Re: [Exim] Persistent DB connections to MySQL database

Dear Philip,

> For the very fastest performance, I would think you would do better to
> abstract the relevant data from your DB or LDAP, and build local cdb
> files for Exim to work off. Of course, this gives a delay between making
> a database change and its taking effect, but you can arrange for that to
> be relatively short. It also means that mail continues to flow when the
> database is down.

I found your answer to this question very useful. I started off with Exim
by building NDBM files and then moved to CDB for increased performance.
However, the database is only being rebuilt a few times a day from a flat
file. We now need to move to set up where the mail hub maintains its own
database which can be updated on the fly.

I was going to use MySQL but I have realised that I don't need the power
of MySQL because I still only need to make single key look ups. I was
thinking I could instead go back to Exim using NDBM and update that on the
fly. What I would like to know is whether it would be safe to update the
NDBM database used by Exim directly or whether I would need to lock it.
If it is not safe then your suggestion of maintaining a CDB "cache" would
seem to be a good way to go.

Thank you in anticipation of your response.

Richard
--
Richard Gilbert
Corporate Information and Computing Services
University of Sheffield, Sheffield, S10 2TN, UK
Phone: +44 114 222 3028 Fax: +44 114 222 3040