Implement comparison of generic records (composite types), and invent a

pseudo-type record[] to represent arrays of possibly-anonymous composite
types.  Since composite datums carry their own type identification, no
extra knowledge is needed at the array level.

The main reason for doing this right now is that it is necessary to support
the general case of detection of cycles in recursive queries: if you need to
compare more than one column to detect a cycle, you need to compare a ROW()
to an array built from ROW()s, at least if you want to do it as the spec
suggests.  Add some documentation and regression tests concerning the cycle
detection issue.

doc/src/sgml/func.sgml

@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.448 2008/10/03 07:33:08 heikki Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.449 2008/10/13 16:25:19 tgl Exp $ -->
 
  <chapter id="functions">
   <title>Functions and Operators</title>
@@ -10667,6 +10667,20 @@ AND
    be either true or false, never null.
   </para>
 
+  <note>
+   <para>
+    The SQL specification requires row-wise comparison to return NULL if the
+    result depends on comparing two NULL values or a NULL and a non-NULL.
+    <productname>PostgreSQL</productname> does this only when comparing the
+    results of two row constructors or comparing a row constructor to the
+    output of a subquery (as in <xref linkend="functions-subquery">).
+    In other contexts where two composite-type values are compared, two
+    NULL field values are considered equal, and a NULL is considered larger
+    than a non-NULL.  This is necessary in order to have consistent sorting
+    and indexing behavior for composite types.
+   </para>
+  </note>
+
   </sect2>
  </sect1>
 

doc/src/sgml/queries.sgml

@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/queries.sgml,v 1.47 2008/10/07 19:27:03 tgl Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/queries.sgml,v 1.48 2008/10/13 16:25:19 tgl Exp $ -->
 
 <chapter id="queries">
  <title>Queries</title>
@@ -1604,8 +1604,85 @@ GROUP BY sub_part
    the recursive part of the query will eventually return no tuples,
    or else the query will loop indefinitely.  Sometimes, using
    <literal>UNION</> instead of <literal>UNION ALL</> can accomplish this
-   by discarding rows that duplicate previous output rows; this catches
-   cycles that would otherwise repeat.  A useful trick for testing queries
+   by discarding rows that duplicate previous output rows.  However, often a
+   cycle does not involve output rows that are completely duplicate: it may be
+   necessary to check just one or a few fields to see if the same point has
+   been reached before.  The standard method for handling such situations is
+   to compute an array of the already-visited values.  For example, consider
+   the following query that searches a table <structname>graph</> using a
+   <structfield>link</> field:
+
+<programlisting>
+WITH RECURSIVE search_graph(id, link, data, depth) AS (
+        SELECT g.id, g.link, g.data, 1
+        FROM graph g
+      UNION ALL
+        SELECT g.id, g.link, g.data, sg.depth + 1
+        FROM graph g, search_graph sg
+        WHERE g.id = sg.link
+)
+SELECT * FROM search_graph;
+</programlisting>
+
+   This query will loop if the <structfield>link</> relationships contain
+   cycles.  Because we require a <quote>depth</> output, just changing
+   <literal>UNION ALL</> to <literal>UNION</> would not eliminate the looping.
+   Instead we need to recognize whether we have reached the same row again
+   while following a particular path of links.  We add two columns
+   <structfield>path</> and <structfield>cycle</> to the loop-prone query:
+
+<programlisting>
+WITH RECURSIVE search_graph(id, link, data, depth, path, cycle) AS (
+        SELECT g.id, g.link, g.data, 1,
+          ARRAY[g.id],
+          false
+        FROM graph g
+      UNION ALL
+        SELECT g.id, g.link, g.data, sg.depth + 1,
+          path || ARRAY[g.id],
+          g.id = ANY(path)
+        FROM graph g, search_graph sg
+        WHERE g.id = sg.link AND NOT cycle
+)
+SELECT * FROM search_graph;
+</programlisting>
+
+   Aside from preventing cycles, the array value is often useful in its own
+   right as representing the <quote>path</> taken to reach any particular row.
+  </para>
+
+  <para>
+   In the general case where more than one field needs to be checked to
+   recognize a cycle, use an array of rows.  For example, if we needed to
+   compare fields <structfield>f1</> and <structfield>f2</>:
+
+<programlisting>
+WITH RECURSIVE search_graph(id, link, data, depth, path, cycle) AS (
+        SELECT g.id, g.link, g.data, 1,
+          ARRAY[ROW(g.f1, g.f2)],
+          false
+        FROM graph g
+      UNION ALL
+        SELECT g.id, g.link, g.data, sg.depth + 1,
+          path || ARRAY[ROW(g.f1, g.f2)],
+          ROW(g.f1, g.f2) = ANY(path)
+        FROM graph g, search_graph sg
+        WHERE g.id = sg.link AND NOT cycle
+)
+SELECT * FROM search_graph;
+</programlisting>
+  </para>
+
+  <tip>
+   <para>
+    Omit the <literal>ROW()</> syntax in the common case where only one field
+    needs to be checked to recognize a cycle.  This allows a simple array
+    rather than a composite-type array to be used, gaining efficiency.
+   </para>
+  </tip>
+
+  <para>
+   A helpful trick for testing queries
    when you are not certain if they might loop is to place a <literal>LIMIT</>
    in the parent query.  For example, this query would loop forever without
    the <literal>LIMIT</>:

src/backend/commands/indexcmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.179 2008/08/25 22:42:32 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.180 2008/10/13 16:25:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -795,7 +795,8 @@ ComputeIndexAttrs(IndexInfo *indexInfo,
 			atttype = attform->atttypid;
 			ReleaseSysCache(atttuple);
 		}
-		else if (attribute->expr && IsA(attribute->expr, Var))
+		else if (attribute->expr && IsA(attribute->expr, Var) &&
+				 ((Var *) attribute->expr)->varattno != InvalidAttrNumber)
 		{
 			/* Tricky tricky, he wrote (column) ... treat as simple attr */
 			Var		   *var = (Var *) attribute->expr;

src/backend/parser/parse_coerce.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.168 2008/10/06 17:39:26 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.169 2008/10/13 16:25:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -46,6 +46,7 @@ static Node *coerce_record_to_complex(ParseState *pstate, Node *node,
 						 CoercionContext ccontext,
 						 CoercionForm cformat,
 						 int location);
+static bool is_complex_array(Oid typid);
 
