OLE DB or ODBC Error: [Expression.Error] We couldn't fold the expression to the data source.

[Anonymous]

I cannot get the most simplest measures or visuals to execute using Direct Queries with Redshift. An example query is getting the count of the primary key of a table while filtering on a column of type boolean. The measures/visuals work just fine through import.

Is this a known issue with the Redshift connector? Are there any workarounds to this issue? Is there an ETA on when a fix to this issue can be released? Help resolving this would be greatly appreciated.

Power BI Desktop Version: 2.66.5376.2521 64-bit (February, 2019)

[v-yuezhe-msft]

@Anonymous ,

I have contacted this issue internally, I will post back once I get any feedback.

Regards,
Lydia

[SamTrexler]

@v-yuezhe-msft , I am experiencing the same issue with the Amazon Redshift connector in Direct Query mode. Including any Text column in a visual causes this error - for a slicer, table or matrix visual. Number columns seem to work fine.

I am also using the Feburary 2019 Power BI Desktop, 64-bit.

[SamTrexler]

The problem still exists in 

Version: 2.67.5404.801 64-bit (March 2019)

[Anonymous]

@v-yuezhe-msft  I'm in the same boat, we have this same issue when working with Redshift in DirectQuery and it's frustrating.

[Anonymous]

We have the same issue here and I have the November 2019 update

[Anonymous]

Turned out that the data types used in Athena must be one of the supported data types in Redshift

https://docs.aws.amazon.com/redshift/latest/dg/c_Supported_data_types.html

Changing strings to varchar and integers to decimal data types got the direct queries working in Power BI against Redshift spectrum.

[rafaelruivo]

Hi youssef_youssef, I'm having the same issue here in November 2020, only number fields works in Redshift Spectrum -> Power BI. Can you elaborate on those string/varchar changes? 

[youssefyoussef]

Hi rafaelruivo,

I didn't have issues with Redshift Spectrum as long as you are sticking to the data type supported by Redshift. For strings, you need to define the columns as varchar or nvarchar in Athena/AWS Glue data catalog. string data type is not understood by redshift spectrum.