Re: Backup/Recovery (BR) question

On Thursday 20 November 2003 18:00, Oli Sennhauser wrote:
> Hello Robert
>
> >If you do // drop database "DB1" // the first database will drop,
> >though you might want to verify if it is really damaged.
>
> Oh sh....! It worked. Thanks. I am used to do the other way around (from
> oracle).
>
> Do you have any idea to my second question?
>
> Q2: New situation: Why is it not a good idea to backup the database
> files of a cluster incl. all c_log and x_log (log files last) to get a
> "physicaly hot backup".
> In principle it is the same situation like a server which is crashing
> (not a once but during some time). After restoring, it should do a redo
> and rollback automatically like after a crash. This methode (physical
> hot backup) would increas backup and restore times dramatically.
>

Essentially I think you're right, it should behave much like a crashing
server. The main reason why people don't recommend it is that (depending on
your os setup) there is the potential to lose data that has been commited but
not actually written to disk. Note that you shouldn't get corrupted data
from this, but in many cases losing data is just as bad so we don't recomend
it. If you really want to do this, you should really either shut down the
database or get LVM going.

Robert Treat
--
Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL