Fletcher
50-Minute Talk
Having spent many months in confusion over trying to profile Postgres, and helping other in similarly situations, I now know some of the things that can horribly wrong when profiling and benchmarking.
In this talk, I will go through some of the more common and confusing things, so you don't have to develop all the same scars. Questions we'll explore include:
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How can a substantial optimization lead to benchmarks running substantially slower?
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Why can the order in which benchmarks are run matter?
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Why will a recently compiled binary often be slower than an older one?
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How can the weather influence benchmark results?
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Why is it harder to profile virtual machines?
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Why can a change that increased the percentage of missed branches improve performance?
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Can your SSD suffer from temporary exhaustion?
For each of the problems I'll present a way to at least work around the problem.
