I really hope that I haven't missed anything in this one...

From: t-ishii@sra.co.jp

Attached are patches to enhance the multi-byte support.  (patches are
against 7/18 snapshot)

* determine encoding at initdb/createdb rather than compile time

Now initdb/createdb has an option to specify the encoding. Also, I
modified the syntax of CREATE DATABASE to accept encoding option. See
README.mb for more details.

For this purpose I have added new column "encoding" to pg_database.
Also pg_attribute and pg_class are changed to catch up the
modification to pg_database.  Actually I haved added pg_database_mb.h,
pg_attribute_mb.h and pg_class_mb.h. These are used only when MB is
enabled. The reason having separate files is I couldn't find a way to
use ifdef or whatever in those files. I have to admit it looks
ugly. No way.

* support for PGCLIENTENCODING when issuing COPY command

commands/copy.c modified.

* support for SQL92 syntax "SET NAMES"

See gram.y.

* support for LATIN2-5
* add UNICODE regression test case
* new test suite for MB

New directory test/mb added.

* clean up source files

Basic idea is to have MB's own subdirectory for easier maintenance.
These are include/mb and backend/utils/mb.

src/backend/utils/mb/variable.c

@@ -0,0 +1,73 @@
+/*
+ * This file contains some public functions
+ * related to show/set/reset variable commands.
+ * Tatsuo Ishii
+ * $Id: variable.c,v 1.1 1998/07/24 03:31:57 scrappy Exp $
+ */
+
+#include "mb/pg_wchar.h"
+
+bool
+parse_client_encoding(const char *value)
+{
+  int encoding;
+
+  encoding = pg_valid_client_encoding(value);
+  if (encoding < 0) {
+    elog(ERROR, "Client encoding %s is not supported", value);
+  } else {    
+    if (pg_set_client_encoding(encoding)) {
+      elog(ERROR, "Conversion between %s and %s is not supported",
+	   value, pg_encoding_to_char(GetDatabaseEncoding()));
+    }
+  }
+  return TRUE;
+}
+
+bool
+show_client_encoding()
+{
+  elog(NOTICE, "Current client encoding is %s",
+       pg_encoding_to_char(pg_get_client_encoding()));
+  return TRUE;
+}
+
+bool
+reset_client_encoding()
+{
+  int encoding;
+  char *env = getenv("PGCLIENTENCODING");
+
+  if (env) {
+    encoding = pg_char_to_encoding(env);
+    if (encoding < 0) {
+      encoding = GetDatabaseEncoding();
+    }
+  } else {
+    encoding = GetDatabaseEncoding();
+  }
+  pg_set_client_encoding(encoding);
+  return TRUE;
+}
+
+bool
+parse_server_encoding(const char *value)
+{
+  elog(NOTICE, "SET SERVER_ENCODING is not supported");
+  return TRUE;
+}
+
+bool
+show_server_encoding()
+{
+  elog(NOTICE, "Current server encoding is %s",
+       pg_encoding_to_char(GetDatabaseEncoding()));
+  return TRUE;
+}
+
+bool
+reset_server_encoding()
+{
+  elog(NOTICE, "RESET SERVER_ENCODING is not supported");
+  return TRUE;
+}