Re: When are redo logs done being archived??

Neil Greene wrote:
>
> Bill Beaton wrote:
> >
> > In article <R.3242C2AF.5F02_at_laoc.shl.com>,
> > Neil Greene <ngreene_at_laoc.SHL.com> writes:
> > >Mark Jahnz wrote:
> > >> What's the best way to determine when archive process has completed the
> > >> copy from an online redo log to an archive log. The entries in
> > >> v$loghistory appear to show up as soon as the copy is initiated! Does
> > >> v$log do the same?
> > >Get the list of archive log files (lets call it FLIST), force an archive
> > >log switch (alter system switch logfile) and you now know that the file
> > >in $FLIST are complete.
> >
> > Actually, I don't find this absolutely true on systems that do full async
> > io. I've found that for our archive logs ... average size 55MB, the
> > prompt returns after 'alter systen switch logfile', and the last archive log
> > can be as low as 10MB. It can be several minutes before it has been
> > entirely flushed from the buffers and caches out to disk.
> >
> > I've put in a minimum wait 'sleep 1500' after such an operation before I
> > feel confident enough to perform an ORACLE shutdown and system reboot.
>
> How can this happen? If I have 10 archive logs, 1-9 which have
> completed writing and archive log 10 which is currently being written to
> (in this case your 10Mb archive log) and I force an archive log switch
> so that I now have archive logs 1-11, then hasn't archive log 10
> completed writing?? In which case since my list contains archive logs
> 1-10.

This is all true. ALTER SYSTEM SWITCH LOGFILE completes before the old log has been archived (as it says in the manual).

If you need to synchromise with the writing of the logfile use ALTER SYSTEM ARCHIVE LOG CURRENT. This does not complete until the writing of the archive log is complete. Received on Tue Oct 01 1996 - 00:00:00 CEST