Re: Oracle7 performance problem

In article <1994Feb11.171022.29656_at_newshost.lanl.gov>, ronk_at_beta.lanl.gov (Ronald John Krantz) writes:
> We are seeing a significant performance drop while running a specific
> application on Oracle7 as compared to Oracle v6. A SQL select statement
> that requires 10 seconds on v6 requires well over 3 minutes on Oracle7.
> Although we have many other forms and reports that have excellent
> Oracle7 performance values, the troubling SQL statement is used in many
> reports and is forcing this application to return to v6 until the problem
> is diagnosed.
>
Have you run EXPLAIN PLAN on the statement under both ORACLE6 and ORACLE7?

The optimizer changed drastically in ORACLE7. We noticed a couple of situations where the same statement would optimize differently under the two versions.

We would modify those statements so that they would return the same results, but would use a more efficient access path. ORACLE7 'hints' are one way that you could do that.

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Bob Swisshelm                | swisshelm_at_Lilly.com     | 317 276 5472
Eli Lilly and Company        | Lilly Corporate Center  | Indianapolis, IN 46285