Index: doc/src/sgml/ref/create_domain.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/ref/create_domain.sgml,v
retrieving revision 1.32
diff -u -3 -p -r1.32 create_domain.sgml
--- doc/src/sgml/ref/create_domain.sgml	14 Nov 2008 10:22:46 -0000	1.32
+++ doc/src/sgml/ref/create_domain.sgml	25 Nov 2008 10:13:18 -0000
@@ -58,6 +58,12 @@ where <replaceable class="PARAMETER">con
    Define a domain rather than setting up each table's constraint
    individually.
   </para>
+
+  <para>
+   Domains are similar to distinct types, described in <xref
+   linkend="sql-createtype">, except that you can specify defaults or
+   constraints, and a domain can be implicitly cast to its base type.
+  </para>
  </refsect1>
 
  <refsect1>
Index: doc/src/sgml/ref/create_type.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/ref/create_type.sgml,v
retrieving revision 1.78
diff -u -3 -p -r1.78 create_type.sgml
--- doc/src/sgml/ref/create_type.sgml	14 Nov 2008 10:22:46 -0000	1.78
+++ doc/src/sgml/ref/create_type.sgml	25 Nov 2008 10:13:18 -0000
@@ -27,6 +27,8 @@ CREATE TYPE <replaceable class="paramete
 CREATE TYPE <replaceable class="parameter">name</replaceable> AS ENUM
     ( '<replaceable class="parameter">label</replaceable>' [, ... ] )
 
+CREATE TYPE <replaceable class="parameter">name</replaceable> AS <replaceable class="parameter">data_type</replaceable>
+
 CREATE TYPE <replaceable class="parameter">name</replaceable> (
     INPUT = <replaceable class="parameter">input_function</replaceable>,
     OUTPUT = <replaceable class="parameter">output_function</replaceable>
@@ -96,10 +98,25 @@ CREATE TYPE <replaceable class="paramete
   </refsect2>
 
   <refsect2>
+   <title>Distinct Types</title>
+
+   <para>
+    The third form of <command>CREATE TYPE</command> creates a
+    distinct type. Distinct types are similar to domains, as described
+    in <xref linkend="sql-createdomain">, except that they do not have
+    defaults or constraints, and they cannot be implicitly cast to
+    their base type. Distinct types are useful to avoid making
+    mistakes by comparing two unrelated values that happen to be the
+    same type, such as two integers representing supplier number and
+    part number.
+   </para>
+  </refsect2>
+
+  <refsect2>
    <title>Base Types</title>
 
   <para>
-   The third form of <command>CREATE TYPE</command> creates a new base type
+   The fourth form of <command>CREATE TYPE</command> creates a new base type
    (scalar type).  To create a new base type, you must be a superuser.
    (This restriction is made because an erroneous type definition could
    confuse or even crash the server.)
Index: src/backend/commands/typecmds.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/commands/typecmds.c,v
retrieving revision 1.126
diff -u -3 -p -r1.126 typecmds.c
--- src/backend/commands/typecmds.c	2 Nov 2008 01:45:28 -0000	1.126
+++ src/backend/commands/typecmds.c	25 Nov 2008 10:13:18 -0000
@@ -648,7 +648,7 @@ RemoveTypeById(Oid typeOid)
 
 /*
  * DefineDomain
- *		Registers a new domain.
+ *		Registers a new domain or distinct type.
  */
 void
 DefineDomain(CreateDomainStmt *stmt)
@@ -721,18 +721,27 @@ DefineDomain(CreateDomainStmt *stmt)
 	basetypeoid = HeapTupleGetOid(typeTup);
 
 	/*
-	 * Base type must be a plain base type, another domain or an enum. Domains
+	 * Base type must be a plain base type, another domain, distinct type, or an enum. Domains
 	 * over pseudotypes would create a security hole.  Domains over composite
 	 * types might be made to work in the future, but not today.
 	 */
 	typtype = baseType->typtype;
 	if (typtype != TYPTYPE_BASE &&
 		typtype != TYPTYPE_DOMAIN &&
+		typtype != TYPTYPE_DISTINCT &&
 		typtype != TYPTYPE_ENUM)
-		ereport(ERROR,
-				(errcode(ERRCODE_DATATYPE_MISMATCH),
-				 errmsg("\"%s\" is not a valid base type for a domain",
-						TypeNameToString(stmt->typename))));
+	{
+		if (stmt->distinct_type)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("\"%s\" is not a valid base type for a distinct type",
+							TypeNameToString(stmt->typename))));
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("\"%s\" is not a valid base type for a domain",
+							TypeNameToString(stmt->typename))));
+	}
 