 
 /*
@@ -402,6 +403,21 @@ coerce_type(ParseState *pstate, Node *node,
 		/* NB: we do NOT want a RelabelType here */
 		return node;
 	}
+#ifdef NOT_USED
+	if (inputTypeId == RECORDARRAYOID &&
+		is_complex_array(targetTypeId))
+	{
+		/* Coerce record[] to a specific complex array type */
+		/* not implemented yet ... */
+	}
+#endif
+	if (targetTypeId == RECORDARRAYOID &&
+		is_complex_array(inputTypeId))
+	{
+		/* Coerce a specific complex array type to record[] */
+		/* NB: we do NOT want a RelabelType here */
+		return node;
+	}
 	if (typeInheritsFrom(inputTypeId, targetTypeId))
 	{
 		/*
@@ -492,6 +508,23 @@ can_coerce_type(int nargs, Oid *input_typeids, Oid *target_typeids,
 			ISCOMPLEX(inputTypeId))
 			continue;
 
+#ifdef NOT_USED					/* not implemented yet */
+		/*
+		 * If input is record[] and target is a composite array type,
+		 * assume we can coerce (may need tighter checking here)
+		 */
+		if (inputTypeId == RECORDARRAYOID &&
+			is_complex_array(targetTypeId))
+			continue;
+#endif
+
+		/*
+		 * If input is a composite array type and target is record[], accept
+		 */
+		if (targetTypeId == RECORDARRAYOID &&
+			is_complex_array(inputTypeId))
+			continue;
+
 		/*
 		 * If input is a class type that inherits from target, accept
 		 */
@@ -1724,8 +1757,8 @@ IsPreferredType(TYPCATEGORY category, Oid type)
  * invokable, no-function-needed pg_cast entry.  Also, a domain is always
  * binary-coercible to its base type, though *not* vice versa (in the other
  * direction, one must apply domain constraint checks before accepting the
- * value as legitimate).  We also need to special-case the polymorphic
- * ANYARRAY type.
+ * value as legitimate).  We also need to special-case various polymorphic
+ * types.
  *
  * This function replaces IsBinaryCompatible(), which was an inherently
  * symmetric test.	Since the pg_cast entries aren't necessarily symmetric,
@@ -1765,6 +1798,16 @@ IsBinaryCoercible(Oid srctype, Oid targettype)
 		if (type_is_enum(srctype))
 			return true;
 
+	/* Also accept any composite type as coercible to RECORD */
+	if (targettype == RECORDOID)
+		if (ISCOMPLEX(srctype))
+			return true;
+
+	/* Also accept any composite array type as coercible to RECORD[] */
+	if (targettype == RECORDARRAYOID)
+		if (is_complex_array(srctype))
+			return true;
+
 	/* Else look in pg_cast */
 	tuple = SearchSysCache(CASTSOURCETARGET,
 						   ObjectIdGetDatum(srctype),
@@ -2002,3 +2045,18 @@ find_typmod_coercion_function(Oid typeId,
 
 	return result;
 }
+
+/*
+ * is_complex_array
+ *		Is this type an array of composite?
+ *
+ * Note: this will not return true for record[]; check for RECORDARRAYOID
+ * separately if needed.
+ */
+static bool
+is_complex_array(Oid typid)
+{
+	Oid			elemtype = get_element_type(typid);
+
+	return (OidIsValid(elemtype) && ISCOMPLEX(elemtype));
+}

src/backend/utils/adt/rowtypes.c

@@ -1,14 +1,14 @@
 /*-------------------------------------------------------------------------
  *
  * rowtypes.c
- *	  I/O functions for generic composite types.
+ *	  I/O and comparison functions for generic composite types.
  *
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/rowtypes.c,v 1.21 2008/05/12 00:00:51 alvherre Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/rowtypes.c,v 1.22 2008/10/13 16:25:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -42,6 +42,24 @@ typedef struct RecordIOData
 	ColumnIOData columns[1];	/* VARIABLE LENGTH ARRAY */
 } RecordIOData;
 
+/*
+ * structure to cache metadata needed for record comparison
+ */
+typedef struct ColumnCompareData
+{
+	TypeCacheEntry *typentry;	/* has everything we need, actually */
+} ColumnCompareData;
+
+typedef struct RecordCompareData
+{
+	int			ncolumns;		/* allocated length of columns[] */
+	Oid			record1_type;
+	int32		record1_typmod;
+	Oid			record2_type;
+	int32		record2_typmod;
+	ColumnCompareData columns[1];	/* VARIABLE LENGTH ARRAY */
+} RecordCompareData;
+
 
 /*
  * record_in		- input routine for any composite type.
@@ -734,3 +752,479 @@ record_send(PG_FUNCTION_ARGS)
 
