[Dovecot] mysql lookup on another host performance q?

[Voytek Eymont]

Hi, new to dovecot

I'm setting a small postfix/dovecot server for virtual domain/users in mysql

dovecot is on one host, mysql on another

seems to be working, but I'm concerned over performance overhead of this
setup;

dumb Q, is there any 'proxy mysql' or cacheing option I can use ?

any suggestions appreciated

also, my mail users as set as 5000/5000
virtual_gid_maps = static:5000
virtual_uid_maps = static:5000

so, I should use uid/gid 5000/5000 in query below, yes ?

thanks

-- 
Voytek

---------------------------------------------------------
# dovecot --version
1.2.9

Linux 2.6.32-21-generic-pae #32-Ubuntu SMP Fri Apr 16 09:39:35 UTC 2010
i686 GNU/Linux

# grep -v '^ *\(#.*\)\?$' dovecot-sql.conf
driver = mysql
connect = host=host.tld dbname=ddd user=ccc password=xxx

user_query = SELECT concat('/var/mail/vhosts/', maildir) as home,
concat('maildir:/var/mail/vhosts/', maildir) as mail, 5000 AS uid, 5000 AS
gid, concat('maildir:storage=', quota) AS quota FROM mailbox WHERE
username = '%u' AND active = '1'
default_pass_scheme = MD5
user_query = SELECT '/var/mail/vhosts/%d/%n@%d' as home,
'maildir:/var/mail/vhosts/%d/%n@%d' as mail, 5000 AS uid, 5000 AS gid,
concat('dirsize:storage=', quota) AS quota FROM mailbox WHERE username =
'%u' AND active = '1'
password_query = SELECT username as user, password,
'/var/mail/vhosts/%d/%n@%d' as userdb_home,
'maildir:/var/mail/vhosts/%d/%n@%d' as userdb_mail, 5000 as userdb_uid,
5000 as userdb_gid FROM mailbox WHERE username = '%u' AND active = '1'