 	/* passed by value */
 	byValue = baseType->typbyval;
@@ -938,7 +947,7 @@ DefineDomain(CreateDomainStmt *stmt)
 				   InvalidOid,	/* relation oid (n/a here) */
 				   0,			/* relation kind (ditto) */
 				   internalLength,		/* internal size */
-				   TYPTYPE_DOMAIN,		/* type-type (domain type) */
+				   stmt->distinct_type ? TYPTYPE_DISTINCT : TYPTYPE_DOMAIN,		/* type-type (distinct type or domain) */
 				   category,	/* type-category */
 				   false,		/* domain types are never preferred */
 				   delimiter,	/* array element delimiter */
Index: src/backend/executor/functions.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/executor/functions.c,v
retrieving revision 1.128
diff -u -3 -p -r1.128 functions.c
--- src/backend/executor/functions.c	31 Oct 2008 21:07:55 -0000	1.128
+++ src/backend/executor/functions.c	25 Nov 2008 10:13:18 -0000
@@ -1092,6 +1092,7 @@ check_sql_fn_retval(Oid func_id, Oid ret
 	fn_typtype = get_typtype(rettype);
 
 	if (fn_typtype == TYPTYPE_BASE ||
+		fn_typtype == TYPTYPE_DISTINCT ||
 		fn_typtype == TYPTYPE_DOMAIN ||
 		fn_typtype == TYPTYPE_ENUM ||
 		rettype == VOIDOID)
Index: src/backend/nodes/copyfuncs.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v
retrieving revision 1.413
diff -u -3 -p -r1.413 copyfuncs.c
--- src/backend/nodes/copyfuncs.c	24 Nov 2008 08:46:03 -0000	1.413
+++ src/backend/nodes/copyfuncs.c	25 Nov 2008 10:13:18 -0000
@@ -2659,6 +2659,7 @@ _copyCreateDomainStmt(CreateDomainStmt *
 	COPY_NODE_FIELD(domainname);
 	COPY_NODE_FIELD(typename);
 	COPY_NODE_FIELD(constraints);
+	COPY_SCALAR_FIELD(distinct_type);
 
 	return newnode;
 }
Index: src/backend/nodes/equalfuncs.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v
retrieving revision 1.338
diff -u -3 -p -r1.338 equalfuncs.c
--- src/backend/nodes/equalfuncs.c	24 Nov 2008 08:46:03 -0000	1.338
+++ src/backend/nodes/equalfuncs.c	25 Nov 2008 10:13:18 -0000
@@ -1342,6 +1342,7 @@ _equalCreateDomainStmt(CreateDomainStmt 
 	COMPARE_NODE_FIELD(domainname);
 	COMPARE_NODE_FIELD(typename);
 	COMPARE_NODE_FIELD(constraints);
+	COMPARE_SCALAR_FIELD(distinct_type);
 