 	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
 }
+
+
+/*
+ * record_cmp()
+ * Internal comparison function for records.
+ *
+ * Returns -1, 0 or 1
+ *
+ * Do not assume that the two inputs are exactly the same record type;
+ * for instance we might be comparing an anonymous ROW() construct against a
+ * named composite type.  We will compare as long as they have the same number
+ * of non-dropped columns of the same types.
+ */
+static int
+record_cmp(FunctionCallInfo fcinfo)
+{
+	HeapTupleHeader record1 = PG_GETARG_HEAPTUPLEHEADER(0);
+	HeapTupleHeader record2 = PG_GETARG_HEAPTUPLEHEADER(1);
+	int			result = 0;
+	Oid			tupType1;
+	Oid			tupType2;
+	int32		tupTypmod1;
+	int32		tupTypmod2;
+	TupleDesc	tupdesc1;
+	TupleDesc	tupdesc2;
+	HeapTupleData tuple1;
+	HeapTupleData tuple2;
+	int			ncolumns1;
+	int			ncolumns2;
+	RecordCompareData *my_extra;
+	int			ncols;
+	Datum	   *values1;
+	Datum	   *values2;
+	bool	   *nulls1;
+	bool	   *nulls2;
+	int			i1;
+	int			i2;
+	int			j;
+
+	/* Extract type info from the tuples */
+	tupType1 = HeapTupleHeaderGetTypeId(record1);
+	tupTypmod1 = HeapTupleHeaderGetTypMod(record1);
+	tupdesc1 = lookup_rowtype_tupdesc(tupType1, tupTypmod1);
+	ncolumns1 = tupdesc1->natts;
+	tupType2 = HeapTupleHeaderGetTypeId(record2);
+	tupTypmod2 = HeapTupleHeaderGetTypMod(record2);
+	tupdesc2 = lookup_rowtype_tupdesc(tupType2, tupTypmod2);
+	ncolumns2 = tupdesc2->natts;
+
+	/* Build temporary HeapTuple control structures */
+	tuple1.t_len = HeapTupleHeaderGetDatumLength(record1);
+	ItemPointerSetInvalid(&(tuple1.t_self));
+	tuple1.t_tableOid = InvalidOid;
+	tuple1.t_data = record1;
+	tuple2.t_len = HeapTupleHeaderGetDatumLength(record2);
+	ItemPointerSetInvalid(&(tuple2.t_self));
+	tuple2.t_tableOid = InvalidOid;
+	tuple2.t_data = record2;
+
+	/*
+	 * We arrange to look up the needed comparison info just once per series
+	 * of calls, assuming the record types don't change underneath us.
+	 */
+	ncols = Max(ncolumns1, ncolumns2);
+	my_extra = (RecordCompareData *) fcinfo->flinfo->fn_extra;
+	if (my_extra == NULL ||
+		my_extra->ncolumns < ncols)
+	{
+		fcinfo->flinfo->fn_extra =
+			MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
+							   sizeof(RecordCompareData) - sizeof(ColumnCompareData)
+							   + ncols * sizeof(ColumnCompareData));
+		my_extra = (RecordCompareData *) fcinfo->flinfo->fn_extra;
+		my_extra->ncolumns = ncols;
+		my_extra->record1_type = InvalidOid;
+		my_extra->record1_typmod = 0;
+		my_extra->record2_type = InvalidOid;
+		my_extra->record2_typmod = 0;
+	}
+
+	if (my_extra->record1_type != tupType1 ||
+		my_extra->record1_typmod != tupTypmod1 ||
+		my_extra->record2_type != tupType2 ||
+		my_extra->record2_typmod != tupTypmod2)
+	{
+		MemSet(my_extra->columns, 0, ncols * sizeof(ColumnCompareData));
+		my_extra->record1_type = tupType1;
+		my_extra->record1_typmod = tupTypmod1;
+		my_extra->record2_type = tupType2;
+		my_extra->record2_typmod = tupTypmod2;
+	}
+
+	/* Break down the tuples into fields */
+	values1 = (Datum *) palloc(ncolumns1 * sizeof(Datum));
+	nulls1 = (bool *) palloc(ncolumns1 * sizeof(bool));
+	heap_deform_tuple(&tuple1, tupdesc1, values1, nulls1);
+	values2 = (Datum *) palloc(ncolumns2 * sizeof(Datum));
+	nulls2 = (bool *) palloc(ncolumns2 * sizeof(bool));
+	heap_deform_tuple(&tuple2, tupdesc2, values2, nulls2);
+
+	/*
+	 * Scan corresponding columns, allowing for dropped columns in different
+	 * places in the two rows.  i1 and i2 are physical column indexes,
+	 * j is the logical column index.
+	 */
+	i1 = i2 = j = 0;
+	while (i1 < ncolumns1 || i2 < ncolumns2)
+	{
+		TypeCacheEntry *typentry;
+		FunctionCallInfoData locfcinfo;
+		int32		cmpresult;
+
+		/*
+		 * Skip dropped columns
+		 */
+		if (i1 < ncolumns1 && tupdesc1->attrs[i1]->attisdropped)
+		{
+			i1++;
+			continue;
+		}
+		if (i2 < ncolumns2 && tupdesc2->attrs[i2]->attisdropped)
+		{
+			i2++;
+			continue;
+		}
+		if (i1 >= ncolumns1 || i2 >= ncolumns2)
+			break;				/* we'll deal with mismatch below loop */
+
+		/*
+		 * Have two matching columns, they must be same type
+		 */
+		if (tupdesc1->attrs[i1]->atttypid !=
+			tupdesc2->attrs[i2]->atttypid)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("cannot compare dissimilar column types %s and %s at record column %d",
+							format_type_be(tupdesc1->attrs[i1]->atttypid),
+							format_type_be(tupdesc2->attrs[i2]->atttypid),
+							j+1)));
+
+		/*
+		 * Lookup the comparison function if not done already
+		 */
