How measure based on DAX work on Direct Mode load in Power BI

[amsrivastava]

Hi Folks!!

I have a Power BI Report where I have used DIRECT MODE and connected to the SNOWFLAKE.

I have created MEASURES such as count, average etc by using DAX expression.

Query : 

1. Where does processing of DAX expression take place when load is DIRECT MODE.

i.e Let say, I have created a MEASURE using DAX and when i will use this MEASURE on any visual, then where does the processing of the DAX will take place, at SOURCE (SNOWFLAKE) or anywhere with in POWER BI.

2. How to change IMPORT MODE to DIRECT MODE in POWER BI DESKTOP REPORT.

Thanks

Amit Srivastava

[amsrivastava]

Hi @Anonymous ,

Please suggest whether my understanding is correct based on your input, highlighted in RED.

1. DAX is processed on AS engine, which is a process of power bi desktop.

This is because DAX expressions are not translated into SQL queries that can be executed by Snowflake. Instead, Power BI sends SQL queries to Snowflake to retrieve the data needed for the DAX calculations, and then performs the calculations locally. 

>> Does that mean, every time, DAX expression was called, it will bring the data from source and perform calculation at PBI level, if yes, how does it hold defination of DIRECT MODE storage in this case?

2. Conversion from import mode to direct query mode is not supported. You can re-get data and then connect to that data source in direct query mode. 

>>Does that mean, in order to convery Import to Direct, one need to deleta all the tables where mode need to change along with related table and re-create table with Direct Mode storage and re create all the data modelling, relationships, calculated measures and columns again.

Please suggest

Thanks

Amit Srivastava

[Anonymous · Accepted solution]

Hi @amsrivastava ,

1.When a DAX expression is called, it does not extract data from the source, it just sends a SQL query to the data source to retrieve the data needed for the DAX calculation.

2.Your understanding is correct.

Best Regards,

Neeko Tang

If this post  helps, then please consider Accept it as the solution  to help the other members find it more quickly. 

[Anonymous]

Hi @amsrivastava ,

1. DAX is processed on AS engine, which is a process of power bi desktop.

This is because DAX expressions are not translated into SQL queries that can be executed by Snowflake. Instead, Power BI sends SQL queries to Snowflake to retrieve the data needed for the DAX calculations, and then performs the calculations locally.
2. Conversion from import mode to direct query mode is not supported. You can re-get data and then connect to that data source in direct query mode.

Best Regards,

Neeko Tang

If this post  helps, then please consider Accept it as the solution  to help the other members find it more quickly.