Is Profiler not accurate?

When viewing lectures ‘Response Time Degradation, part 1-3’ Norberto shows the Profiler output of 0ms for query even when sifting through more than 1 million records with no index. He then shows that the explain plan shows 356ms for the same query.

Why did Profiler say 0ms when explain plan says 356ms?

@ Barron_43628

The data shown in the Profiler will be controlled by the settings for setProfilingLevel() and --slowms. Also remember that the Profiler may be set to do a sample of slow queries, rather than all queries.

As I said in response to your other post, this is something you can test for yourself and work out when and why there might be a difference between what the Profiler shows and the values returned by explain(). FWIW, I assure you that you can work this out, and both are accurate and useful tools. :wink: Good luck.