+		typentry = my_extra->columns[j].typentry;
+		if (typentry == NULL ||
+			typentry->type_id != tupdesc1->attrs[i1]->atttypid)
+		{
+			typentry = lookup_type_cache(tupdesc1->attrs[i1]->atttypid,
+										 TYPECACHE_CMP_PROC_FINFO);
+			if (!OidIsValid(typentry->cmp_proc_finfo.fn_oid))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_FUNCTION),
+						 errmsg("could not identify a comparison function for type %s",
+								format_type_be(typentry->type_id))));
+			my_extra->columns[j].typentry = typentry;
+		}
+
+		/*
+		 * We consider two NULLs equal; NULL > not-NULL.
+		 */
+		if (!nulls1[i1] || !nulls2[i2])
+		{
+			if (nulls1[i1])
+			{
+				/* arg1 is greater than arg2 */
+				result = 1;
+				break;
+			}
+			if (nulls2[i2])
+			{
+				/* arg1 is less than arg2 */
+				result = -1;
+				break;
+			}
+
+			/* Compare the pair of elements */
+			InitFunctionCallInfoData(locfcinfo, &typentry->cmp_proc_finfo, 2,
+									 NULL, NULL);
+			locfcinfo.arg[0] = values1[i1];
+			locfcinfo.arg[1] = values2[i2];
+			locfcinfo.argnull[0] = false;
+			locfcinfo.argnull[1] = false;
+			locfcinfo.isnull = false;
+			cmpresult = DatumGetInt32(FunctionCallInvoke(&locfcinfo));
+
+			if (cmpresult < 0)
+			{
+				/* arg1 is less than arg2 */
+				result = -1;
+				break;
+			}
+			else if (cmpresult > 0)
+			{
+				/* arg1 is greater than arg2 */
+				result = 1;
+				break;
+			}
+		}
+
+		/* equal, so continue to next column */
+		i1++, i2++, j++;
+	}
+
+	/*
+	 * If we didn't break out of the loop early, check for column count
+	 * mismatch.  (We do not report such mismatch if we found unequal
+	 * column values; is that a feature or a bug?)
+	 */
+	if (result == 0)
+	{
+		if (i1 != ncolumns1 || i2 != ncolumns2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("cannot compare record types with different numbers of columns")));
+	}
+
+	pfree(values1);
+	pfree(nulls1);
+	pfree(values2);
+	pfree(nulls2);
+	ReleaseTupleDesc(tupdesc1);
+	ReleaseTupleDesc(tupdesc2);
+
+	/* Avoid leaking memory when handed toasted input. */
+	PG_FREE_IF_COPY(record1, 0);
+	PG_FREE_IF_COPY(record2, 1);
+
+	return result;
+}
+
+/*
+ * record_eq :
+ *		  compares two records for equality
+ * result :
+ *		  returns true if the records are equal, false otherwise.
+ *
+ * Note: we do not use record_cmp here, since equality may be meaningful in
+ * datatypes that don't have a total ordering (and hence no btree support).
+ */
+Datum
+record_eq(PG_FUNCTION_ARGS)
+{
+	HeapTupleHeader record1 = PG_GETARG_HEAPTUPLEHEADER(0);
+	HeapTupleHeader record2 = PG_GETARG_HEAPTUPLEHEADER(1);
+	bool		result = true;
+	Oid			tupType1;
+	Oid			tupType2;
+	int32		tupTypmod1;
+	int32		tupTypmod2;
+	TupleDesc	tupdesc1;
+	TupleDesc	tupdesc2;
+	HeapTupleData tuple1;
+	HeapTupleData tuple2;
+	int			ncolumns1;
+	int			ncolumns2;
+	RecordCompareData *my_extra;
+	int			ncols;
+	Datum	   *values1;
+	Datum	   *values2;
+	bool	   *nulls1;
+	bool	   *nulls2;
+	int			i1;
+	int			i2;
+	int			j;
+
+	/* Extract type info from the tuples */
+	tupType1 = HeapTupleHeaderGetTypeId(record1);
+	tupTypmod1 = HeapTupleHeaderGetTypMod(record1);
+	tupdesc1 = lookup_rowtype_tupdesc(tupType1, tupTypmod1);
+	ncolumns1 = tupdesc1->natts;
+	tupType2 = HeapTupleHeaderGetTypeId(record2);
+	tupTypmod2 = HeapTupleHeaderGetTypMod(record2);
+	tupdesc2 = lookup_rowtype_tupdesc(tupType2, tupTypmod2);
+	ncolumns2 = tupdesc2->natts;
+
+	/* Build temporary HeapTuple control structures */
+	tuple1.t_len = HeapTupleHeaderGetDatumLength(record1);
+	ItemPointerSetInvalid(&(tuple1.t_self));
+	tuple1.t_tableOid = InvalidOid;
+	tuple1.t_data = record1;
+	tuple2.t_len = HeapTupleHeaderGetDatumLength(record2);
+	ItemPointerSetInvalid(&(tuple2.t_self));
+	tuple2.t_tableOid = InvalidOid;
+	tuple2.t_data = record2;
+
+	/*
+	 * We arrange to look up the needed comparison info just once per series
+	 * of calls, assuming the record types don't change underneath us.
+	 */
+	ncols = Max(ncolumns1, ncolumns2);
+	my_extra = (RecordCompareData *) fcinfo->flinfo->fn_extra;
+	if (my_extra == NULL ||
+		my_extra->ncolumns < ncols)
+	{
+		fcinfo->flinfo->fn_extra =
+			MemoryContextAlloc(fcinfo->flinfo->fn_mcxt,
+							   sizeof(RecordCompareData) - sizeof(ColumnCompareData)
+							   + ncols * sizeof(ColumnCompareData));
+		my_extra = (RecordCompareData *) fcinfo->flinfo->fn_extra;
+		my_extra->ncolumns = ncols;
+		my_extra->record1_type = InvalidOid;
+		my_extra->record1_typmod = 0;
+		my_extra->record2_type = InvalidOid;
