Hello everyone,
I am trying to understand the negative impact of archivelog on a system. im trying to check if the offline logs generated by the archivelog consume much space on disk. if yes i want to know how much compared to datafiles etc!!!

Please can you get me an earliest reply ???thanks in anticipation.

Run a few queries on v$loghist to see how often you are switching logs. Multiply by the size of your logs, and you will have your disk usage.

Now run a few questions by the executives of your company. Namely how important is this data/ Does it need to be backed up at all? if it was lost, how much impact would that have on the company?

Weigh the two, and you may have your answer.

Dear sir thanks for your quick reply. I have another question.the archive log files,should i keep them forever?i mean can i purged them on a date basis according the hot backup im continously doing?Suppose my hot backup is as at 19 nov 07.can i purge the archive logs dated before19 nov 07 so as to solve the problem of disk space???

Thanks very much for your help.

You should keep the archive logs as long as you keep your hot backups. Archive logs are required to recover from most hot backups. That depends on your users, and their requirements for recovering their data. Some law firms may require backups to be around for several years. Most systems may only require backups be kept for 30 days.

In general it is a very good idea to run the database in archivelog mode. Should you ever need to recover data you will be happy to have archive logs. It will also allow you to roll back your database to any point in time in the past. It is good practice to backup the archive logs all along with the rest of your database. This way you will only have arch logs for 24 hours on the disk.

Best wishes: Peter

prsahe > and if we disable or desactive it and we scedule a daily backup of the database or we really need this?

> if we disable or desactive it and we scedule a daily backup of the database or we really need this?
yes

However if you are not running in archive log mode and only doing a cold (database down) backup each day and something happened, you will lose all data between the backup and the time of the failure.

Why do you have this idea of purging your archivelog files? If you have any ideas to disabling archive log mode or trying to purge archive logs, my advice is that you should completely wipe out this idea.

The best thing you should do is if you are running in a low disk or if you are running in IO bottlenecks, try using a SAS diskcontroller which is external to your normal database environment or try storing the backups to a NAS server.

In case you have decided to use archive log backups inside your database server itself and you really think purging would help you administer your database, purge those logs that were made before your full database backup (On your own risk)

Regards
Ashique