			natts = typeinfo->natts;
@@ -616,10 +595,8 @@ printtup_internal_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
 	if (myState->attrinfo != typeinfo || myState->nattrs != natts)
 		printtup_prepare_info(myState, typeinfo, natts);
 
-	/*
-	 * deconstruct the tuple (faster than a heap_getattr loop)
-	 */
-	heap_deformtuple(tuple, typeinfo, myState->values, myState->nulls);
+	/* Make sure the tuple is fully deconstructed */
+	slot_getallattrs(slot);
 
 	/*
 	 * tell the frontend to expect new tuple data (in binary style)
@@ -633,7 +610,7 @@ printtup_internal_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
 	k = 1 << 7;
 	for (i = 0; i < natts; ++i)
 	{
-		if (myState->nulls[i] != 'n')
+		if (slot->tts_isnull[i])
 			j |= k;				/* set bit if not null */
 		k >>= 1;
 		if (k == 0)				/* end of byte? */
@@ -652,11 +629,11 @@ printtup_internal_20(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self)
 	for (i = 0; i < natts; ++i)
 	{
 		PrinttupAttrInfo *thisState = myState->myinfo + i;
-		Datum		origattr = myState->values[i],
+		Datum		origattr = slot->tts_values[i],
 					attr;
 		bytea	   *outputbytes;
 
-		if (myState->nulls[i] == 'n')
+		if (slot->tts_isnull[i])
 			continue;
 
 		Assert(thisState->format == 1);