Re: DB file not updated in ARCHIVELOG mode?

"Ortwin Glück" <glueck_at_freesurf.ch> wrote in message news:39B941D3.3E0B9B77_at_freesurf.ch...
> I have Oracle running in ARCHIVELOG mode (for backup reasons).
> I recognized that the modified date of the database file does not change
> unless i shutdown/startup the instance. In NOARHCIVE mode the modified
> date is changed on logfile switch. Archived Logfiles are created though.
 

> Is the data actually written to the DB file on logfile switch? Can I
> safely delete old archived logfiles without losing data?

Those two questions are important. (I'd say, depends on how old...) I answer below, please correct me if I bend the facts too much :-)

The database files are written to in a delayed manner ("when they have to") and not necessarily on a log switch. (Why having large enough redo log space is important).

The archived redo log files are copies of online log files (before online logs get reused). In a sense, a "trail" of changes made to the db. So if a disk crash occur, you would apply this trail of changes (archived log files from backup and/or disk) to a consistent set of database files, up to the last commited transaction.

Regards,
/Fad

>
> Ortwin Glueck
Received on Mon Sep 11 2000 - 18:15:04 CDT