Re: How about tailredo?

Brian Peasland wrote:
> What is the use of this application? I already have Log Miner to show me
> the contents of the online redo log. Obviously, this is not in realtime
> like a "tail -f" is, but then why do I care? Do I really need to see the
> transactions scroll by. In many cases, they would be scrolling by too
> fast to read anyway. I have some databases that fill up a 1GB online
> redo log file in less than five minutes. Not to mention the resources
> now being utilized on your database server. LGWR is writing to the log
> group. Eventually, ARCn will read from it. And now there will be another
> process reading that file, while LGWR is writing to it?

Generally, when you tail -f on a log file without piping to a filter, you know the server is not busy. If it is, you're probably trying to filter on something specific and optionally take action on it, like this:

#Only check user Joe's activity on this web server tail -f access_log | grep ^123.45.67.89

#Email me immediately if Oracle has ORA-600 nohup tail -f alert_ORCL.log | nohup perl -nle 'system("mailx -s 'ORCL error' youremail < /dev/null") if /^ORA-00600/' &

Similarly, it's up to the user of the redotail utility to make a useful filter.

Attaching tail -f to a file (or redotail to an Oracle logfile) won't cause any contention on the filesystem. Since a long time ago, most if not all UNIX filesystems have adopted shared read locks. The overhead of tail -f on a file is negligible. Hopefully the same is true with OP's redotail. If not, Oracle may bundle this tool in a future version.

Yong Huang Received on Wed May 10 2006 - 22:50:20 CDT