Re: An ancient mystery
Is it a very complex query which joins with other tables hitting OPTIMIZER_MAX_PERMUTATIONS because the potential execution operations against *other* tables has changed (indexes dropped/created or statistics updated on any of the other tables in the query) ? 

At 11:05 AM Friday, Dennis Williams wrote:

List,

The situation:
Oracle <http://8.1.7.4>8.1.7.4 database on Solaris 8 (soon to be upgraded to 10g) 
Rule-based Optimizer
A query which has run for years using an indexed access to a very large table (maybe 100 million rows) suddenly decides to use a full-table scan, shutting down a critical business process. 

Then after several hours, it switches back to using the index.
All concerned claim that nothing changed before or after.
Needless to say the business users are nervous. They think maybe the database grew beyond some limit. 

Can anyone think of an explanation?

Thanks,
Dennis Williams



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