Redshift and data folding error

[DrBiker]

I am using a redshift database, and I can connect to that OK in Power BI Desktop.  My problem comes when I try to use some calculated fields; I have simplified some down to try and find the error so for example:

     Measure 2 = COUNT(evhc[flag]) 

Where flag is an integer.  This give the error:

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

I assume that when folding this query that Power BI is using SQL syntax rather than Redshift?

Is this a bug or am I missing something?

p.s. I know I can do this without using a measure, but this is a test as my measures are more complex than this.

[WaqasP]

Has this been resolved?

[pqian · Accepted solution]

@DrBiker I'm assuming you are connecting to RedShift in DirectQuery mode. This error is thrown when some aggregation (in this case the count) is been translated to M for execution, so it's not really SQL yet. 

I think this is related to a bug that we know about, is [flag] a nullable column? Counting on nullable column wasn't working in the preview bits, we will be fixing it in the next release.

[arify]

@pqian is right, this should be fixed in the next release (~end of august). Thanks

[sabedin]

Hi,

I am getting the same error message (although different DAX formula!!!

Is this fixed or not?

Thank you!

[MattAllington]

Redshift is in preview mode, so I guess it is a bug.    Send a frown using the desktop frown so the developers can look at it.