Rename the built-in tablespaces to pg_default and pg_global, and prohibit

creation of user-defined tablespaces with names starting with 'pg_', as
per suggestion of Chris K-L.  Also install admin-guide tablespace
documentation from Gavin.

src/backend/catalog/catalog.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/catalog/catalog.c,v 1.53 2004/06/21 01:04:41 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/catalog/catalog.c,v 1.54 2004/06/21 04:06:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -119,8 +119,7 @@ GetDatabasePath(Oid dbNode, Oid spcNode)
  *
  *		We now just test if the relation is in the system catalog namespace;
  *		so it's no longer necessary to forbid user relations from having
- *		names starting with pg_.  Now only schema names have the pg_
- *		distinction/requirement.
+ *		names starting with pg_.
  */
 bool
 IsSystemRelation(Relation relation)
@@ -200,8 +199,8 @@ IsToastNamespace(Oid namespaceId)
  *		True iff name starts with the pg_ prefix.
  *
  *		For some classes of objects, the prefix pg_ is reserved for
- *		system objects only. As of 7.3, this is now only true for
- *		schema names.
+ *		system objects only.  As of 7.5, this is only true for
+ *		schema and tablespace names.
  */
 bool
 IsReservedName(const char *name)

src/backend/commands/tablespace.c

@@ -19,8 +19,8 @@
  * Thus the full path to an arbitrary file is
  *			$PGDATA/pg_tblspc/spcoid/dboid/relfilenode
  *
- * There are two tablespaces created at initdb time: global (for shared
- * tables) and default (for everything else).  For backwards compatibility
+ * There are two tablespaces created at initdb time: pg_global (for shared
+ * tables) and pg_default (for everything else).  For backwards compatibility
  * and to remain functional on platforms without symlinks, these tablespaces
  * are accessed specially: they are respectively
  *			$PGDATA/global/relfilenode
@@ -45,7 +45,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablespace.c,v 1.2 2004/06/21 01:04:42 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablespace.c,v 1.3 2004/06/21 04:06:06 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -233,6 +233,17 @@ CreateTableSpace(CreateTableSpaceStmt *stmt)
 				 errmsg("tablespace location \"%s\" is too long",
 						location)));
 
+	/*
+	 * Disallow creation of tablespaces named "pg_xxx"; we reserve this
+	 * namespace for system purposes.
+	 */
+	if (!allowSystemTableMods && IsReservedName(stmt->tablespacename))
+		ereport(ERROR,
+				(errcode(ERRCODE_RESERVED_NAME),
+				 errmsg("unacceptable tablespace name \"%s\"",
+						stmt->tablespacename),
+		errdetail("The prefix \"pg_\" is reserved for system tablespaces.")));
+
 	/*
 	 * Check that there is no other tablespace by this name.  (The
 	 * unique index would catch this anyway, but might as well give 

src/include/catalog/catversion.h

@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.238 2004/06/21 01:04:45 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.239 2004/06/21 04:06:07 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200406201
+#define CATALOG_VERSION_NO	200406202
 
 #endif

src/include/catalog/pg_tablespace.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_tablespace.h,v 1.1 2004/06/18 06:14:06 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_tablespace.h,v 1.2 2004/06/21 04:06:07 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -57,8 +57,8 @@ typedef FormData_pg_tablespace *Form_pg_tablespace;
 #define Anum_pg_tablespace_spclocation	3
 #define Anum_pg_tablespace_spcacl		4
 
-DATA(insert OID = 1663 ( default	PGUID "" _null_ ));
-DATA(insert OID = 1664 ( global		PGUID "" _null_ ));
+DATA(insert OID = 1663 ( pg_default	PGUID "" _null_ ));
+DATA(insert OID = 1664 ( pg_global	PGUID "" _null_ ));
 
 #define DEFAULTTABLESPACE_OID 1663
 #define GLOBALTABLESPACE_OID 1664