 	return true;
 }
Index: src/backend/parser/gram.y
===================================================================
RCS file: /cvsroot/pgsql/src/backend/parser/gram.y,v
retrieving revision 2.640
diff -u -3 -p -r2.640 gram.y
--- src/backend/parser/gram.y	24 Nov 2008 08:46:03 -0000	2.640
+++ src/backend/parser/gram.y	25 Nov 2008 10:13:18 -0000
@@ -5623,6 +5623,16 @@ CreateDomainStmt:
 					n->domainname = $3;
 					n->typename = $5;
 					n->constraints = $6;
+					n->distinct_type = FALSE;
+					$$ = (Node *)n;
+				}
+			| CREATE TYPE_P any_name AS Typename
+				{
+					CreateDomainStmt *n = makeNode(CreateDomainStmt);
+					n->domainname = $3;
+					n->typename = $5;
+					n->constraints = NIL;
+					n->distinct_type = TRUE;
 					$$ = (Node *)n;
 				}
 		;
@@ -9477,7 +9487,6 @@ unreserved_keyword:
 			| ENABLE_P
 			| ENCODING
 			| ENCRYPTED
-			| ENUM_P
 			| ESCAPE
 			| EXCLUDING
 			| EXCLUSIVE
@@ -9664,6 +9673,7 @@ col_name_keyword:
 			| COALESCE
 			| DEC
 			| DECIMAL_P
+			| ENUM_P
 			| EXISTS
 			| EXTRACT
 			| FLOAT_P
Index: src/backend/parser/keywords.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/parser/keywords.c,v
retrieving revision 1.205
diff -u -3 -p -r1.205 keywords.c
--- src/backend/parser/keywords.c	27 Oct 2008 09:37:47 -0000	1.205
+++ src/backend/parser/keywords.c	25 Nov 2008 10:13:18 -0000
@@ -157,7 +157,7 @@ const ScanKeyword ScanKeywords[] = {
 	{"encoding", ENCODING, UNRESERVED_KEYWORD},
 	{"encrypted", ENCRYPTED, UNRESERVED_KEYWORD},
 	{"end", END_P, RESERVED_KEYWORD},
-	{"enum", ENUM_P, UNRESERVED_KEYWORD},
+	{"enum", ENUM_P, COL_NAME_KEYWORD},
 	{"escape", ESCAPE, UNRESERVED_KEYWORD},
 	{"except", EXCEPT, RESERVED_KEYWORD},
 	{"excluding", EXCLUDING, UNRESERVED_KEYWORD},
Index: src/backend/parser/parse_coerce.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/parser/parse_coerce.c,v
retrieving revision 2.171
diff -u -3 -p -r2.171 parse_coerce.c
--- src/backend/parser/parse_coerce.c	31 Oct 2008 08:39:21 -0000	2.171
+++ src/backend/parser/parse_coerce.c	25 Nov 2008 10:13:18 -0000
@@ -1867,15 +1867,25 @@ find_coercion_pathway(Oid targetTypeId, 
 	*funcid = InvalidOid;
 
 	/* Perhaps the types are domains; if so, look at their base types */
-	if (OidIsValid(sourceTypeId))
+	if (OidIsValid(sourceTypeId) && get_typtype(sourceTypeId) == TYPTYPE_DOMAIN)
 		sourceTypeId = getBaseType(sourceTypeId);
-	if (OidIsValid(targetTypeId))
+	if (OidIsValid(targetTypeId) && get_typtype(targetTypeId) == TYPTYPE_DOMAIN)
 		targetTypeId = getBaseType(targetTypeId);
 
 	/* Domains are always coercible to and from their base type */
 	if (sourceTypeId == targetTypeId)
 		return COERCION_PATH_RELABELTYPE;
 
+	/* Distinct types are castable AS ASSIGNMENT to and from their base types */
+	if (ccontext >= COERCION_ASSIGNMENT
+		&& ((OidIsValid(sourceTypeId)
+			 && get_typtype(sourceTypeId) == TYPTYPE_DISTINCT
+			 && getDirectBaseType(sourceTypeId) == targetTypeId)
+			|| (OidIsValid(targetTypeId)
+				&& get_typtype(targetTypeId) == TYPTYPE_DISTINCT
+				&& getDirectBaseType(targetTypeId) == sourceTypeId)))
+		return COERCION_PATH_RELABELTYPE;
+
 	/* Look in pg_cast */
 	tuple = SearchSysCache(CASTSOURCETARGET,
 						   ObjectIdGetDatum(sourceTypeId),
@@ -2033,6 +2043,7 @@ find_typmod_coercion_function(Oid typeId
 	/* Check for a varlena array type (and not a domain) */
 	if (typeForm->typelem != InvalidOid &&
 		typeForm->typlen == -1 &&
+		typeForm->typtype != TYPTYPE_DISTINCT &&
 		typeForm->typtype != TYPTYPE_DOMAIN)
 	{
 		/* Yes, switch our attention to the element type */
Index: src/backend/tcop/utility.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/tcop/utility.c,v
retrieving revision 1.301
diff -u -3 -p -r1.301 utility.c
--- src/backend/tcop/utility.c	7 Nov 2008 18:25:06 -0000	1.301
+++ src/backend/tcop/utility.c	25 Nov 2008 10:13:18 -0000
@@ -1291,7 +1291,11 @@ CreateCommandTag(Node *parsetree)
 			break;
 
