When you generate a raw Oracle SQL Trace file you are faced with the arduous task of analyzing this trace file. Of course, TKPROF has always been there to help you with this analysis. This post is not about TKPROF, it is about another, lesser known, utility called Trace Analyzer, that is everything TKPROF is […]

In his latest article, Jonathan Lewis uses tkprof to analyse the performance of a query. He concluded that “When you examine the output from tkprof, it often takes a simultaneous cross-check of the block level statistics, the Row Source Operation counts, and some sensible guesswork about the purpose of the query, to be able to […]

While reading Mark Gurry’s OOW05 presentation (PDF), I noticed a simple yet an effective way to tune a query. Here is an example that demonstrates the trick.

If you use the Cost Based Optimizer (CBO) in your Oracle database, you may be surprised to know that decreasing the ‘COST’ of a query does not necessarily mean increased performance.