Here's a patch to add unknownin/unknownout support. I also poked around

looking for places that assume UNKNOWN == TEXT. One of those was the
"SET" type in pg_type.h, which was using textin/textout. This one I took
care of in this patch. The other suspicious place was in
string_to_dataum (which is defined in both selfuncs.c and indxpath.c). I
wasn't too sure about those, so I left them be.

Joe Conway

src/backend/utils/adt/varlena.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.83 2002/04/15 07:54:37 ishii Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/varlena.c,v 1.84 2002/04/24 02:12:53 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -228,6 +228,46 @@ textout(PG_FUNCTION_ARGS)
 }
 
 
+/*
+ *		unknownin			- converts "..." to internal representation
+ */
+Datum
+unknownin(PG_FUNCTION_ARGS)
+{
+	char	   *inputStr = PG_GETARG_CSTRING(0);
+	unknown	   *result;
+	int			len;
+
+	len = strlen(inputStr) + VARHDRSZ;
+
+	result = (unknown *) palloc(len);
+	VARATT_SIZEP(result) = len;
+
+	memcpy(VARDATA(result), inputStr, len - VARHDRSZ);
+
+	PG_RETURN_UNKNOWN_P(result);
+}
+
+
+/*
+ *		unknownout			- converts internal representation to "..."
+ */
+Datum
+unknownout(PG_FUNCTION_ARGS)
+{
+	unknown	   *t = PG_GETARG_UNKNOWN_P(0);
+	int			len;
+	char	   *result;
+
+	len = VARSIZE(t) - VARHDRSZ;
+	result = (char *) palloc(len + 1);
+	memcpy(result, VARDATA(t), len);
+	result[len] = '\0';
+
+	PG_RETURN_CSTRING(result);
+}
+
+
 /* ========== PUBLIC ROUTINES ========== */
 
 /*

src/include/c.h

@@ -12,7 +12,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: c.h,v 1.117 2002/04/23 15:45:30 tgl Exp $
+ * $Id: c.h,v 1.118 2002/04/24 02:12:53 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -404,6 +404,7 @@ struct varlena
  */
 typedef struct varlena bytea;
 typedef struct varlena text;
+typedef struct varlena unknown;
 typedef struct varlena BpChar;	/* blank-padded char, ie SQL char(n) */
 typedef struct varlena VarChar; /* var-length char, ie SQL varchar(n) */
 

src/include/catalog/catversion.h

@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: catversion.h,v 1.122 2002/04/21 19:48:22 thomas Exp $
+ * $Id: catversion.h,v 1.123 2002/04/24 02:12:53 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200204211
+#define CATALOG_VERSION_NO	200204231
 
 #endif

src/include/catalog/pg_proc.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_proc.h,v 1.229 2002/04/21 19:48:23 thomas Exp $
+ * $Id: pg_proc.h,v 1.230 2002/04/24 02:12:53 momjian Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -237,6 +237,11 @@ DESCR("join selectivity of < and related operators on scalar datatypes");
 DATA(insert OID = 108 (  scalargtjoinsel   PGNSP PGUID 12 f t f t f s 3 701 "0 26 0" 100 0 0 100  scalargtjoinsel - _null_ ));
 DESCR("join selectivity of > and related operators on scalar datatypes");
 
+DATA(insert OID =  109 (  unknownin			   PGNSP PGUID 12 f t t i 1 f 705 "0" 100 0 0 100	unknownin - _null_ ));
+DESCR("(internal)");
+DATA(insert OID =  110 (  unknownout		   PGNSP PGUID 12 f t t i 1 f 23  "0" 100 0 0 100	unknownout - _null_ ));
+DESCR("(internal)");
+
 DATA(insert OID = 112 (  text			   PGNSP PGUID 12 f t t t f i 1  25 "23" 100 0 0 100  int4_text - _null_ ));
 DESCR("convert int4 to text");
 DATA(insert OID = 113 (  text			   PGNSP PGUID 12 f t t t f i 1  25 "21" 100 0 0 100  int2_text - _null_ ));

src/include/catalog/pg_type.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_type.h,v 1.120 2002/04/21 00:26:43 tgl Exp $
+ * $Id: pg_type.h,v 1.121 2002/04/24 02:12:53 momjian Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -302,7 +302,7 @@ DATA(insert OID = 30 (	oidvector  PGNSP PGUID INDEX_MAX_KEYS*4 -1 f b t \054 0
 DESCR("array of INDEX_MAX_KEYS oids, used in system tables");
 #define OIDVECTOROID	30
 