 		case T_CreateDomainStmt:
-			tag = "CREATE DOMAIN";
+		{
+			CreateDomainStmt *stmt = (CreateDomainStmt *) parsetree;
+
+			tag = (stmt->distinct_type) ? "CREATE TYPE" : "CREATE DOMAIN";
+		}
 			break;
 
 		case T_CreateSchemaStmt:
Index: src/backend/utils/adt/format_type.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/format_type.c,v
retrieving revision 1.50
diff -u -3 -p -r1.50 format_type.c
--- src/backend/utils/adt/format_type.c	25 Mar 2008 22:42:44 -0000	1.50
+++ src/backend/utils/adt/format_type.c	25 Nov 2008 10:13:18 -0000
@@ -147,6 +147,7 @@ format_type_internal(Oid type_oid, int32
 
 	if (array_base_type != InvalidOid &&
 		typeform->typstorage != 'p' &&
+		typeform->typtype != TYPTYPE_DISTINCT &&
 		typeform->typtype != TYPTYPE_DOMAIN)
 	{
 		/* Switch our attention to the array element type */
Index: src/backend/utils/adt/xml.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/xml.c,v
retrieving revision 1.81
diff -u -3 -p -r1.81 xml.c
--- src/backend/utils/adt/xml.c	10 Nov 2008 18:02:20 -0000	1.81
+++ src/backend/utils/adt/xml.c	25 Nov 2008 10:13:18 -0000
@@ -2872,7 +2872,7 @@ map_sql_typecoll_to_xmlschema_types(List
 		}
 	}
 
-	/* add base types of domains */
+	/* add base types of distinct types and domains */
 	foreach(cell0, uniquetypes)
 	{
 		Oid			typid = lfirst_oid(cell0);
@@ -3056,7 +3056,7 @@ map_sql_type_to_xmlschema_type(Oid typeo
 				break;
 
 			default:
-				if (get_typtype(typeoid) == TYPTYPE_DOMAIN)
+				if (get_typtype(typeoid) == TYPTYPE_DISTINCT || get_typtype(typeoid) == TYPTYPE_DOMAIN)
 				{
 					Oid			base_typeoid;
 					int32		base_typmod = -1;
Index: src/backend/utils/cache/lsyscache.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/cache/lsyscache.c,v
retrieving revision 1.160
diff -u -3 -p -r1.160 lsyscache.c
--- src/backend/utils/cache/lsyscache.c	28 Sep 2008 19:51:40 -0000	1.160
+++ src/backend/utils/cache/lsyscache.c	25 Nov 2008 10:13:18 -0000
@@ -2032,7 +2032,7 @@ get_typdefault(Oid typid)
 
 /*
  * getBaseType
- *		If the given type is a domain, return its base type;
+ *		If the given type is a distinct type or domain, return its base type;
  *		otherwise return the type's own OID.
  */
 Oid
@@ -2045,7 +2045,7 @@ getBaseType(Oid typid)
 
 /*
  * getBaseTypeAndTypmod
- *		If the given type is a domain, return its base type and typmod;
+ *		If the given type is a distinct type or domain, return its base type and typmod;
  *		otherwise return the type's own OID, and leave *typmod unchanged.
  *
  * Note that the "applied typmod" should be -1 for every domain level
@@ -2069,9 +2069,9 @@ getBaseTypeAndTypmod(Oid typid, int32 *t
 		if (!HeapTupleIsValid(tup))
 			elog(ERROR, "cache lookup failed for type %u", typid);
 		typTup = (Form_pg_type) GETSTRUCT(tup);
-		if (typTup->typtype != TYPTYPE_DOMAIN)
+		if (typTup->typtype != TYPTYPE_DISTINCT && typTup->typtype != TYPTYPE_DOMAIN)
 		{
-			/* Not a domain, so done */
+			/* Not a distinct type or domain, so done */
 			ReleaseSysCache(tup);
 			break;
 		}
@@ -2087,6 +2087,30 @@ getBaseTypeAndTypmod(Oid typid, int32 *t
 }
 
