> This phrase makes one ponder:
>
> >keep climbing until I restart the Interbase Server service.
>
> Are you really running Firebird 1.5.2?
>
> ./heLen

Yes, we are. It just slipped. We have been using Interbase since 1997,
and Firebird since 0.9x. Currently we have many Firebird servers and
one Interbase 7.5 server. It's a habit. It's like if your have been
"xeroxing" all your life then you got a brand Z copier it take a while
to get used to the term "Zeeing".

Back to the topic, we don't use BDE anymore, mostly IB Objects and the
native component suit which used to be called IB Express that came
with Delphi 6. We always tried to keep the transactions as short as
possible. The only application that may have long running transactions
is an customer service app (which uses IB Objects) which uses mostly
read only queries. I have examined database stats for transaction gaps
(oldest snapshot, next transaction, etc.) and they were small (<5).
So, I am at a lost as to where I can look.

I am aware of the possibility of memory leak caused by UDFs (having
written a few and tested them for leak myself), but so far I found no
clue.

If all the connections are closed, and the database has no active
transaction, shouldn't the server release all the memory except for
the cache? Or is there something else I am missing. I am trying to
find a way to narrow down the causes.

Thank you for taking the time to respond.