Revert "Introduce CompactAttribute array in TupleDesc"

This reverts commit d28dff3f6cd6a7562fb2c211ac0fb74a33ffd032.

Quite a large number of buildfarm members didn't like this commit and
it's not yet clear why.  Reverting this before too many animals turn
red.

Discussion: https://postgr.es/m/CAApHDvr9i6T5=iAwQCxFDgMsthr_obVxgwBaEJkC8KUH6yM3Hw@mail.gmail.com

3 files changed, 48 insertions, 101 deletions

diff --git a/src/backend/access/common/heaptuple.c b/src/backend/access/common/heaptuple.c
index 982e7222c49..9e3407bf987 100644
--- a/src/backend/access/common/heaptuple.c
+++ b/src/backend/access/common/heaptuple.c
@@ -83,10 +83,6 @@
 #define VARLENA_ATT_IS_PACKABLE(att) \
 	((att)->attstorage != TYPSTORAGE_PLAIN)
 
-/* FormData_pg_attribute.attstorage != TYPSTORAGE_PLAIN and an attlen of -1 */
-#define COMPACT_ATTR_IS_PACKABLE(att) \
-	((att)->attlen == -1 && (att)->attispackable)
-
 /*
  * Setup for caching pass-by-ref missing attributes in a way that survives
  * tupleDesc destruction.
@@ -151,12 +147,12 @@ Datum
 getmissingattr(TupleDesc tupleDesc,
 			   int attnum, bool *isnull)
 {
-	CompactAttribute *att;
+	Form_pg_attribute att;
 
 	Assert(attnum <= tupleDesc->natts);
 	Assert(attnum > 0);
 
-	att = TupleDescCompactAttr(tupleDesc, attnum - 1);
+	att = TupleDescAttr(tupleDesc, attnum - 1);
 
 	if (att->atthasmissing)
 	{
@@ -227,15 +223,15 @@ heap_compute_data_size(TupleDesc tupleDesc,
 	for (i = 0; i < numberOfAttributes; i++)
 	{
 		Datum		val;
-		CompactAttribute *atti;
+		Form_pg_attribute atti;
 
 		if (isnull[i])
 			continue;
 
 		val = values[i];
-		atti = TupleDescCompactAttr(tupleDesc, i);
+		atti = TupleDescAttr(tupleDesc, i);
 
-		if (COMPACT_ATTR_IS_PACKABLE(atti) &&
+		if (ATT_IS_PACKABLE(atti) &&
 			VARATT_CAN_MAKE_SHORT(DatumGetPointer(val)))
 		{
 			/*
@@ -272,7 +268,7 @@ heap_compute_data_size(TupleDesc tupleDesc,
  * Fill in either a data value or a bit in the null bitmask
  */
 static inline void
-fill_val(CompactAttribute *att,
+fill_val(Form_pg_attribute att,
 		 bits8 **bit,
 		 int *bitmask,
 		 char **dataP,
@@ -353,7 +349,8 @@ fill_val(CompactAttribute *att,
 			data_length = VARSIZE_SHORT(val);
 			memcpy(data, val, data_length);
 		}
-		else if (att->attispackable && VARATT_CAN_MAKE_SHORT(val))
+		else if (VARLENA_ATT_IS_PACKABLE(att) &&
+				 VARATT_CAN_MAKE_SHORT(val))
 		{
 			/* convert to short varlena -- no alignment */
 			data_length = VARATT_CONVERTED_SHORT_SIZE(val);
@@ -430,7 +427,7 @@ heap_fill_tuple(TupleDesc tupleDesc,
 
 	for (i = 0; i < numberOfAttributes; i++)
 	{
-		CompactAttribute *attr = TupleDescCompactAttr(tupleDesc, i);
+		Form_pg_attribute attr = TupleDescAttr(tupleDesc, i);
 
 		fill_val(attr,
 				 bitP ? &bitP : NULL,
@@ -464,8 +461,7 @@ heap_attisnull(HeapTuple tup, int attnum, TupleDesc tupleDesc)
 	Assert(!tupleDesc || attnum <= tupleDesc->natts);
 	if (attnum > (int) HeapTupleHeaderGetNatts(tup->t_data))
 	{
-		if (tupleDesc &&
-			TupleDescCompactAttr(tupleDesc, attnum - 1)->atthasmissing)
+		if (tupleDesc && TupleDescAttr(tupleDesc, attnum - 1)->atthasmissing)
 			return false;
 		else
 			return true;
@@ -574,13 +570,13 @@ nocachegetattr(HeapTuple tup,
 
 	if (!slow)
 	{
-		CompactAttribute *att;
+		Form_pg_attribute att;
 
