8k block size upgrade

[vachaj]

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

[marist89]

fear, hope, afraid. These words alone should tell you about your course of action.

The obvious "WHY?" aside, you should test your queries on at least some kind of data to have an educated guess.

Personally, I think this is a very high risk operation. You're going to use exp/imp and rebuild your database, right? I would contemplate moving to 9i so I could use multiple block sizes.