Re: SQL Queries SLOW after Oracle 8i to 10g migration

Blue Crystal Solutions wrote:
> I have just migrated from Oracle 8i to Oracle 10g on a Windows 2003
> server. The server is of higher processing power. Several SQL Queries,
> some complex ones are very slow.
>
> Some SQL Queries run faster and some queries run slower.
> Some queries used to run in 6 minutes now take up to 6 hours. Some
> queries run faster.
> The indexes are exactly the same in both versions.
> What has changed in the optimizer when upgrading from 8i to 10G?
> What needs to be done for these queries? And why?

Interesting how you can take the time to post the exact same message twice but cannot find the time to trace the session or sessions running these queries or generate explain plans for these suspect queries. In the absence of query plans, session traces and the complete version numbers for the 8i database with which you started and the 10g database to which you migrated an answer your question is, at best, exceedingly difficult. And, it will be even less likely to receive an answer if you haven't any query plans from the 8i database, even with plans from 10g and the version information as there will be nothing available with which to compare previous query paths to current ones, making any attempt to find that which has changed impossible.

Asking such a question without providing necessary information is an exercise in futility requiring a crystal ball. As none are available here provide the requested information. We don't read minds and we can't divine answers from the ether.

David Fitzjarrell Received on Mon Aug 29 2005 - 22:08:12 CDT