+		my_extra->record2_typmod = 0;
+	}
+
+	if (my_extra->record1_type != tupType1 ||
+		my_extra->record1_typmod != tupTypmod1 ||
+		my_extra->record2_type != tupType2 ||
+		my_extra->record2_typmod != tupTypmod2)
+	{
+		MemSet(my_extra->columns, 0, ncols * sizeof(ColumnCompareData));
+		my_extra->record1_type = tupType1;
+		my_extra->record1_typmod = tupTypmod1;
+		my_extra->record2_type = tupType2;
+		my_extra->record2_typmod = tupTypmod2;
+	}
+
+	/* Break down the tuples into fields */
+	values1 = (Datum *) palloc(ncolumns1 * sizeof(Datum));
+	nulls1 = (bool *) palloc(ncolumns1 * sizeof(bool));
+	heap_deform_tuple(&tuple1, tupdesc1, values1, nulls1);
+	values2 = (Datum *) palloc(ncolumns2 * sizeof(Datum));
+	nulls2 = (bool *) palloc(ncolumns2 * sizeof(bool));
+	heap_deform_tuple(&tuple2, tupdesc2, values2, nulls2);
+
+	/*
+	 * Scan corresponding columns, allowing for dropped columns in different
+	 * places in the two rows.  i1 and i2 are physical column indexes,
+	 * j is the logical column index.
+	 */
+	i1 = i2 = j = 0;
+	while (i1 < ncolumns1 || i2 < ncolumns2)
+	{
+		TypeCacheEntry *typentry;
+		FunctionCallInfoData locfcinfo;
+		bool		oprresult;
+
+		/*
+		 * Skip dropped columns
+		 */
+		if (i1 < ncolumns1 && tupdesc1->attrs[i1]->attisdropped)
+		{
+			i1++;
+			continue;
+		}
+		if (i2 < ncolumns2 && tupdesc2->attrs[i2]->attisdropped)
+		{
+			i2++;
+			continue;
+		}
+		if (i1 >= ncolumns1 || i2 >= ncolumns2)
+			break;				/* we'll deal with mismatch below loop */
+
+		/*
+		 * Have two matching columns, they must be same type
+		 */
+		if (tupdesc1->attrs[i1]->atttypid !=
+			tupdesc2->attrs[i2]->atttypid)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("cannot compare dissimilar column types %s and %s at record column %d",
+							format_type_be(tupdesc1->attrs[i1]->atttypid),
+							format_type_be(tupdesc2->attrs[i2]->atttypid),
+							j+1)));
+
+		/*
+		 * Lookup the equality function if not done already
+		 */
+		typentry = my_extra->columns[j].typentry;
+		if (typentry == NULL ||
+			typentry->type_id != tupdesc1->attrs[i1]->atttypid)
+		{
+			typentry = lookup_type_cache(tupdesc1->attrs[i1]->atttypid,
+										 TYPECACHE_EQ_OPR_FINFO);
+			if (!OidIsValid(typentry->eq_opr_finfo.fn_oid))
+				ereport(ERROR,
+						(errcode(ERRCODE_UNDEFINED_FUNCTION),
+						 errmsg("could not identify an equality operator for type %s",
+								format_type_be(typentry->type_id))));
+			my_extra->columns[j].typentry = typentry;
+		}
+
+		/*
+		 * We consider two NULLs equal; NULL > not-NULL.
+		 */
+		if (!nulls1[i1] || !nulls2[i2])
+		{
+			if (nulls1[i1] || nulls2[i2])
+			{
+				result = false;
+				break;
+			}
+
+			/* Compare the pair of elements */
+			InitFunctionCallInfoData(locfcinfo, &typentry->eq_opr_finfo, 2,
+									 NULL, NULL);
+			locfcinfo.arg[0] = values1[i1];
+			locfcinfo.arg[1] = values2[i2];
+			locfcinfo.argnull[0] = false;
+			locfcinfo.argnull[1] = false;
+			locfcinfo.isnull = false;
+			oprresult = DatumGetBool(FunctionCallInvoke(&locfcinfo));
+			if (!oprresult)
+			{
+				result = false;
+				break;
+			}
+		}
+
+		/* equal, so continue to next column */
+		i1++, i2++, j++;
+	}
+
+	/*
+	 * If we didn't break out of the loop early, check for column count
+	 * mismatch.  (We do not report such mismatch if we found unequal
+	 * column values; is that a feature or a bug?)
+	 */
+	if (result)
+	{
+		if (i1 != ncolumns1 || i2 != ncolumns2)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("cannot compare record types with different numbers of columns")));
+	}
+
+	pfree(values1);
+	pfree(nulls1);
+	pfree(values2);
+	pfree(nulls2);
+	ReleaseTupleDesc(tupdesc1);
+	ReleaseTupleDesc(tupdesc2);
+
+	/* Avoid leaking memory when handed toasted input. */
+	PG_FREE_IF_COPY(record1, 0);
+	PG_FREE_IF_COPY(record2, 1);
+
+	PG_RETURN_BOOL(result);
+}
+
+Datum
+record_ne(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_BOOL(!DatumGetBool(record_eq(fcinfo)));
+}
+
+Datum
+record_lt(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_BOOL(record_cmp(fcinfo) < 0);
+}
+
+Datum
+record_gt(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_BOOL(record_cmp(fcinfo) > 0);
+}
+
+Datum
+record_le(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_BOOL(record_cmp(fcinfo) <= 0);
+}
+
+Datum
+record_ge(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_BOOL(record_cmp(fcinfo) >= 0);
+}
+
+Datum
+btrecordcmp(PG_FUNCTION_ARGS)
+{
+	PG_RETURN_INT32(record_cmp(fcinfo));
+}

