Re: Oracle archive mode and hot backups

From: Hemant K Chitale <>
Date: Mon, 31 Aug 2009 22:25:11 -0700 (PDT)
Message-ID: <>


Sometimes, "Senior and Very Experienced DBAs" jump to conclusions. From your post there isn't enough information to conclude that your DBA doesn't know backup and recovery and/or deserves to lose his job.

Let's look at some possibilities behind the DBA's action -- which he may not have disclosed to you :
1. The ArchiveLogDestination normally holds 4 days files (or 2 or 3 or 5 days). The daily backup *does* backup ArchiveLogs -- either of the last 24 hours or of the whole ArchiveLogDestination directory each time.
Therefore, it *is* safe to delete ArchiveLogs when the filesystem is more than 10GB full (provided that the deleted ArchiveLogs are at least older than the last backup run)

2. There is a background job to copy ArchiveLogs to another location periodically.

3. your database environment doesn't require PointInTimeRecovery but only RecoveryToLastBackup. As long as a Backup does include all ArchiveLogs (plus the OnlineRedoLog archived out) generated while the Database Backup was running the "RecoveryToLastBackup" is achievable even if older ArchiveLogs are periodically deleted. Yes, all those DBAs are going to jump in and say PointInTimeRecovery is what RMAN is about. RMAN is about Backups. RecoveryPoint and RecoveryObjectives are specified by Management -- whether the CEO or CIO. Some databases may not really need PointInTimeRecovery , but ArchiveLog is enabled to support Hot Backup !

4. The DBA is somewhat right in saying that the archivelogs are "not used". They aren't used in normal operations. They are *backedup *. They are used only for Recovery. As long as the DBA knows

  1. The ArchiveLogs *have* been backed-up OR
  2. The RecoveryPointObjective does not require those ArchiveLogs he does not have to preserve them.

Hemant K Chitale

On Aug 7, 5:35 am, Jeff Morgan <> wrote:
> We have an Oracle 10g database on UNIX moving to a new data center.
snip Received on Tue Sep 01 2009 - 00:25:11 CDT

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