 /*
+ * getDirectBaseType
+ *		If the given type is a distinct type or domain, return its direct base type;
+ *		otherwise return the type's own OID.
+ */
+Oid
+getDirectBaseType(Oid typid)
+{
+	HeapTuple	tup;
+	Form_pg_type typTup;
+
+	tup = SearchSysCache(TYPEOID,
+						 ObjectIdGetDatum(typid),
+						 0, 0, 0);
+	if (!HeapTupleIsValid(tup))
+		elog(ERROR, "cache lookup failed for type %u", typid);
+	typTup = (Form_pg_type) GETSTRUCT(tup);
+	if (typTup->typtype == TYPTYPE_DISTINCT || typTup->typtype == TYPTYPE_DOMAIN)
+		typid = typTup->typbasetype;
+		
+	ReleaseSysCache(tup);
+	return typid;
+}
+
+/*
  * get_typavgwidth
  *
  *	  Given a type OID and a typmod value (pass -1 if typmod is unknown),
Index: src/backend/utils/fmgr/funcapi.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/fmgr/funcapi.c,v
retrieving revision 1.42
diff -u -3 -p -r1.42 funcapi.c
--- src/backend/utils/fmgr/funcapi.c	25 Aug 2008 22:42:34 -0000	1.42
+++ src/backend/utils/fmgr/funcapi.c	25 Nov 2008 10:13:18 -0000
@@ -643,6 +643,7 @@ get_type_func_class(Oid typid)
 		case TYPTYPE_COMPOSITE:
 			return TYPEFUNC_COMPOSITE;
 		case TYPTYPE_BASE:
+		case TYPTYPE_DISTINCT:
 		case TYPTYPE_DOMAIN:
 		case TYPTYPE_ENUM:
 			return TYPEFUNC_SCALAR;
Index: src/bin/pg_dump/pg_dump.c
===================================================================
RCS file: /cvsroot/pgsql/src/bin/pg_dump/pg_dump.c,v
retrieving revision 1.505
diff -u -3 -p -r1.505 pg_dump.c
--- src/bin/pg_dump/pg_dump.c	9 Nov 2008 21:24:32 -0000	1.505
+++ src/bin/pg_dump/pg_dump.c	25 Nov 2008 10:13:18 -0000
@@ -134,6 +134,7 @@ static void dumpNamespace(Archive *fout,
 static void dumpType(Archive *fout, TypeInfo *tinfo);
 static void dumpBaseType(Archive *fout, TypeInfo *tinfo);
 static void dumpEnumType(Archive *fout, TypeInfo *tinfo);
+static void dumpDistinctType(Archive *fout, TypeInfo *tinfo);
 static void dumpDomain(Archive *fout, TypeInfo *tinfo);
 static void dumpCompositeType(Archive *fout, TypeInfo *tinfo);
 static void dumpShellType(Archive *fout, ShellTypeInfo *stinfo);
@@ -5755,6 +5756,8 @@ dumpType(Archive *fout, TypeInfo *tinfo)
 	/* Dump out in proper style */
 	if (tinfo->typtype == TYPTYPE_BASE)
 		dumpBaseType(fout, tinfo);
+	else if (tinfo->typtype == TYPTYPE_DISTINCT)
+		dumpDistinctType(fout, tinfo);
 	else if (tinfo->typtype == TYPTYPE_DOMAIN)
 		dumpDomain(fout, tinfo);
 	else if (tinfo->typtype == TYPTYPE_COMPOSITE)
@@ -6210,6 +6213,82 @@ dumpBaseType(Archive *fout, TypeInfo *ti
 }
 
