Re: Current Redo got deleted
From: Hans Forbrich <fuzzy.graybeard_at_gmail.com>
Date: Mon, 23 Mar 2015 05:29:42 -0600
Message-ID: <550FF926.5020600_at_gmail.com>
On 22/03/2015 11:05 PM, Mladen Gogala (Redacted sender mgogala_at_yahoo.com for DMARC) wrote:
> Basically, duplex redo logs are software RAID.
With one major difference - RAID will efficiently remove all copies when directed to remove any copy, whereas multiplex requires additional effort (a second remove command) to remove the mirrors.
Date: Mon, 23 Mar 2015 05:29:42 -0600
Message-ID: <550FF926.5020600_at_gmail.com>
On 22/03/2015 11:05 PM, Mladen Gogala (Redacted sender mgogala_at_yahoo.com for DMARC) wrote:
> Basically, duplex redo logs are software RAID.
With one major difference - RAID will efficiently remove all copies when directed to remove any copy, whereas multiplex requires additional effort (a second remove command) to remove the mirrors.
In other words, duplexing logs can protect against specific human errors, the "rm -f {file}" that hardware or software raid can not protect against. (It does not necessarily protect against "rm -rf {tld}"
The risk of that happening and needing protection needs to be evaluated by the customer/admin team.
/Hans
-- http://www.freelists.org/webpage/oracle-lReceived on Mon Mar 23 2015 - 12:29:42 CET