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I have SQL Server 2019 Express Edition (CU8) on Windows Server 2019 (1809 version) and all of my queries go serial with NoParallelPlansInDesktopOrExpressEdition in NoparallelPlanReason property.

Is it that Express Edition never goes parallel? I cannot find anything about this in Microsoft documentation.

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  • what OS are you using?
    – Ronaldo
    Apr 16, 2021 at 10:38
  • @Ronaldo Windows Server 2019 (1809 version)
    – jericzech
    Apr 16, 2021 at 10:43

1 Answer 1

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The limitation is mentioned in the Query Processing Architecture Guide under the "Parallel Query Processing" section:

Parallel plans not supported for Desktop and Express edition.

The Editions and supported features of SQL Server 2019 (15.x) documentation says (under "Scale Limits") that Express is:

Limited to lesser of 1 socket or 4 cores

But that is just related to how many cores you can make available to the database engine. It doesn't say anything about parallel plans (other than a limitation related to batch mode operations being limited to 1 core on Express Edition).

All that to say that it looks like Express really doesn't allow parallel plans at all. I tried running queries on SQL Server 2019 and 2014 with the same NonParallelPlanReason given, so it doesn't appear to be a new limitation either.

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    Great and complete answer Josh. Many thanks. Hopefully this will spread the fact across the world :-)
    – jericzech
    Apr 16, 2021 at 11:38

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