 		/*
 		 * If we get here, there are no nulls up to and including the target
 		 * attribute.  If we have a cached offset, we can use it.
 		 */
-		att = TupleDescCompactAttr(tupleDesc, attnum);
+		att = TupleDescAttr(tupleDesc, attnum);
 		if (att->attcacheoff >= 0)
 			return fetchatt(att, tp + att->attcacheoff);
 
@@ -595,7 +591,7 @@ nocachegetattr(HeapTuple tup,
 
 			for (j = 0; j <= attnum; j++)
 			{
-				if (TupleDescCompactAttr(tupleDesc, j)->attlen <= 0)
+				if (TupleDescAttr(tupleDesc, j)->attlen <= 0)
 				{
 					slow = true;
 					break;
@@ -618,18 +614,18 @@ nocachegetattr(HeapTuple tup,
 		 * fixed-width columns, in hope of avoiding future visits to this
 		 * routine.
 		 */
-		TupleDescCompactAttr(tupleDesc, 0)->attcacheoff = 0;
+		TupleDescAttr(tupleDesc, 0)->attcacheoff = 0;
 
 		/* we might have set some offsets in the slow path previously */
-		while (j < natts && TupleDescCompactAttr(tupleDesc, j)->attcacheoff > 0)
+		while (j < natts && TupleDescAttr(tupleDesc, j)->attcacheoff > 0)
 			j++;
 
-		off = TupleDescCompactAttr(tupleDesc, j - 1)->attcacheoff +
-			TupleDescCompactAttr(tupleDesc, j - 1)->attlen;
+		off = TupleDescAttr(tupleDesc, j - 1)->attcacheoff +
+			TupleDescAttr(tupleDesc, j - 1)->attlen;
 
 		for (; j < natts; j++)
 		{
-			CompactAttribute *att = TupleDescCompactAttr(tupleDesc, j);
+			Form_pg_attribute att = TupleDescAttr(tupleDesc, j);
 
 			if (att->attlen <= 0)
 				break;
@@ -643,7 +639,7 @@ nocachegetattr(HeapTuple tup,
 
 		Assert(j > attnum);
 
-		off = TupleDescCompactAttr(tupleDesc, attnum)->attcacheoff;
+		off = TupleDescAttr(tupleDesc, attnum)->attcacheoff;
 	}
 	else
 	{
@@ -663,7 +659,7 @@ nocachegetattr(HeapTuple tup,
 		off = 0;
 		for (i = 0;; i++)		/* loop exit is at "break" */
 		{
-			CompactAttribute *att = TupleDescCompactAttr(tupleDesc, i);
+			Form_pg_attribute att = TupleDescAttr(tupleDesc, i);
 
 			if (HeapTupleHasNulls(tup) && att_isnull(i, bp))
 			{
@@ -711,7 +707,7 @@ nocachegetattr(HeapTuple tup,
 		}
 	}
 
-	return fetchatt(TupleDescCompactAttr(tupleDesc, attnum), tp + off);
+	return fetchatt(TupleDescAttr(tupleDesc, attnum), tp + off);
 }
 
 /* ----------------
@@ -896,7 +892,7 @@ expand_tuple(HeapTuple *targetHeapTuple,
 		{
 			if (attrmiss[attnum].am_present)
 			{
-				CompactAttribute *att = TupleDescCompactAttr(tupleDesc, attnum);
+				Form_pg_attribute att = TupleDescAttr(tupleDesc, attnum);
 
 				targetDataLen = att_align_datum(targetDataLen,
 												att->attalign,
@@ -1024,7 +1020,8 @@ expand_tuple(HeapTuple *targetHeapTuple,
 	/* Now fill in the missing values */
 	for (attnum = sourceNatts; attnum < natts; attnum++)
 	{
-		CompactAttribute *attr = TupleDescCompactAttr(tupleDesc, attnum);
+
+		Form_pg_attribute attr = TupleDescAttr(tupleDesc, attnum);
 
