Subject RE: Database performance slowdown
Author Leyne, Sean
> We are investigating an issue with one of our systems where it gradually
> slows down during the course of a day.
> We have our  epos system that we write ourselves using Delphi XE2 and the
> IBX components.
> We have a group of tables that are updated during the end of sale save
> process.
> Typically this whole save process takes milliseconds, but on one particular site
> we see it taking several seconds and occasionally taking up to 35 seconds.

You should run gstat -h to check the transaction counter values. Please post the details here for review.

> We have done some digging  into the behaviour of Firebird, we are currently
> using v2.5, and it appears that Firebird needs to check the entire chain of
> back versions when reading a record from the database. Is this the
> cooperative Garbage Collection process running?
> It seems like it would be logical for a lookup to only search back records until
> it finds the record that is supposed to be visible to it, but it appears to go all
> the way back.

This would be a sign that there is a db connection that is not committing transactions as it should.