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From Jacques Nadeau <jacq...@dremio.com>
Subject Re: Question about Fragment Stats start time
Date Thu, 16 Jun 2016 21:03:43 GMT
It has to do with fast schema. It doesn't matter when the start time is
called because all the fragments will execute right at the beginning of the
query and propagate a first "schema batch". You could possibly modify it to
be the start of the second batch time to get what you want. (This would
thus also make the gantt chart in the UI useful again, as it was before we
added fast schema.)

Jacques Nadeau
CTO and Co-Founder, Dremio

On Thu, Jun 16, 2016 at 11:29 AM, Abdel Hakim Deneche <adeneche@maprtech.com
> wrote:

> Hey all,
> In the query profile, fragment's start time is taken when the fragment is
> first initialized. For leaf fragments that's fine as they'll start running
> right away, but for intermediate/root fragment, a long time may pass before
> they effectively start running (submitted to the execution pool).
> Is there a specific reason we did it this way ? would it make sense to
> measure the start time when the fragment executor run method is called for
> the very first time ?
> Thanks
> --
> Abdelhakim Deneche
> Software Engineer
>   <http://www.mapr.com/>
> Now Available - Free Hadoop On-Demand Training
> <
> http://www.mapr.com/training?utm_source=Email&utm_medium=Signature&utm_campaign=Free%20available
> >

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