src/include/catalog/catversion.h

@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.496 2008/10/06 17:39:26 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.497 2008/10/13 16:25:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200810063
+#define CATALOG_VERSION_NO	200810131
 
 #endif

src/include/catalog/pg_amop.h

@@ -29,7 +29,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_amop.h,v 1.87 2008/05/27 00:13:09 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_amop.h,v 1.88 2008/10/13 16:25:19 tgl Exp $
  *
  * NOTES
  *	 the genbki.sh script reads this file and generates .bki
@@ -470,6 +470,16 @@ DATA(insert (	397   2277 2277 3 1070	403 ));
 DATA(insert (	397   2277 2277 4 1075	403 ));
 DATA(insert (	397   2277 2277 5 1073	403 ));
 
+/*
+ *	btree record_ops
+ */
+
+DATA(insert (	2994  2249 2249 1 2990	403 ));
+DATA(insert (	2994  2249 2249 2 2992	403 ));
+DATA(insert (	2994  2249 2249 3 2988	403 ));
+DATA(insert (	2994  2249 2249 4 2993	403 ));
+DATA(insert (	2994  2249 2249 5 2991	403 ));
+
 /*
  * btree uuid_ops
  */

src/include/catalog/pg_amproc.h

@@ -22,7 +22,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_amproc.h,v 1.73 2008/05/27 00:13:09 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_amproc.h,v 1.74 2008/10/13 16:25:19 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -111,6 +111,7 @@ DATA(insert (	1986   19 19 1 359 ));
 DATA(insert (	1988   1700 1700 1 1769 ));
 DATA(insert (	1989   26 26 1 356 ));
 DATA(insert (	1991   30 30 1 404 ));
+DATA(insert (	2994   2249 2249 1 2987 ));
 DATA(insert (	1994   25 25 1 360 ));
 DATA(insert (	1996   1083 1083 1 1107 ));
 DATA(insert (	2000   1266 1266 1 1358 ));

src/include/catalog/pg_opclass.h

@@ -28,7 +28,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_opclass.h,v 1.83 2008/09/15 18:43:41 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_opclass.h,v 1.84 2008/10/13 16:25:20 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -137,6 +137,7 @@ DATA(insert OID = 1981 ( 403	oid_ops		PGNSP PGUID 1989   26 t 0 ));
 DATA(insert (	405		oid_ops				PGNSP PGUID 1990   26 t 0 ));
 DATA(insert (	403		oidvector_ops		PGNSP PGUID 1991   30 t 0 ));
 DATA(insert (	405		oidvector_ops		PGNSP PGUID 1992   30 t 0 ));
+DATA(insert (	403		record_ops			PGNSP PGUID 2994 2249 t 0 ));
 DATA(insert (	403		text_ops			PGNSP PGUID 1994   25 t 0 ));
 DATA(insert (	405		text_ops			PGNSP PGUID 1995   25 t 0 ));
 DATA(insert (	403		time_ops			PGNSP PGUID 1996 1083 t 0 ));

src/include/catalog/pg_operator.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_operator.h,v 1.163 2008/09/19 19:03:40 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_operator.h,v 1.164 2008/10/13 16:25:20 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -933,6 +933,14 @@ DATA(insert OID = 3694 (  "<@"	   PGNSP PGUID b f f 3615	 3615	 16 3693	0	 tsq_m
 DATA(insert OID = 3762 (  "@@"	   PGNSP PGUID b f f 25		 25		 16    0	0	 ts_match_tt	contsel    contjoinsel	 ));
 DATA(insert OID = 3763 (  "@@"	   PGNSP PGUID b f f 25		 3615	 16    0	0	 ts_match_tq	contsel    contjoinsel	 ));
 
+/* generic record comparison operators */
+DATA(insert OID = 2988 (  "="	   PGNSP PGUID b t f 2249 2249 16 2988 2989 record_eq eqsel eqjoinsel ));
+DATA(insert OID = 2989 (  "<>"	   PGNSP PGUID b f f 2249 2249 16 2989 2988 record_ne neqsel neqjoinsel ));
+DATA(insert OID = 2990 (  "<"	   PGNSP PGUID b f f 2249 2249 16 2991 2993 record_lt scalarltsel scalarltjoinsel ));
+DATA(insert OID = 2991 (  ">"	   PGNSP PGUID b f f 2249 2249 16 2990 2992 record_gt scalargtsel scalargtjoinsel ));
+DATA(insert OID = 2992 (  "<="	   PGNSP PGUID b f f 2249 2249 16 2993 2991 record_le scalarltsel scalarltjoinsel ));
+DATA(insert OID = 2993 (  ">="	   PGNSP PGUID b f f 2249 2249 16 2992 2990 record_ge scalargtsel scalargtjoinsel ));
+
 
 /*
  * function prototypes

src/include/catalog/pg_opfamily.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_opfamily.h,v 1.9 2008/05/27 00:13:09 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_opfamily.h,v 1.10 2008/10/13 16:25:20 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -94,6 +94,7 @@ DATA(insert OID = 1989 (	403		oid_ops			PGNSP PGUID ));
 DATA(insert OID = 1990 (	405		oid_ops			PGNSP PGUID ));
 DATA(insert OID = 1991 (	403		oidvector_ops	PGNSP PGUID ));
 DATA(insert OID = 1992 (	405		oidvector_ops	PGNSP PGUID ));
+DATA(insert OID = 2994 (	403		record_ops		PGNSP PGUID ));
 DATA(insert OID = 1994 (	403		text_ops		PGNSP PGUID ));
 #define TEXT_BTREE_FAM_OID 1994
 DATA(insert OID = 1995 (	405		text_ops		PGNSP PGUID ));

src/include/catalog/pg_proc.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.518 2008/10/06 13:05:37 mha Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.519 2008/10/13 16:25:20 tgl Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -4560,6 +4560,22 @@ DESCR("get set of in-progress txids in snapshot");
 DATA(insert OID = 2948 (  txid_visible_in_snapshot	PGNSP PGUID 12 1  0 0 f f t f i 2 16 "20 2970" _null_ _null_ _null_ txid_visible_in_snapshot _null_ _null_ _null_ ));
 DESCR("is txid visible in snapshot?");
 