 /*
+ * dumpDistinctType
+ *	  writes out to fout the queries to recreate a user-defined distinct type
+ */
+static void
+dumpDistinctType(Archive *fout, TypeInfo *tinfo)
+{
+	PQExpBuffer q = createPQExpBuffer();
+	PQExpBuffer delq = createPQExpBuffer();
+	PQExpBuffer query = createPQExpBuffer();
+	PGresult   *res;
+	int			ntups;
+	char	   *typdefn;
+
+	/* Set proper schema search path so type references list correctly */
+	selectSourceSchema(tinfo->dobj.namespace->dobj.name);
+
+	/* Fetch type specific details */
+	appendPQExpBuffer(query, "SELECT pg_catalog.format_type(typbasetype, typtypmod) as typdefn "
+					  "FROM pg_catalog.pg_type "
+					  "WHERE oid = '%u'::pg_catalog.oid",
+					  tinfo->dobj.catId.oid);
+
+	res = PQexec(g_conn, query->data);
+	check_sql_result(res, g_conn, query->data, PGRES_TUPLES_OK);
+
+	/* Expecting a single result only */
+	ntups = PQntuples(res);
+	if (ntups != 1)
+	{
+		write_msg(NULL, "query returned %d rows instead of one: %s\n",
+				  ntups, query->data);
+		exit_nicely();
+	}
+
+	typdefn = PQgetvalue(res, 0, PQfnumber(res, "typdefn"));
+
+	appendPQExpBuffer(q,
+					  "CREATE TYPE %s AS %s",
+					  fmtId(tinfo->dobj.name),
+					  typdefn);
+
+	PQclear(res);
+
+	appendPQExpBuffer(q, ";\n");
+
+	/*
+	 * DROP must be fully qualified in case same name appears in pg_catalog
+	 */
+	appendPQExpBuffer(delq, "DROP TYPE %s.",
+					  fmtId(tinfo->dobj.namespace->dobj.name));
+	appendPQExpBuffer(delq, "%s;\n",
+					  fmtId(tinfo->dobj.name));
+
+	ArchiveEntry(fout, tinfo->dobj.catId, tinfo->dobj.dumpId,
+				 tinfo->dobj.name,
+				 tinfo->dobj.namespace->dobj.name,
+				 NULL,
+				 tinfo->rolname, false,
+				 "TYPE", q->data, delq->data, NULL,
+				 tinfo->dobj.dependencies, tinfo->dobj.nDeps,
+				 NULL, NULL);
+
+	/* Dump Type Comments */
+	resetPQExpBuffer(q);
+
+	appendPQExpBuffer(q, "TYPE %s", fmtId(tinfo->dobj.name));
+	dumpComment(fout, q->data,
+				tinfo->dobj.namespace->dobj.name, tinfo->rolname,
+				tinfo->dobj.catId, 0, tinfo->dobj.dumpId);
+
+	destroyPQExpBuffer(q);
+	destroyPQExpBuffer(delq);
+	destroyPQExpBuffer(query);
+}
+
+/*
  * dumpDomain
  *	  writes out to fout the queries to recreate a user-defined domain
  */
Index: src/include/catalog/pg_type.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/catalog/pg_type.h,v
retrieving revision 1.203
diff -u -3 -p -r1.203 pg_type.h
--- src/include/catalog/pg_type.h	21 Nov 2008 18:49:24 -0000	1.203
+++ src/include/catalog/pg_type.h	25 Nov 2008 10:13:18 -0000
@@ -60,7 +60,7 @@ CATALOG(pg_type,1247) BKI_BOOTSTRAP
 
 	/*
 	 * typtype is 'b' for a base type, 'c' for a composite type (e.g., a
-	 * table's rowtype), 'd' for a domain type, 'e' for an enum type, or 'p'
+	 * table's rowtype), 'd' for a domain type, 'D' for a distinct type, 'e' for an enum type, or 'p'
 	 * for a pseudo-type.  (Use the TYPTYPE macros below.)
 	 *
 	 * If typtype is 'c', typrelid is the OID of the class' entry in pg_class.
@@ -632,6 +632,7 @@ DATA(insert OID = 3500 ( anyenum		PGNSP 
 #define  TYPTYPE_BASE		'b' /* base type (ordinary scalar type) */
 #define  TYPTYPE_COMPOSITE	'c' /* composite (e.g., table's rowtype) */
 #define  TYPTYPE_DOMAIN		'd' /* domain over another type */
+#define  TYPTYPE_DISTINCT	'D' /* distinct type based on another type */
 #define  TYPTYPE_ENUM		'e' /* enumerated type */
 #define  TYPTYPE_PSEUDO		'p' /* pseudo-type */
 
