Hi all,
I do not believe this question has been asked on here (apoloiges if it has).
I understand the benefits of using Indexed columns in a traditional database table to optimise the retrieval of data. For example, placing an Index on columns typically used for WHERE and JOIN clauses will aid the finding of row positions.
There is an option in Power Query to create an Index Column (Add Column > Index Column). However as far as I am aware all this does is create an additional, incremental column that will provide full unqiueness for the row in the Power Query dataset. The benefit I can see in this is that Power BI, is an aggregation engine will, by default, remove duplicates. By having this Index Column present and used in the aggregation the row shall show as unique and not be considered as a duplicate and therefore included in the calculation.
Clearly, the use of the term 'Index' in a traditional database sense and Power Query are different, and serve very different functions. The same will apply to creating an Index column using DAX. The use in Power Query and DAX is very different from an Index in a database.
Am I correct in my understanding?
Is there an Index function in Power Query or DAX that functions like a traditional database Index?
When should I use an Index Column (as described) in Power Query and DAX (other than the single reason I mentioned (i.e. to provide row uniqueness))?
Thanks in advance.