 		if (attrmiss && attrmiss[attnum].am_present)
 		{
@@ -1373,7 +1370,7 @@ heap_deform_tuple(HeapTuple tuple, TupleDesc tupleDesc,
 
 	for (attnum = 0; attnum < natts; attnum++)
 	{
-		CompactAttribute *thisatt = TupleDescCompactAttr(tupleDesc, attnum);
+		Form_pg_attribute thisatt = TupleDescAttr(tupleDesc, attnum);
 
 		if (hasnulls && att_isnull(attnum, bp))
 		{
diff --git a/src/backend/access/common/indextuple.c b/src/backend/access/common/indextuple.c
index 37133ed7f80..bb2c6a2bcc1 100644
--- a/src/backend/access/common/indextuple.c
+++ b/src/backend/access/common/indextuple.c
@@ -303,13 +303,13 @@ nocache_index_getattr(IndexTuple tup,
 
 	if (!slow)
 	{
-		CompactAttribute *att;
+		Form_pg_attribute att;
 
 		/*
 		 * If we get here, there are no nulls up to and including the target
 		 * attribute.  If we have a cached offset, we can use it.
 		 */
-		att = TupleDescCompactAttr(tupleDesc, attnum);
+		att = TupleDescAttr(tupleDesc, attnum);
 		if (att->attcacheoff >= 0)
 			return fetchatt(att, tp + att->attcacheoff);
 
@@ -324,7 +324,7 @@ nocache_index_getattr(IndexTuple tup,
 
 			for (j = 0; j <= attnum; j++)
 			{
-				if (TupleDescCompactAttr(tupleDesc, j)->attlen <= 0)
+				if (TupleDescAttr(tupleDesc, j)->attlen <= 0)
 				{
 					slow = true;
 					break;
@@ -347,18 +347,18 @@ nocache_index_getattr(IndexTuple tup,
 		 * fixed-width columns, in hope of avoiding future visits to this
 		 * routine.
 		 */
-		TupleDescCompactAttr(tupleDesc, 0)->attcacheoff = 0;
+		TupleDescAttr(tupleDesc, 0)->attcacheoff = 0;
 
 		/* we might have set some offsets in the slow path previously */
-		while (j < natts && TupleDescCompactAttr(tupleDesc, j)->attcacheoff > 0)
+		while (j < natts && TupleDescAttr(tupleDesc, j)->attcacheoff > 0)
 			j++;
 
-		off = TupleDescCompactAttr(tupleDesc, j - 1)->attcacheoff +
-			TupleDescCompactAttr(tupleDesc, j - 1)->attlen;
+		off = TupleDescAttr(tupleDesc, j - 1)->attcacheoff +
+			TupleDescAttr(tupleDesc, j - 1)->attlen;
 
 		for (; j < natts; j++)
 		{
-			CompactAttribute *att = TupleDescCompactAttr(tupleDesc, j);
+			Form_pg_attribute att = TupleDescAttr(tupleDesc, j);
 
 			if (att->attlen <= 0)
 				break;
@@ -372,7 +372,7 @@ nocache_index_getattr(IndexTuple tup,
 
 		Assert(j > attnum);
 
-		off = TupleDescCompactAttr(tupleDesc, attnum)->attcacheoff;
+		off = TupleDescAttr(tupleDesc, attnum)->attcacheoff;
 	}
 	else
 	{
@@ -392,7 +392,7 @@ nocache_index_getattr(IndexTuple tup,
 		off = 0;
 		for (i = 0;; i++)		/* loop exit is at "break" */
 		{
-			CompactAttribute *att = TupleDescCompactAttr(tupleDesc, i);
+			Form_pg_attribute att = TupleDescAttr(tupleDesc, i);
 
 			if (IndexTupleHasNulls(tup) && att_isnull(i, bp))
 			{
@@ -440,7 +440,7 @@ nocache_index_getattr(IndexTuple tup,
 		}
 	}
 
-	return fetchatt(TupleDescCompactAttr(tupleDesc, attnum), tp + off);
+	return fetchatt(TupleDescAttr(tupleDesc, attnum), tp + off);
 }
 
