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From Vladimir Ozerov <voze...@gridgain.com>
Subject Re: Query duration metrics
Date Tue, 28 Nov 2017 07:02:07 GMT
Hi Andrey,

You are right, current implementation of metrics is questionable. Please
feel free to file a ticket if you have ideas on how to improve it.

On Sun, Nov 5, 2017 at 11:17 PM, Andrey Kornev <andrewkornev@hotmail.com>

> Hi,
> It appears as if the query duration metric is a bit misleading.
> GridQueryProcessor.executeQuery() doesn't actually "run" the query. It
> simply delegates query execution to a closure passed in as a parameter. The
> closure may or may not actually execute the query. In some (all?) cases,
> the closure simply creates and returns an Iterable (how does
> IgniteH2Indexing.runQueryTwoStep, for example). Actual query execution
> happens at some point later when user instantiates an Iterator from the
> Iterable. What's in fact recorded (by GridQueryProcessor on line 2477) as
> the "query duration" is just the query parsing stage as well as some
> query's AST manipulation logic that tries to convert the regular regular
> query to a map/reduce style query. So, it's basically a "prepare statement
> duration" that is currently reported as "query duration".
> Am I missing something?
> Thanks
> Andrey

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