Subject RE: [firebird-support] Over-sweeping
Author Thomas Steinmaurer
> Garbage is not much problem - it can be removed
> by sweep, but sooner or later it will be removed
> by normal cooperative garbage collection anyway.
> What is the problem is stuck OIT, which can slow down
> starting new transactions and increase memory demands
> for each snapshot transaction.
> But even OIT is not problem in most applications,
> since it can stuck only on some relatively rare occasions -
> either after server crash, or after rollback of transaction
> that updated lot of data.
> There are only two ways how to get rid of stuck OIT -
> by sweep, or by creating new database (i.e. backup/restore).
> Regarding auto-sweep - it dos not start every 20000 transactions !!!
> It starts when difference between OIT and OAT is 20000 !
> which usually means when OIT get stuck; in most applications
> automatic sweep will never start !

Huch, nice to see that's not only me, but also Ivan, who
mentions the OAT and *not* the next transaction, when talking
about the sweep interval. Many people still think that the
sweep interval has something to do with the next transaction.


Best Regards,
Thomas Steinmaurer
LogManager Serie - Logging/Auditing Suites supporting
InterBase, Firebird, Advantage Database and MS SQL Server
Upscene Productions