Forum Discussion
Power Query Delete or Filter First can improve the performance?
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?
You should start with Removing the extra columns first and then perform Filtering and other operations in Power Query.
2 Replies
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.
You should start with Removing the extra columns first and then perform Filtering and other operations in Power Query.
