Subject Over-sweeping
Author JS.staff

So long as we've agreed that sweeping doesn't have any drawbacks (beyond
slowdown during the sweep itself). I certainly got the impression from
our chat you thought nightly sweeping was a bad idea.

I would absolutely agree that backup/restore is a 'better' solution from
the point of view of the db file structure - it would just also involve
making the database unavailable, and introducing the possibility of
corruption if someone attempts to connect while restore takes place.

Hence I don't use it for regular maintenance.

On the point of 20,000 transaction-auto-sweep being "never meant to be a
frequent event" - it would happen every couple of days for me!
Disconnected and web-based systems necessarily have a higher transaction
count than 'connected' apps, I suppose. Ie 1 transaction to populate the
menu, a second to populate the edit screen, and a third to do the
UPDATE. Multiply that by 10 users and a couple of hundred views / edits
per day, and it mounts up!

Helen, thanks for the info!



I didn't say *ANY* sweeping - I said *TOO MUCH* sweeping is not required
and according to the Interbase Operations Guide p128,
On the other hand, frequent database sweeps can reduce application
performance. Raising the sweep interval could help improve overall
performance. The DBA should weigh the issues for the affected
applications and decide whether the sweep interval provides the desired
database performance.
Tip: Unless the database contains many rolled back transactions,
changing the sweep interval has little effect on database size. As a
result, it is more common for a DBA to tune the database by disabling
sweeping and performing it at specific times. These activities are
described in the next two sections. </quote> definitely, since the
sweeping bug in IB5.5 was fixed, sweeping will not damage your data, but
frequent sweeping will only deliver overall improvement on only a
limited set of circumstances. It's not a belts-n-braces approach to be
taken on all ditributions. All too often, the backup/restore cycle at
the interval you are currently using will deliver, to your application,
the optimum performance available. Alan