Forum Discussion
Remove Duplicates creating a copy not filtering source
I have a large source data set and am attempting to extract a unique sub-set of data. All the instructions I've read reference the same instructions making a duplicate of the source table with reference, removing unnecessary columns and removing duplicate rows. Every time a change is made in subsequent steps, power query re-reads the original source file.
My goal is for the distince sub-set to only contain the distinct rows, not a filtered sub-set. For example, if I have 500,000 transactions in the original data set and select 3 columns for a dimension with 100 distinct records, I expect the dimension table to only have 100 rows and subsequent changes will only evaluate 100 records, not the orginal 500,000.
A dimension table should be additive and full scans should not be necessary of the orginating dataset every time a subsequent metadata change is made.
I would actually duplicate the table instead of referencing it. This way it goes through the same logic, but is a separate query. Then you can make your distinct table that does not force the other table to evaluate. You might also wish to disable loading of the original query, if you are using it in other queries.
--Nate
2 Replies
Anonymous
You can just create a table visual with only required data by using filters, slicer or other features in power bi. Then you should able to export the summarized data only.Export data from a Power BI visualization - Power BI | Microsoft Docs
Paul Zheng _ Community Support Team
If this post helps, please Accept it as the solution to help the other members find it more quickly.I would actually duplicate the table instead of referencing it. This way it goes through the same logic, but is a separate query. Then you can make your distinct table that does not force the other table to evaluate. You might also wish to disable loading of the original query, if you are using it in other queries.
--Nate