Toad World® Forums

Optimization differences between 6.2.1 and 7.0.0.445


#1

I optimized the same statement on the same database using both versions and found differences (significant) in the number of rewrites generated (for the same Optimization Intelligence Level) and also for the proposed best SQL rewrite.

Is there anything fundamentally different in the way 7’s optimization process is working ? I did notice it seems to process faster.

I have screenshots comparing the execution plans, optimization details and Resolution screens


#2

From version to version, we will enhance the engine or fix bugs found in previous version. However, in this version 7, we do not have any big changes in the engine part. Most of the works are on the bug fix of it so I would not expect to have a big different in the alternatives.

If you found the optimization results to be very different from the last release, then it would be a problem we need to address now during the beta. I would appreciate your raising this issue. Please send the screenshots you have through the Beta email address you can find under the Help | Support Bundle (this is a good place to report problem).

Thanks.

Message was edited by: alex.luk@quest.com


#3

There was a bug with the quota settings in version 6. In version 6, the quota was ignored and it continued to create more SQL alternatives when it reached the quota. The accounts for the possible large discrepancy that you see in the number of SQL alternatives generated between version 6 and version 7.