RE: [GENERAL] vacuuming

At 15:31 +0300 on 1/7/98, Rob den Boer wrote:


> Why should I want  a backup when I never need it anyway???    ;-))

Oh, be serious. The frequency of dumps depends on the application in hand.
Not everybody wants to backup every day. We have an Oracle-based
application (yuck), which presents data derived from the main university's
database. The two databases are separate for security reasons. However,
this database needs no backup at all. If it's ruined, it will be recreated
by the end of the day anyway... The funny thing is that the Oracle admins
around here insisted on backing it up, thus rendering it unavailable to the
web for an hour a day - when it's totally unnecessary.

The moral of the story is that one should think intelligently about one's
backup policy. It's worth noticing in this context that backup and vacuum
frequencies both relate to the same thing - how fast things change in the
database. If there are updates all the time, inserts, deletes - you
probably need to update frequently. You also need to vacuum frequently!

Nevertheless, it's not a tight coupling. For example, if the things that
change rapidly are mostly temporary tables, or utility tables (used for
session management, for example), then you may still need to vacuum
frequently, to reclaim the space, but you wouldn't necessarily need to
backup as often.

Herouth

--
Herouth Maoz, Internet developer.
Open University of Israel - Telem project
http://telem.openu.ac.il/~herutma