Index: src/include/nodes/parsenodes.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/nodes/parsenodes.h,v
retrieving revision 1.379
diff -u -3 -p -r1.379 parsenodes.h
--- src/include/nodes/parsenodes.h	24 Nov 2008 08:46:04 -0000	1.379
+++ src/include/nodes/parsenodes.h	25 Nov 2008 10:13:18 -0000
@@ -1461,6 +1461,7 @@ typedef struct CreateDomainStmt
 	List	   *domainname;		/* qualified name (list of Value strings) */
 	TypeName   *typename;		/* the base type */
 	List	   *constraints;	/* constraints (list of Constraint nodes) */
+	bool		distinct_type;	/* create distinct type rather than domain */
 } CreateDomainStmt;
 
 /* ----------------------
Index: src/include/utils/lsyscache.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/utils/lsyscache.h,v
retrieving revision 1.126
diff -u -3 -p -r1.126 lsyscache.h
--- src/include/utils/lsyscache.h	28 Sep 2008 19:51:40 -0000	1.126
+++ src/include/utils/lsyscache.h	25 Nov 2008 10:13:18 -0000
@@ -123,6 +123,7 @@ extern void getTypeBinaryOutputInfo(Oid 
 extern Oid	get_typmodin(Oid typid);
 extern Oid	getBaseType(Oid typid);
 extern Oid	getBaseTypeAndTypmod(Oid typid, int32 *typmod);
+extern Oid	getDirectBaseType(Oid typid);
 extern int32 get_typavgwidth(Oid typid, int32 typmod);
 extern int32 get_attavgwidth(Oid relid, AttrNumber attnum);
 extern bool get_attstatsslot(HeapTuple statstuple,
Index: src/interfaces/ecpg/preproc/parse.pl
===================================================================
RCS file: /cvsroot/pgsql/src/interfaces/ecpg/preproc/parse.pl,v
retrieving revision 1.1
diff -u -3 -p -r1.1 parse.pl
--- src/interfaces/ecpg/preproc/parse.pl	14 Nov 2008 10:01:04 -0000	1.1
+++ src/interfaces/ecpg/preproc/parse.pl	25 Nov 2008 10:13:18 -0000
@@ -60,6 +60,7 @@ $replace_types{'Sconst'} = 'ignore';
 $replace_line{'fetch_direction'} = 'ignore';
 $replace_line{"opt_array_boundsopt_array_bounds'['Iconst']'"} = 'ignore';
 $replace_line{'col_name_keywordCHAR_P'} = 'ignore';
+$replace_line{'col_name_keywordENUM_P'} = 'ignore';
 $replace_line{'col_name_keywordINT_P'} = 'ignore';
 $replace_line{'col_name_keywordVALUES'} = 'ignore';
 $replace_line{'reserved_keywordTO'} = 'ignore';
Index: src/pl/plpgsql/src/pl_comp.c
===================================================================
RCS file: /cvsroot/pgsql/src/pl/plpgsql/src/pl_comp.c,v
retrieving revision 1.132
diff -u -3 -p -r1.132 pl_comp.c
--- src/pl/plpgsql/src/pl_comp.c	5 Nov 2008 00:07:53 -0000	1.132
+++ src/pl/plpgsql/src/pl_comp.c	25 Nov 2008 10:13:19 -0000
@@ -1725,6 +1725,7 @@ build_datatype(HeapTuple typeTup, int32 
 	switch (typeStruct->typtype)
 	{
 		case TYPTYPE_BASE:
+		case TYPTYPE_DISTINCT:
 		case TYPTYPE_DOMAIN:
 		case TYPTYPE_ENUM:
 			typ->ttype = PLPGSQL_TTYPE_SCALAR;