Re: Archive Log continuity

R.B wrote:
> I had a situation where a database (9.2.0.3) which is running in archive log
> mode had to be restored (by restoring of the Unix files) from the previous
> night's cpio backup and the archive logs NOT applied i.e work was lost.
>
> Before I opened the database I ran 'archive log list' and found the 'Next
> log sequence to archive' and moved it (12496) and all subsequent logs to
> another location and then opened the database as below:
>
>
> SQL> archive log list
> Database log mode Archive Mode
> Automatic archival Enabled
> Archive destination /arch/FBSP
> Oldest online log sequence 12494
> Next log sequence to archive 12496
> Current log sequence 12496
>
> (moved 12496 and subsequent logs)
>
> SQL> alter database open;
>
> Database altered.
>
> SQL> alter system checkpoint;
>
> System altered.
>
> SQL> alter system switch logfile;
>
> System altered.
>
> The database came up and is running
>
> My questions is
>
> Shutting down the database does appear to perform an archivelog switch but I
> assume it checkpoints the database so that the save represents the
> 'complete' database save at that point in time. If this is the case then
> won't the archive logs be out of sync with the database and therefore would
> be of no further use, since data has been written to the database but not
> the archivelogs.

All a checkpoint does is to roll forward the database to a particular SCN according to redo log entries. It doesn't remove anything from the redo log, even after the data has been rolled forward. It only reads from the redo logs. In particular, it won't cause the redo logs to be out of sync with the data, or create any gap. So I guess I'm not fully understanding what you were trying to say.

Cheers,
Dave

  If this is the case then does it mean:
>
> 1) I can now longer use previous cold database backups and roll forward
> using the archivelogs (due to the gap in the middle)
>
> 2) Utilities like flashback queiries and logminer will not also be able to
> bridge the gap.
>
> Are these the correct assumptions or have gone badly wrong somewhere ?
>
> Thanks
>
>
Received on Wed Aug 06 2003 - 18:04:00 CDT