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Re: Getting the execution time of a query
Posted by: Mike Lischke
Date: July 10, 2012 01:49AM

Bernard,

summing fetch time and execution time up into one value is simple and can be made at any time. Splitting both values if you just have one sum cannot.

The fetch time purely measures how it took to transfer the result, which has absolutely nothing to do with executing the query. The fetch time can even vary each time you run the query. Why should your network connection decide how good or bad your query is? Ok, one use actually exists: if the query returns too many data the transfer takes much longer. But even this is not entirely true, because sometimes results are cached, so they can be sent out quicker.

Performance tuning is not an easy area and relying only on the reported execution and fetch times might lead you to wrong conclusions.

Mike

Mike Lischke, MySQL Developer Tools
Oracle Corporation

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Re: Getting the execution time of a query
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