RE: maximum controlfile size and controlfile_record_keep_time

From: D'Hooge Freek <>
Date: Thu, 17 Sep 2009 13:56:31 +0200
Message-ID: <>


Not really an answer to your question, but I'm wondering how long you actually need the backup information in the controlfile? I mean, if you have the rman logs (which are backupped by the filesystem backup) and you have the autobackup controlfile enabled, then what is the use of having the information in the controlfile of 6 months old backup? Changes that you need to restore from that backup are very slim, but the information to do so is still availabe from the logfiles.

If you have several databases and you need to keep track of backup durations / sizes, then a rman repository seems (to me) more appropriate, then just using the controlfile.


Freek D'Hooge
Oracle Database Administrator
tel +32(0)3 451 23 82

From: [] On Behalf Of Niall Litchfield Sent: donderdag 17 september 2009 13:22
Subject: maximum controlfile size and controlfile_record_keep_time


Does anyone with large retention policies for rman backups on their systems have an indication of how many backup records I can reasonably expect to retain in a controlfile in addition to an RMAN catalog. I'm aware that a controlfile is limited to 20,000 blocks and that both backup and archivelog records get recorded here. I'm wondering at what sort of retention period a catalog really becomes necessary - i.e what sort of practical limits people have found before the control file cannot record the required backup information to meet their redundancy policies. I'm aware that transaction volume, backup frequency, #datafiles etc have a big impact. Any bugs people have run into with 20k block controlfiles would be well worth knowing as well. :(


Niall Litchfield
Oracle DBA
-- Received on Thu Sep 17 2009 - 06:56:31 CDT

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