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Submitted

ODX Server: allow dirty reads

  • January 12, 2021
  • 6 replies
  • 3 views

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When source tables are heavily used and ODX Server performs a load, the process is very slow or may even fail.

Using Business Unit, we have the option to 'Allow Dirty Reads' to allow TX to read tables without locking them. This option lacks in ODX Server.

Currently we have to add all tables as a Managed Query, adding the WITH NOLOCK statement. Ticket #18989.

6 replies

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  • Known Participant
  • February 3, 2021

This is an issue with many ERPs that work through central transaction tables and expect other applications to work with read uncommitted isolation levels. Having this option is important.


  • Participating Frequently
  • February 12, 2021

Thanks for your product feedback.

We have passed your input to our R&D department for further evaluation.

The roadmap of our product is focused on a split in ODX, MSW, Semantic Layer and Customer Portal.

With that split we will see new features and functions appear that might exceed your expectations or make the request obsolete.


  • Participating Frequently
  • July 12, 2021

It would also be great if reading FROM the ODX was not blocked during import. In many cases it could be possible to skip waiting and return the last/previous full dataset.


  • Participating Frequently
  • July 12, 2021

@Steven: Can you please check if your request has been resolved by installing the latest version?

I found this in the release notes:

Fixed in ODX 20.10.21

  • 10782: Deadlock on executions from ODX
    Fixed potential deadlock issue when using an ODX SQL Storage and using the same database as the data warehouse database in the MDW.


  • Participating Frequently
  • July 12, 2021

Hi Alex, thanks. Do you know if we can update ODX without updating TX itself? We only have one ODX environment (production) and I'd love to update it but can't touch the TX server anytime soon.

NB: This is a general question, I don't believe that fix affects us since we are using ADLS gen 2 storage for the ODX. Here, there are no "dead"locks - just very long waiting periods if the ODX is doing an import. (Technically this would be a livelock)


  • Participating Frequently
  • July 12, 2021

@Steven: In general, the versions of ODX and TX should match, as there may be API version changes.

This fix will have no impact on the ADLS storage. I will pass your suggestion to R&D for review.