Hi,

> (firebird 2.1.5 on centos) 50Gb database
>
> Is there any reason why a process, upon noticing the transaction gap is>
> 20000& hence a sweep is required, should 'hang' (for hours), as if waiting
> for the sweep to complete.
>
> Is there any way I can tell (logging or process monitoring perhaps) when an
> automatic sweep is initiated, running or completed?

With 2.5.2 you would get log entries in firebird.log or more in-depth
insights with the Trace API.

In older Firebird versions, I vaguely remember that you could see a
separate database connection with a user called 'SQL Server'. Not sure
if this still applies to Firebird 2.x.

Regards,
Thomas