Re: 8k block size upgrade concern

JeffV wrote:
> Hello All,
>
> Our team is currently quickly approaching an 8k block size upgrade of a
> fairly large production database (800 gig). This is one step in
> several to improve the performance of a long running (44 hour) batch
> cycle. My concern is the following and I hoping people can tell me
> why it shouldn't or shouldn't be a concern. We do not have a place at
> the moment where we can test this upgrade. My fear is that Oracle may
> in some cases alter the execution plans for the queries in our batch
> due to the new larger block size and make bad choices. I am afraid it
> may choose table scans instead of an index scan (as an example) at the
> wrong time and cause our batch to run much longer than normal. While
> we can resolve these issues, this happening in production the first
> time we run 8k would be a big issue. I might be able to deal with a
> problem here or there but several issues may cause us to not meet our
> service level agreement. Should I be concerned about this with an
> upgrade 4k to 8k? Should I cancel the upgrade for now? -- ORACLE 8i.
>
>
> Is there anything else I should stay up at night worry about with this
> upgrade?
>
> Thanks,
>
> Jeff Vacha

Without knowing the operating system and storage strategy no advice is possible other than to suggest you pay very special attention to two things previously said to you:

IANAL_VISTA
"Ready, Fire, AIM!"

Frank van Bortel
"your block size should match your Operating System Block Size!"

My take is that people who have not tested anything are just trying stuff because they can. Expect a very poor outcome. Chance rarely favors the ill-prepared.

-- 
Daniel A. Morgan
http://www.psoug.org
damorgan_at_x.washington.edu
(replace x with u to respond)