Autor: Jim Cheetham Data: Para: exim users Assunto: Re: [exim] Misunderstanding match_domain and sqlite ...
On Mon, 2010-04-05 at 11:19 -0400, W B Hacker wrote: > Now -- all that said ... why do you feel you need the extra:
>
> 'if match_domain....' part of the test???
>
> JM2CW, but seems to be advantageous to JFDI in one SQL call AND NOT also ask
> Exim to do a 'match' ....
Well, the idea was to build up a set of active domains once, and then to
re-use that list in different contexts; I was expecting that would lead
to only one DB lookup, even if I had multiple tests.
Also, if we need to change the query logic at some point, I only have to
do it in one place (I guess I could still use a macro to achieve that
though).
> ..or the reverse - eg not use SQL for this test at all. Exim reads all manner of
> DB just fine on its own and with fewer things to maintain.
This exim is handling multiple virtual domain customers defined from a
large database elsewhere, and I didn't want to have a full database
running on the mail machine; so the sqlite seemed like a reasonable
compromise that would collect all the mail customer information in one
place, and can be queried in ways that the provisioning system may not
have anticipated.
Having multiple text files pre-populated with the results of various
logical queries may work well with exim, but I'd hate to have to keep on
checking their referential integrity ...