Optimizing sql server for import

[Anonymous]

Hi, does using columnar tables or columnwise indexes in sql server improve performance when importing data into pbi? Or only for directQuery?

[Anonymous]

Okay thanks 🙂

Just to clarify my question again: the setup is quite simple. Just import a table from sql server. Almost no power query except some casting of types. So, given that I am just querying "select * from table" i guess regular indexes should have no effect... (?). But will adding a columnstore index or changing the table to columnar help?

[Anonymous]

Thanks. I should specify that I am talking about the time it takes to import the data into the pbi model (Data refresh). Not the performance of the visuals..

[zoloturu]

@Anonymous 

I've covered both steps in my previous reply.

In more details, if you optimize querying of a source by implementing indexes (or setting proper data types, granularity etc.) then PowerQuery will load data faster.

You can also improve the speed by cleaning the PowerQuery code, sometimes it is not optimal or dirty.

Regards,
Ruslan Zolotukhin (zoloturu)
BI Engineer at Akvelon Inc. / Kharkiv Power BI User Group Leader / DAX & Power BI Trainer
-------------------------------------------------------------------
Did I answer your question? Mark my post as a solution!
It was useful? Press Thumbs Up!

You are from Ukraine? If yes then welcome to Power BI User Group - KhPUG website. Other country? Check and find proper one - Power BI User Groups

[zoloturu · Accepted solution]

Hi @Anonymous ,

In import mode Power BI query and load data to the xVelocity engine, then draw the digits on visuals. Columnar structure of SQL Server will help only at first step (query and load), but rendering of the visuals will take the same time if you will query a source with row storage.

Regards,
Ruslan Zolotukhin (zoloturu)
BI Engineer at Akvelon Inc. / Kharkiv Power BI User Group Leader / DAX & Power BI Trainer
-------------------------------------------------------------------
Did I answer your question? Mark my post as a solution!
It was useful? Press Thumbs Up!

You are from Ukraine? If yes then welcome to Power BI User Group - KhPUG website. Other country? Check and find proper one - Power BI User Groups

[dax]

Hi alekskr, 

I think the index in SQL server should work for both model, beacuse when data refresh, the model will query the data from datasource again. You could refer to A comprehensive guide to Power BI performance tuning  for details.

Best Regards,
Zoe Zhi

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