Subject RE: [firebird-support] over-sweeping??
Author Helen Borrie
At 10:18 AM 9/03/2004 +1100, you wrote:

>if that's correct, then, maybe the manual, which has had this information in
>it since I can remember (maybe 1994) should finally be corrected and have it

What it says in the manual (over which we have no control whatsoever!!) is
more or less correct in the context of automatic sweeps - at least the
piece you quoted. Someone who is doing 3 a.m. sweeps isn't talking about

My take on auto-sweeping is that the 20000 default sweep interval is going
to be a safety net for the neglectful DBA in the general case but that one
needs to get ones head around the whole housekeeping picture when deploying
-- especially into environments where nobody is monitoring the condition of
the database - and provide easy tools for the users to keep things going

I've encountered such deployments: the vendor has shipped the database
with the sweep interval set to 0 (because of misinterpreting the docs, in
many cases); and with applications that simply prevent any reasonable
garbage collection; where the only thing available to the users to fix
the outcome the (frequent) freezes and crashes is backup and restore (and
it is *scary* how often this is just "Backup" and "Restore", no
intermediate gbak -c).

With a DBMS that runs sweetly and doesn't need a SYSDBA on site, it's
tempting for developers to think *they* can treat the live database as a
black box and ignore the dynamic effects of changes in database
content. The real trick is do the right stuff in development so that the
users can treat it as a black box (more or long as they press the
right buttons on or near the right day)