changing rollback segment initial extent

From: Miller Ray (Softlab) <Ray.Miller_at_Softlab.co.uk>
Date: Wed, 30 Aug 2000 12:00:41 +0100
Message-ID: <9EC5A3A16E4BD41180730008C78432AC043155@birexb01.softlab.co.uk>

> Problem: I need to increase the initial extent of serveral existing
> rollback segments. Since I cannot alter the initial extent of an
> existing rollback segment, I plan to do the following:
>
> 1) offline the rollback segment
> 2) drop the rollback segment
> 3) create a new rollback segment having the same name as the old
> rollback segment and with new values for initial and next extents
> 4) online this new rollback segment
>

        That should work. You should look to be doing the work at a quiet time.

        You might also want to coalesce free space after deleteing each rollback segment to minimize fragmentation.

	Aim to create 20 extents in each segment initially
	Match the number of segments to the number of users (between 4

and 10 users to 1 segment), and make sure that the init.ora file reflects the number of segments if you want them online by default.

        Talk to oracle about using the optimal setting (works on some OSs and not on others apparently).

        Ray

--

Received on Wed Aug 30 2000 - 06:00:41 CDT