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Parallelism of query refresh RRS feed

Answers

  • I can't answer the question directly because what we get now is the emergent behavior from a number of simple interactions, not all of which are under our control. What I can tell you is this:

    1) No more than six evaluation processes will happen at the same time. If we get a request to evaluate something while six evaluations are already in progress, that request will block until one of the existing evaluations finishes. This is actually the source of a deadlock that some people have observed, so the behavior is slightly different in a future release.

    2) When loading directly into Excel sheets, Excel seems to start queries in parallel.

    3) When loading into the data model (i.e. PowerPivot), query execution appears to be serialized.

    I hope we'll be able to provide a more complete description at some point.

    Thursday, July 24, 2014 3:58 PM

All replies

  • I can't answer the question directly because what we get now is the emergent behavior from a number of simple interactions, not all of which are under our control. What I can tell you is this:

    1) No more than six evaluation processes will happen at the same time. If we get a request to evaluate something while six evaluations are already in progress, that request will block until one of the existing evaluations finishes. This is actually the source of a deadlock that some people have observed, so the behavior is slightly different in a future release.

    2) When loading directly into Excel sheets, Excel seems to start queries in parallel.

    3) When loading into the data model (i.e. PowerPivot), query execution appears to be serialized.

    I hope we'll be able to provide a more complete description at some point.

    Thursday, July 24, 2014 3:58 PM
  • Thanks Curt, that's very useful information.

    Regents,

    Chris


    Check out my MS BI blog I also do SSAS, PowerPivot, MDX and DAX consultancy and run public SQL Server and BI training courses in the UK

    Thursday, July 24, 2014 8:34 PM