+/* record comparison */
+DATA(insert OID = 2981 (  record_eq		   PGNSP PGUID 12 1 0 0 f f t f i 2 16 "2249 2249" _null_ _null_ _null_ record_eq _null_ _null_ _null_ ));
+DESCR("record equal");
+DATA(insert OID = 2982 (  record_ne		   PGNSP PGUID 12 1 0 0 f f t f i 2 16 "2249 2249" _null_ _null_ _null_ record_ne _null_ _null_ _null_ ));
+DESCR("record not equal");
+DATA(insert OID = 2983 (  record_lt		   PGNSP PGUID 12 1 0 0 f f t f i 2 16 "2249 2249" _null_ _null_ _null_ record_lt _null_ _null_ _null_ ));
+DESCR("record less than");
+DATA(insert OID = 2984 (  record_gt		   PGNSP PGUID 12 1 0 0 f f t f i 2 16 "2249 2249" _null_ _null_ _null_ record_gt _null_ _null_ _null_ ));
+DESCR("record greater than");
+DATA(insert OID = 2985 (  record_le		   PGNSP PGUID 12 1 0 0 f f t f i 2 16 "2249 2249" _null_ _null_ _null_ record_le _null_ _null_ _null_ ));
+DESCR("record less than or equal");
+DATA(insert OID = 2986 (  record_ge		   PGNSP PGUID 12 1 0 0 f f t f i 2 16 "2249 2249" _null_ _null_ _null_ record_ge _null_ _null_ _null_ ));
+DESCR("record greater than or equal");
+DATA(insert OID = 2987 (  btrecordcmp	   PGNSP PGUID 12 1 0 0 f f t f i 2 23 "2249 2249" _null_ _null_ _null_ btrecordcmp _null_ _null_ _null_ ));
+DESCR("btree less-equal-greater");
+
 
 /*
  * Symbolic values for provolatile column: these indicate whether the result

src/include/catalog/pg_type.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_type.h,v 1.200 2008/09/25 03:28:56 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_type.h,v 1.201 2008/10/13 16:25:20 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -597,8 +597,10 @@ DATA(insert OID = 2949 ( _txid_snapshot PGNSP PGUID -1 f b A f t \054 0 2970 0 a
  * but there is now support for it in records and arrays.  Perhaps we should
  * just treat it as a regular base type?
  */
-DATA(insert OID = 2249 ( record			PGNSP PGUID -1 f p P f t \054 0 0 0 record_in record_out record_recv record_send - - - d x f 0 -1 0 _null_ _null_ ));
+DATA(insert OID = 2249 ( record			PGNSP PGUID -1 f p P f t \054 0 0 2287 record_in record_out record_recv record_send - - - d x f 0 -1 0 _null_ _null_ ));
 #define RECORDOID		2249
+DATA(insert OID = 2287 ( _record		PGNSP PGUID -1 f p P f t \054 0 2249 0 array_in array_out array_recv array_send - - - d x f 0 -1 0 _null_ _null_ ));
+#define RECORDARRAYOID	2287
 DATA(insert OID = 2275 ( cstring		PGNSP PGUID -2 f p P f t \054 0 0 1263 cstring_in cstring_out cstring_recv cstring_send - - - c p f 0 -1 0 _null_ _null_ ));
 #define CSTRINGOID		2275
 DATA(insert OID = 2276 ( any			PGNSP PGUID  4 t p P f t \054 0 0 0 any_in any_out - - - - - i p f 0 -1 0 _null_ _null_ ));

src/include/utils/builtins.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.323 2008/10/06 20:29:38 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/builtins.h,v 1.324 2008/10/13 16:25:20 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -524,6 +524,13 @@ extern Datum record_in(PG_FUNCTION_ARGS);
 extern Datum record_out(PG_FUNCTION_ARGS);
 extern Datum record_recv(PG_FUNCTION_ARGS);
 extern Datum record_send(PG_FUNCTION_ARGS);
+extern Datum record_eq(PG_FUNCTION_ARGS);
+extern Datum record_ne(PG_FUNCTION_ARGS);
+extern Datum record_lt(PG_FUNCTION_ARGS);
+extern Datum record_gt(PG_FUNCTION_ARGS);
+extern Datum record_le(PG_FUNCTION_ARGS);
+extern Datum record_ge(PG_FUNCTION_ARGS);
+extern Datum btrecordcmp(PG_FUNCTION_ARGS);
 
 /* ruleutils.c */
 extern Datum pg_get_ruledef(PG_FUNCTION_ARGS);

src/test/regress/expected/rowtypes.out

@@ -269,3 +269,23 @@ select ROW() = ROW();
 ERROR:  cannot compare rows of zero length
 LINE 1: select ROW() = ROW();
                      ^
+-- Check ability to create arrays of anonymous rowtypes
+select array[ row(1,2), row(3,4), row(5,6) ];
+           array           
+---------------------------
+ {"(1,2)","(3,4)","(5,6)"}
+(1 row)
+
+-- Check ability to compare an anonymous row to elements of an array
+select row(1,1.1) = any (array[ row(7,7.7), row(1,1.1), row(0,0.0) ]);
+ ?column? 
+----------
+ t
+(1 row)
+
+select row(1,1.1) = any (array[ row(7,7.7), row(1,1.0), row(0,0.0) ]);
+ ?column? 
+----------
+ f
+(1 row)
+

src/test/regress/expected/with.out

@@ -451,6 +451,54 @@ SELECT t1.id, count(t2.*) FROM t AS t1 JOIN t AS t2 ON
   3 |     7
 (2 rows)
 
