binary migration: pg_migrator

Add comments about places where system oids have to be preserved for
binary migration.

src/backend/catalog/pg_enum.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/catalog/pg_enum.c,v 1.9 2009/01/01 17:23:37 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/catalog/pg_enum.c,v 1.10 2009/12/19 00:47:57 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -67,6 +67,10 @@ EnumValuesCreate(Oid enumTypeOid, List *vals)
 	oids = (Oid *) palloc(n * sizeof(Oid));
 	for (i = 0; i < n; i++)
 	{
+		/*
+		 *	The pg_enum.oid is stored in user tables.  This oid must be
+		 *	preserved by binary upgrades.
+		 */
 		oids[i] = GetNewOid(pg_enum);
 	}
 

src/backend/commands/typecmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/typecmds.c,v 1.139 2009/12/07 05:22:21 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/typecmds.c,v 1.140 2009/12/19 00:47:57 momjian Exp $
  *
  * DESCRIPTION
  *	  The "DefineFoo" routines take the parse tree and pick out the
@@ -531,6 +531,12 @@ DefineType(List *names, List *parameters)
 	 * now have TypeCreate do all the real work.
 	 */
 	typoid =
+		/*
+		 *	The pg_type.oid is stored in user tables as array elements
+		 *	(base types) in ArrayType and in composite types in
+		 *	DatumTupleFields.  This oid must be preserved by binary
+		 *	upgrades.
+		 */
 		TypeCreate(InvalidOid,	/* no predetermined type OID */
 				   typeName,	/* type name */
 				   typeNamespace,		/* namespace */

src/backend/utils/adt/arrayfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.161 2009/09/04 11:20:22 heikki Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/arrayfuncs.c,v 1.162 2009/12/19 00:47:57 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -328,6 +328,11 @@ array_in(PG_FUNCTION_ARGS)
 	SET_VARSIZE(retval, nbytes);
 	retval->ndim = ndim;
 	retval->dataoffset = dataoffset;
+	/*
+	 *	This comes from the array's pg_type.typelem (which points to the
+	 *	base data type's pg_type.oid) and stores system oids in user tables.
+	 *	This oid must be preserved by binary upgrades.
+	 */
 	retval->elemtype = element_type;
 	memcpy(ARR_DIMS(retval), dim, ndim * sizeof(int));
 	memcpy(ARR_LBOUND(retval), lBound, ndim * sizeof(int));

src/backend/utils/adt/enum.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/enum.c,v 1.7 2009/01/01 17:23:49 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/enum.c,v 1.8 2009/12/19 00:47:57 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -56,6 +56,10 @@ enum_in(PG_FUNCTION_ARGS)
 						format_type_be(enumtypoid),
 						name)));
 
+	/*
+	 *	This comes from pg_enum.oid and stores system oids in user tables.
+	 *	This oid must be preserved by binary upgrades.
+	 */
 	enumoid = HeapTupleGetOid(tup);
 
 	ReleaseSysCache(tup);

src/backend/utils/adt/rowtypes.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/rowtypes.c,v 1.25 2009/06/11 14:49:04 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/rowtypes.c,v 1.26 2009/12/19 00:47:57 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -97,6 +97,11 @@ record_in(PG_FUNCTION_ARGS)
 				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 		   errmsg("input of anonymous composite types is not implemented")));
 	tupTypmod = -1;				/* for all non-anonymous types */
+	/*
+	 *	This comes from the composite type's pg_type.oid and
+	 *	stores system oids in user tables, specifically DatumTupleFields.
+	 *	This oid must be preserved by binary upgrades.
+	 */
 	tupdesc = lookup_rowtype_tupdesc(tupType, tupTypmod);
 	ncolumns = tupdesc->natts;