 /*
@@ -490,7 +490,7 @@ index_deform_tuple_internal(TupleDesc tupleDescriptor,
 
 	for (attnum = 0; attnum < natts; attnum++)
 	{
-		CompactAttribute *thisatt = TupleDescCompactAttr(tupleDescriptor, attnum);
+		Form_pg_attribute thisatt = TupleDescAttr(tupleDescriptor, attnum);
 
 		if (hasnulls && att_isnull(attnum, bp))
 		{
@@ -588,7 +588,7 @@ index_truncate_tuple(TupleDesc sourceDescriptor, IndexTuple source,
 		return CopyIndexTuple(source);
 
 	/* Create temporary descriptor to scribble on */
-	truncdesc = CreateTemplateTupleDesc(sourceDescriptor->natts);
+	truncdesc = palloc(TupleDescSize(sourceDescriptor));
 	TupleDescCopy(truncdesc, sourceDescriptor);
 	truncdesc->natts = leavenatts;
 
diff --git a/src/backend/access/common/tupdesc.c b/src/backend/access/common/tupdesc.c
index b49584768e5..47379fef220 100644
--- a/src/backend/access/common/tupdesc.c
+++ b/src/backend/access/common/tupdesc.c
@@ -57,33 +57,6 @@ ResourceOwnerForgetTupleDesc(ResourceOwner owner, TupleDesc tupdesc)
 }
 
 /*
- * populate_compact_attribute
- *		Fills in the corresponding CompactAttribute element from the
- *		Form_pg_attribute for the given attribute number.  This must be called
- *		whenever a change is made to a Form_pg_attribute in the TupleDesc.
- */
-void
-populate_compact_attribute(TupleDesc tupdesc, int attnum)
-{
-	Form_pg_attribute src = TupleDescAttr(tupdesc, attnum);
-	CompactAttribute *dst = &tupdesc->compact_attrs[attnum];
-
-	memset(dst, 0, sizeof(CompactAttribute));
-
-	dst->attcacheoff = -1;
-	dst->attlen = src->attlen;
-
-	dst->attbyval = src->attbyval;
-	dst->attispackable = (src->attstorage != TYPSTORAGE_PLAIN);
-	dst->atthasmissing = src->atthasmissing;
-	dst->attisdropped = src->attisdropped;
-	dst->attgenerated = (src->attgenerated != '\0');
-	dst->attnotnull = src->attnotnull;
-
-	dst->attalign = src->attalign;
-}
-
-/*
  * CreateTemplateTupleDesc
  *		This function allocates an empty tuple descriptor structure.
  *
@@ -101,19 +74,18 @@ CreateTemplateTupleDesc(int natts)
 	Assert(natts >= 0);
 
 	/*
-	 * Allocate enough memory for the tuple descriptor, the CompactAttribute
-	 * array and also an array of the full FormData_pg_attribute data.
+	 * Allocate enough memory for the tuple descriptor, including the
+	 * attribute rows.
 	 *
-	 * Note: the 'attrs' array stride is sizeof(FormData_pg_attribute), since
-	 * we declare the array elements as FormData_pg_attribute for notational
-	 * convenience.  However, we only guarantee that the first
+	 * Note: the attribute array stride is sizeof(FormData_pg_attribute),
+	 * since we declare the array elements as FormData_pg_attribute for
+	 * notational convenience.  However, we only guarantee that the first
 	 * ATTRIBUTE_FIXED_PART_SIZE bytes of each entry are valid; most code that
 	 * copies tupdesc entries around copies just that much.  In principle that
 	 * could be less due to trailing padding, although with the current
 	 * definition of pg_attribute there probably isn't any padding.
 	 */
-	desc = (TupleDesc) palloc(offsetof(struct TupleDescData, compact_attrs) +
-							  natts * sizeof(CompactAttribute) +
+	desc = (TupleDesc) palloc(offsetof(struct TupleDescData, attrs) +
 							  natts * sizeof(FormData_pg_attribute));
 
