A method or function to create Index column in data table view (non Transform data / Power Query mode)

I understand there is a very easy way to create an Index column through data transform in Power Query mode. But when dealing with large dataset (individual or multiple appended dataset) and having the Index column created in the data transform steps will lead to long data loading time.

Currently only able to locate RANK, RANKX function in DAX that can help create an Index column in Table view efficiently. But if user have only 1 data column that can only be referenced to create the Index column, there is a possibility of getting repeated / duplicate Index values with this function. Because this function is to provide data ranking after all.

Suggested idea is to either have a method or function to create an Index column in Table view efficiently.

Further understanding of this suggested request is based on a help request that I have posted in this community site.

https://community.fabric.microsoft.com/t5/Desktop/How-to-create-an-Index-column-with-random-repeated-column-data/m-p/3785052#M1225906