Which data retrieval option is better from performance and best practices view

[m4xon]

Hello All,

I have a probably simple question for more advanced users. I create reports based on ssms views. Is it better to get the data to Power BI from that view and later populate it by for example Table.SelectColumns in Power Query to obtain necessary tables or it is better to create these additional tables based on SELECT from that view or maybe avoid using PowerQuery and use DAX only? I would be greatful for your feedback for less experience collegue. 

Summarizing we have following options:

1) Data_Source = Sql.Database("Server", "Database", [Query="SELECT * FROM [dbo].[dboView]"])
2) point 1 + Sql.Database("Server", "Database", [Query="SELECT [Column2], [Column5] FROM [dbo].[dboView]"]) (as many times as we need something)
3) point 1 + Table.SelectColumns ( Data_Source, {"Column2", "Column5"}) (as many times as we need something)

4) point 1 + DAX (as many times as we need something)

Thank you in advance

Max

[v-yanjiang-msft · Accepted solution]

Hi @m4xon ,

For performance:

Option2 is the best way, only select the columns needed from data source will save query time and memory.

For Practice:

Option3 and Option4 are the same, because DAX operation(delete columns) will also add a step in Power Query. If you maybe use other columns later, choose this way can help you modify steps in Power Query.

Best Regards,
Community Support Team _ kalyj

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