PostgreSQL8.3（Mac　OSX、MacPortsでインストール）でEUC_JPのデータベースを作成しようとしたら、以下のようにエラーになった。

$ createdb -U postgres -E EUC_JP dbname
createdb: database creation failed: ERROR:  encoding EUC_JP does not match server's locale ja_JP.UTF-8
DETAIL:  The server's LC_CTYPE setting requires encoding UTF8.

以下のようにオプションに　--encoding=UTF8 --no-locale　をつけてinitdbしなおしたら、作成できるようになった。

$ sudo rm -rf /opt/local/var/db/postgresql83/defaultdb
$ sudo mkdir -p /opt/local/var/db/postgresql83/defaultdb
$ sudo chown postgres:postgres /opt/local/var/db/postgresql83/defaultdb
$ sudo su postgres -c '/opt/local/lib/postgresql83/bin/initdb -D /opt/local/var/db/postgresql83/defaultdb --encoding=UTF8 --no-locale'
The files belonging to this database system will be owned by user "postgres".
This user must also own the server process.
The database cluster will be initialized with locale C.
The default text search configuration will be set to "english".
fixing permissions on existing directory /opt/local/var/db/postgresql83/defaultdb ... ok
creating subdirectories ... ok
selecting default max_connections ... 20
selecting default shared_buffers/max_fsm_pages ... 1600kB/20000
creating configuration files ... ok
creating template1 database in /opt/local/var/db/postgresql83/defaultdb/base/1 ... ok
initializing pg_authid ... ok
initializing dependencies ... ok
creating system views ... ok
loading system objects' descriptions ... ok
creating conversions ... ok
creating dictionaries ... ok
setting privileges on built-in objects ... ok
creating information schema ... ok
vacuuming database template1 ... ok
copying template1 to template0 ... ok
copying template1 to postgres ... ok
WARNING: enabling "trust" authentication for local connections
You can change this by editing pg_hba.conf or using the -A option the
next time you run initdb.
Success. You can now start the database server using:
    /opt/local/lib/postgresql83/bin/postgres -D /opt/local/var/db/postgresql83/defaultdb
or
    /opt/local/lib/postgresql83/bin/pg_ctl -D /opt/local/var/db/postgresql83/defaultdb -l logfile start