Power Query Delete or Filter First can improve the performance?

[KH_Mike]

Hi All,

I have a stupid question want to know. Right now, I concern to the Azure to get the table and it contain more than 100 columns. I need to filter certain field to get the data I need. Also, some column which are useless for me I will delete it as well.

Should I do the filtering in Power Query first or delete those unless column first in order to improve the loading performance?

[Vijay_A_Verma]

The operation which leads to reducation in size of rectangle ( i.e. grid of rows and columns) that should be done first. 

Hence, if your data size is 10 rows and 6 columns, then there are 60 cells.

Scenario 1 - If you delete 2 columns, then rectangle size would be 10*4 = 40 cells.

Scenario 2 - If you are able to filter out 4 rows, then rectanble size would be 6*6 = 36 cells 

Hence, in this case 2nd scenario is more beneficial. 

Key rule is that you should do both i.e. reduce columns and reduce rows. Hence, if I am able to delete 2 columns and filter out 4 rows, my rectangle size would be 6*4 = 24 cells.

Now, reduce as much as possible before bringing the data to PQ. If not possible, after bringing the data to PQ, use above principles.

[AnamPatel · Accepted solution]

You should start with Removing the extra columns first and then perform Filtering and other operations in Power Query.