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thisisausername's avatar
thisisausername
Helper II
6 years ago

Using incremental refresh with OData - slow

When I attempt to use Incremental Refresh with an OData source, I get the following error regarding query folding:   "Unable to confirm if the M query can be folder. It is not recommended to use in...
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v-lid-msft's avatar
v-lid-msft
Community Support
6 years ago

Hi thisisausername ,

 

Based on this document, IF you are not using composite models, data sources do not support SQL queries like flat files, blobs, web, and OData feeds typically do not support query folding. In cases where the filter is not supported by the datasource back-end, it cannot be pushed down. In such cases, the mashup engine compensates and applies the filter locally, which may require retrieving the full dataset from the data source. This can cause incremental refresh to be very slow, and the process can run out of resources either in the Power BI service or in the on-premises data gateway if used.

 

If unable to verify, a warning is displayed in the incremental refresh dialog when defining the incremental refresh policy. SQL based data sources such as SQL, Oracle, and Teradata can rely on this warning. Other data sources may be unable to verify without tracing queries. If Power BI Desktop is unable to confirm, the following warning is displayed.

 

If you are using composite models, incremental refresh is supported for SQL Server, Azure SQL Database, SQL Data Warehouse, Oracle, and Teradata data sources only.

 

Best regards,

Community Support Team _ Dong Li
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.

  • thisisausername's avatar
    thisisausername
    Helper II
    6 years ago

    Thanks both. I had indeed read that article - it mentions 'typically', how can I find out if my OData feed is/is not able to fold with Incremental Refresh?

    • v-lid-msft's avatar
      v-lid-msft
      Community Support
      6 years ago

      Hi thisisausername ,

       

      The easy way is to set a small incremental range and try to do a incremental refresh, if it supports Query Folder, it should take much less time than full-size refresh. But it should test carefully such as limit the total rows because the process may run out of resources either in the Power BI service or in the on-premises data gateway if it does not support Query Folder.

       

      Best regards,

      Community Support Team _ Dong Li
      If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.