-DATA(insert OID = 32 (	SET		   PGNSP PGUID -1  -1 f b t \054 0   0 textin textout textin textout i p f 0 -1 0 _null_ _null_ ));
+DATA(insert OID = 32 (	SET		   PGNSP PGUID -1  -1 f b t \054 0   0 unknownin unknownout unknownin unknownout i p f 0 -1 0 _null_ _null_ ));
 DESCR("set of tuples");
 
 DATA(insert OID = 71 (	pg_type		 PGNSP PGUID 4 4 t c t \054 1247 0 int4in int4out int4in int4out i p f 0 -1 0 _null_ _null_ ));
@@ -366,7 +366,7 @@ DESCR("relative, limited-range time interval (Unix delta time)");
 DATA(insert OID = 704 (  tinterval PGNSP PGUID 12  47 f b t \054 0   0 tintervalin tintervalout tintervalin tintervalout i p f 0 -1 0 _null_ _null_ ));
 DESCR("(abstime,abstime), time interval");
 #define TINTERVALOID	704
-DATA(insert OID = 705 (  unknown   PGNSP PGUID -1  -1 f b t \054 0   0 textin textout textin textout i p f 0 -1 0 _null_ _null_ ));
+DATA(insert OID = 705 (  unknown   PGNSP PGUID -1  -1 f b t \054 0   0 unknownin unknownout unknownin unknownout i p f 0 -1 0 _null_ _null_ ));
 DESCR("");
 #define UNKNOWNOID		705
 

src/include/fmgr.h

@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: fmgr.h,v 1.19 2002/03/05 05:33:22 momjian Exp $
+ * $Id: fmgr.h,v 1.20 2002/04/24 02:12:53 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -185,6 +185,7 @@ extern struct varlena *pg_detoast_datum_slice(struct varlena * datum,
 /* DatumGetFoo macros for varlena types will typically look like this: */
 #define DatumGetByteaP(X)			((bytea *) PG_DETOAST_DATUM(X))
 #define DatumGetTextP(X)			((text *) PG_DETOAST_DATUM(X))
+#define DatumGetUnknownP(X)			((unknown *) PG_DETOAST_DATUM(X))
 #define DatumGetBpCharP(X)			((BpChar *) PG_DETOAST_DATUM(X))
 #define DatumGetVarCharP(X)			((VarChar *) PG_DETOAST_DATUM(X))
 /* And we also offer variants that return an OK-to-write copy */
@@ -200,6 +201,7 @@ extern struct varlena *pg_detoast_datum_slice(struct varlena * datum,
 /* GETARG macros for varlena types will typically look like this: */
 #define PG_GETARG_BYTEA_P(n)		DatumGetByteaP(PG_GETARG_DATUM(n))
 #define PG_GETARG_TEXT_P(n)			DatumGetTextP(PG_GETARG_DATUM(n))
+#define PG_GETARG_UNKNOWN_P(n)		DatumGetUnknownP(PG_GETARG_DATUM(n))
 #define PG_GETARG_BPCHAR_P(n)		DatumGetBpCharP(PG_GETARG_DATUM(n))
 #define PG_GETARG_VARCHAR_P(n)		DatumGetVarCharP(PG_GETARG_DATUM(n))
 /* And we also offer variants that return an OK-to-write copy */
@@ -239,6 +241,7 @@ extern struct varlena *pg_detoast_datum_slice(struct varlena * datum,
 /* RETURN macros for other pass-by-ref types will typically look like this: */
 #define PG_RETURN_BYTEA_P(x)   PG_RETURN_POINTER(x)
 #define PG_RETURN_TEXT_P(x)    PG_RETURN_POINTER(x)
+#define PG_RETURN_UNKNOWN_P(x) PG_RETURN_POINTER(x)
 #define PG_RETURN_BPCHAR_P(x)  PG_RETURN_POINTER(x)
 #define PG_RETURN_VARCHAR_P(x) PG_RETURN_POINTER(x)
 

src/include/utils/builtins.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: builtins.h,v 1.177 2002/04/18 20:01:11 tgl Exp $
+ * $Id: builtins.h,v 1.178 2002/04/24 02:12:53 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -414,6 +414,9 @@ extern List *textToQualifiedNameList(text *textval, const char *caller);
 extern bool SplitIdentifierString(char *rawstring, char separator,
 								  List **namelist);
 
+extern Datum unknownin(PG_FUNCTION_ARGS);
+extern Datum unknownout(PG_FUNCTION_ARGS);
+
 extern Datum byteain(PG_FUNCTION_ARGS);
 extern Datum byteaout(PG_FUNCTION_ARGS);
 extern Datum byteaoctetlen(PG_FUNCTION_ARGS);