MongoDB ODBC connector for PowerBI - Incremental refreshes are slow

[alt_RG]

Hi all,

We are using the Mongo DB ODBC connector for PowerBI to connect the MongoDB data source. We have implemented incremental refresh as per our data size is concerned. But after the initial refresh, 20-30K rows are pulled into the report in 11 mins on average. This is not what we are expecting. The refreshes are very slow. 

 I think query folding is also not happening in the Power Query at the first step where a simple SQL query is used to fetch the data from MongoDB through the ODBC connector.  Please help! Thanks for your suggestions. 

[alt_RG]

@lbendlin: I just found something in the Microsoft docs. It says, only the PostgreSQL connector supports query folding. No other connectors support query folding if you use a native database query.
I am unsure about this. 
Here is the link (https://docs.microsoft.com/en-us/power-query/native-database-query)

[lbendlin]

Note that query folding is not a hard requirement for incremental refresh. It is merely a preferred option. Incremental refresh will work with a source that doesn't fold.

[alt_RG]

Thanks, @lbendlin for your reply. I have tried what you said. But I am facing this error. I followed this video (https://www.youtube.com/watch?v=8hjdOCni_ZY)

[alt_RG]

@lbendlin, Can you please help me with this issue? 

[lbendlin]

Sorry, I don't have a MongoDB environment to play with.  Maybe someone else can test it out.

[lbendlin]

You are not actually doing an incremental refresh. Instead, you apply the RangeStart/RangeEnd filter over the full result set of your custom SQL query.

Move your SQL statement into the Power Query code (via Value.NativeQuery) and incorporate RangeStart and RangeEnd directly into that query.