+--
+-- test cycle detection
+--
+create temp table graph( f int, t int, label text );
+insert into graph values
+	(1, 2, 'arc 1 -> 2'),
+	(1, 3, 'arc 1 -> 3'),
+	(2, 3, 'arc 2 -> 3'),
+	(1, 4, 'arc 1 -> 4'),
+	(4, 5, 'arc 4 -> 5'),
+	(5, 1, 'arc 5 -> 1');
+with recursive search_graph(f, t, label, path, cycle) as (
+	select *, array[row(g.f, g.t)], false from graph g
+	union all
+	select g.*, path || array[row(g.f, g.t)], row(g.f, g.t) = any(path)
+	from graph g, search_graph sg
+	where g.f = sg.t and not cycle
+)
+select * from search_graph;
+ f | t |   label    |                   path                    | cycle 
+---+---+------------+-------------------------------------------+-------
+ 1 | 2 | arc 1 -> 2 | {"(1,2)"}                                 | f
+ 1 | 3 | arc 1 -> 3 | {"(1,3)"}                                 | f
+ 2 | 3 | arc 2 -> 3 | {"(2,3)"}                                 | f
+ 1 | 4 | arc 1 -> 4 | {"(1,4)"}                                 | f
+ 4 | 5 | arc 4 -> 5 | {"(4,5)"}                                 | f
+ 5 | 1 | arc 5 -> 1 | {"(5,1)"}                                 | f
+ 1 | 2 | arc 1 -> 2 | {"(5,1)","(1,2)"}                         | f
+ 1 | 3 | arc 1 -> 3 | {"(5,1)","(1,3)"}                         | f
+ 1 | 4 | arc 1 -> 4 | {"(5,1)","(1,4)"}                         | f
+ 2 | 3 | arc 2 -> 3 | {"(1,2)","(2,3)"}                         | f
+ 4 | 5 | arc 4 -> 5 | {"(1,4)","(4,5)"}                         | f
+ 5 | 1 | arc 5 -> 1 | {"(4,5)","(5,1)"}                         | f
+ 1 | 2 | arc 1 -> 2 | {"(4,5)","(5,1)","(1,2)"}                 | f
+ 1 | 3 | arc 1 -> 3 | {"(4,5)","(5,1)","(1,3)"}                 | f
+ 1 | 4 | arc 1 -> 4 | {"(4,5)","(5,1)","(1,4)"}                 | f
+ 2 | 3 | arc 2 -> 3 | {"(5,1)","(1,2)","(2,3)"}                 | f
+ 4 | 5 | arc 4 -> 5 | {"(5,1)","(1,4)","(4,5)"}                 | f
+ 5 | 1 | arc 5 -> 1 | {"(1,4)","(4,5)","(5,1)"}                 | f
+ 1 | 2 | arc 1 -> 2 | {"(1,4)","(4,5)","(5,1)","(1,2)"}         | f
+ 1 | 3 | arc 1 -> 3 | {"(1,4)","(4,5)","(5,1)","(1,3)"}         | f
+ 1 | 4 | arc 1 -> 4 | {"(1,4)","(4,5)","(5,1)","(1,4)"}         | t
+ 2 | 3 | arc 2 -> 3 | {"(4,5)","(5,1)","(1,2)","(2,3)"}         | f
+ 4 | 5 | arc 4 -> 5 | {"(4,5)","(5,1)","(1,4)","(4,5)"}         | t
+ 5 | 1 | arc 5 -> 1 | {"(5,1)","(1,4)","(4,5)","(5,1)"}         | t
+ 2 | 3 | arc 2 -> 3 | {"(1,4)","(4,5)","(5,1)","(1,2)","(2,3)"} | f
+(25 rows)
+
 --
 -- test multiple WITH queries
 --

src/test/regress/sql/rowtypes.sql

@@ -113,3 +113,10 @@ order by thousand, tenthous;
 select ROW();
 select ROW() IS NULL;
 select ROW() = ROW();
+
+-- Check ability to create arrays of anonymous rowtypes
+select array[ row(1,2), row(3,4), row(5,6) ];
+
+-- Check ability to compare an anonymous row to elements of an array
+select row(1,1.1) = any (array[ row(7,7.7), row(1,1.1), row(0,0.0) ]);
+select row(1,1.1) = any (array[ row(7,7.7), row(1,1.0), row(0,0.0) ]);

src/test/regress/sql/with.sql

@@ -250,6 +250,28 @@ SELECT t1.id, count(t2.*) FROM t AS t1 JOIN t AS t2 ON
 	GROUP BY t1.id
 	ORDER BY t1.id;
 
+--
+-- test cycle detection
+--
+create temp table graph( f int, t int, label text );
+
+insert into graph values
+	(1, 2, 'arc 1 -> 2'),
+	(1, 3, 'arc 1 -> 3'),
+	(2, 3, 'arc 2 -> 3'),
+	(1, 4, 'arc 1 -> 4'),
+	(4, 5, 'arc 4 -> 5'),
+	(5, 1, 'arc 5 -> 1');
+
+with recursive search_graph(f, t, label, path, cycle) as (
+	select *, array[row(g.f, g.t)], false from graph g
+	union all
+	select g.*, path || array[row(g.f, g.t)], row(g.f, g.t) = any(path)
+	from graph g, search_graph sg
+	where g.f = sg.t and not cycle
+)
+select * from search_graph;
+
 --
 -- test multiple WITH queries
 --