[Dovecot] best choice of user database file to work with postfix?

[Phil Howard]

On Wed, Apr 21, 2010 at 10:58 AM, Peter Hessler <phessler at theapt.org> wrote:

> postfix:
>
> smtpd_sasl_type = dovecot
> smtpd_sasl_path = private/auth
>
>
> dovecot:
>
> auth default {
>  socket listen {
>    client {
>      path = /var/spool/postfix/private/auth
>      user = _postfix
>      group = wheel
>      mode = 0660
>    }
>  }
> }
>
> Then configure your favorite auth mechanism for dovecot.  Let bake for 20
> minutes, add salt for taste.
>

This looks interesting.  That would basically be run through Dovecot with a
named socket I take it.  How would the lookup table type be specified for
local_recipient_maps in Postfix to use this?