--- In firebird-support@yahoogroups.com, Thomas <thomas@l...> wrote:

> Hi all,
>
> While browsing the knowledge base on ibphoenix I came across a
> Code-Sample in C on how to connect to Firebird/Interbase with

garbage

> collection disabled.
> The Code-Sample was for InterBase 5.
> Does it still make sense for FB1.5?

Thomas, AFAIK, yes. At least I can't remember any mentions on
disabling this feature and I follow FB evolution very carefully.

> I'm asking because I experienced performance problems (occasional

hangs

> from 8-24 seconds) with Firebird and PHP under heavy load.
> I suspect Firebird to be garbage collecting during these hangs, and

thus

> not answering to any queries.
>
> Would it help using connections with garbage collection disabled?

I would be very cautious about this. If you switch GC off and your
application really produce much garbage (lot of updates and deletes)
you'll see at the begining linear slowdown (server should check all
versions of each row at any access) and catastrophic degradation when
amount of garbage reaches some magic value (can't determine exactly).
And note if it occurs the only one you can do with database is backup
without GC and restore into new file. If your problem is really
related to mass updates/deletes and long running transactions I
recommend to re-design application. But I'm not sure it is really GC
problem. I encountered similar behaviour when migrated my production
database from FB1 on Red Hat 7.1 to FB1.5 and changed OS to RH 8 with
kernel 2.4.20 to support it. Still investigating this disabling some
(not really needed for me) RH system daemons step by step. If it
will'nt help I'll try to downgrade kernel to 2.4.18 to get rid of
kscand, I suspect new OS cache management strategy is the reason.

Best regards,
Alexander