 	/*
@@ -124,7 +96,6 @@ CreateTemplateTupleDesc(int natts)
 	desc->tdtypeid = RECORDOID;
 	desc->tdtypmod = -1;
 	desc->tdrefcount = -1;		/* assume not reference-counted */
-	desc->attrs = TupleDescAttrAddress(desc);
 
 	return desc;
 }
@@ -146,10 +117,8 @@ CreateTupleDesc(int natts, Form_pg_attribute *attrs)
 	desc = CreateTemplateTupleDesc(natts);
 
 	for (i = 0; i < natts; ++i)
-	{
 		memcpy(TupleDescAttr(desc, i), attrs[i], ATTRIBUTE_FIXED_PART_SIZE);
-		populate_compact_attribute(desc, i);
-	}
+
 	return desc;
 }
 
@@ -186,8 +155,6 @@ CreateTupleDescCopy(TupleDesc tupdesc)
 		att->atthasmissing = false;
 		att->attidentity = '\0';
 		att->attgenerated = '\0';
-
-		populate_compact_attribute(desc, i);
 	}
 
 	/* We can copy the tuple type identification, too */
@@ -216,9 +183,6 @@ CreateTupleDescCopyConstr(TupleDesc tupdesc)
 		   TupleDescAttr(tupdesc, 0),
 		   desc->natts * sizeof(FormData_pg_attribute));
 
-	for (i = 0; i < desc->natts; i++)
-		populate_compact_attribute(desc, i);
-
 	/* Copy the TupleConstr data structure, if any */
 	if (constr)
 	{
@@ -243,7 +207,7 @@ CreateTupleDescCopyConstr(TupleDesc tupdesc)
 			{
 				if (constr->missing[i].am_present)
 				{
-					CompactAttribute *attr = TupleDescCompactAttr(tupdesc, i);
+					Form_pg_attribute attr = TupleDescAttr(tupdesc, i);
 
 					cpy->missing[i].am_value = datumCopy(constr->missing[i].am_value,
 														 attr->attbyval,
@@ -288,16 +252,10 @@ TupleDescCopy(TupleDesc dst, TupleDesc src)
 {
 	int			i;
 
-	/* Flat-copy the header and attribute arrays */
+	/* Flat-copy the header and attribute array */
 	memcpy(dst, src, TupleDescSize(src));
 
 	/*
-	 * Adjust 'attrs' to point to the dst FormData_pg_attribute array rather
-	 * than the src's.
-	 */
-	dst->attrs = TupleDescAttrAddress(dst);
-
-	/*
 	 * Since we're not copying constraints and defaults, clear fields
 	 * associated with them.
 	 */
@@ -310,8 +268,6 @@ TupleDescCopy(TupleDesc dst, TupleDesc src)
 		att->atthasmissing = false;
 		att->attidentity = '\0';
 		att->attgenerated = '\0';
-
-		populate_compact_attribute(dst, i);
 	}
 	dst->constr = NULL;
 
@@ -366,8 +322,6 @@ TupleDescCopyEntry(TupleDesc dst, AttrNumber dstAttno,
 	dstAtt->atthasmissing = false;
 	dstAtt->attidentity = '\0';
 	dstAtt->attgenerated = '\0';
-
-	populate_compact_attribute(dst, dstAttno - 1);
 }
 
 /*
@@ -567,7 +521,7 @@ equalTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2)
 					return false;
 				if (missval1->am_present)
 				{
-					CompactAttribute *missatt1 = TupleDescCompactAttr(tupdesc1, i);
+					Form_pg_attribute missatt1 = TupleDescAttr(tupdesc1, i);
 
 					if (!datumIsEqual(missval1->am_value, missval2->am_value,
 									  missatt1->attbyval, missatt1->attlen))
@@ -760,8 +714,6 @@ TupleDescInitEntry(TupleDesc desc,
 	att->attcompression = InvalidCompressionMethod;
 	att->attcollation = typeForm->typcollation;
 
-	populate_compact_attribute(desc, attributeNumber - 1);
-
 	ReleaseSysCache(tuple);
 }
 
@@ -869,8 +821,6 @@ TupleDescInitBuiltinEntry(TupleDesc desc,
 		default:
 			elog(ERROR, "unsupported type %u", oidtypeid);
 	}
-
-	populate_compact_attribute(desc, attributeNumber - 1);
 }
 
 /*