Re: Questions about Standby Database

> One problem I have experienced is the automatic copying of archive
> logs. On Windows NT it is actually possible to copying a file while
> the LGWR is still writing - resulting of course in an unusable file.
> My solution is to force a logswitch and wait a couple of minutes
> before copying. Furthermore I repeat the copying for the last few
> files of the former copy process.
>
> Not 100 % bulltproof, I admit, but even in a worst case the data loss
> will be minimal and I and my department can live with it.
>

Funny you should mention that. We have a working implementation of scripts that transfer/apply log files. This was one of the biggest things to overcome. Our solution is not perfect but works (UNIX AIX and Solaris). The file is first tested by fuser and the copy is allowed if it is clear. But the
file is not immediately removed, that's kind of important because if you remove the file while ARCH is writing it will either crash dragging the database down or disable itself.

A bullet-proof way to know the moment when to start copying is to check V$ARCHIVED_LOG or alert log file.

We now start copying the archived log file about a few seconds after the ARCH (not LGWR of course) finished writing it.

Regs
AK Received on Sun Oct 20 2002 - 01:42:30 CDT