[Mimedefang] Mail::SpamAssassin::BayesStore::SQL database persistence.

[Sevo Stille]

Matthew Schumacher wrote:

> In fact I looked that the performance benchmarks on the spamassassin
> site: http://wiki.apache.org/spamassassin/BayesBenchmarkResults and they
>  show postgres to be a terrible performer which would be true if the are
> not using persistent database connections.

Going through SpamAssassin/BayesStore/SQL.pm, it rather looks as if SA
were reusing any existing connection - that is, if SA is called
persistently, so will its connections. Don't know whether the MD method
of calling SA spoils that, though.

At any rate with my installation, SA/pg seems to be mostly slowed down
by the fact that the database is poorly indexed - indexing the most
significant search fields (bayes_seen(msgid), bayes_token(token) and id
throughout all tables) and doing a vacuum optimize run did improve
performance quite significantly.

> So the question is, is there a way to make SA use persistent
> connections?  

If the SA instances get scrapped, you could replace the DBI->connect
call with DBI->connect_cached, and disable the corresponding disconnect.

> I read though the docs and didn't see anything.  Perhaps a
> way to create a persistent connection in MD and pass it to the SA module?

That would create a interdependency between MD and a modification to MD
- very ugly in terms of maintenance.

Sevo