Re: reasons to separate indexes and data in different tablespaces
Date: Fri, 16 May 2008 17:45:19 -0500 (CDT)
Recoverability was also the reason for putting redo logs on a separate disks (mirrored by Oracle), archived logs on a separate disk and contols files on 3 (or at least 2) separate disks. Without Raid, a single disk failure caused a recovery situation and if your archive logs were on the same disk as data, you were toast.
The 28(?? or was it 22) disk layout came from Keven Loney's Oracle 7 Database Administration book. That's the one I first used to learn Oracle so I remember it well. That was the optimum that no one could really use and then there was a 17 disk layout and on down to a minimum of 5 disks I think.
> There are actually several very good reasons to separate them. The first
> and most important is recovery. If you lose an tablespace with only
> indexes, you can always re-create the indexes. If you lose a tablespace
> with both, you have a recovery involved.
> The next is manageability. Its just easier to manage things if you keep
> tables and indexes separate.
> The third reason is you may not know or have control of the underlying
> storage, but you should have control of the tablespace layouts.