> I have a website with PHP and a Firebird database. It looks like the Firebird database becomes very slow and I don't know, how to find where and why.
>
> My database is 15GB, the biggest table has about 30 million records.
>
> Right now I try to create the statistics, but it takes for ever. At the same time I try to monitor the database with the Sinatica tool. OAT and Next transaction are close, no GC pending.

I would run gstat -h anyway.

> What I see is a lot warnings like "invalid char set", but I think, this has nothing to do with performance.
>
> I'm also not aware of any statement not using indexes or so.

Hmm, pretty dangerous. Although it won't help with what happened in the
past, but use the Trace API, if you are using Firebird 2.5, to detect
natural scan statements, long execution time etc ...

> What can I do? How do I find the bottle necks? It must be in Firebird, but I don't know, what I do wrong.

1) gstat -h
2) MON$ tables
3) Firebir 2.5 Trace API


--
With regards,
Thomas Steinmaurer

* Upscene Productions - Database Tools for Developers
http://www.upscene.com/

* My Blog
http://blog.upscene.com/thomas/index.php

* Firebird Foundation Committee Member
http://www.firebirdsql.org/en/firebird-foundation/