Cumulative Sum or Dynamic Rank with New Function: Window, Offset, Index

[Fake_Meagron]

I am wondering if possible to calculate cumulative sum or dynamic rank with new function - Window, Offset, Index?
The trational way exhausts the CPU and memory and perform super slowly if data size is big.

Appreciate very much for any share. 

[Fake_Meagron]

@amitchandak 
Thank you so much, Amit!😃
Great job and super helpful! You figured out everything I need about Window,Offset,Index.

I'll mark this as solution.

[amitchandak · Accepted solution]

@Fake_Meagron , refer

Continue to explore Power BI Window function Rolling, Cumulative/Running Total, WTD, MTD, QTD, YTD, FYTD: https://youtu.be/nxc_IWl-tTc

Power BI Window function- Pareto Analysis, 80% of sales, Order by on Measure: https://www.youtube.com/watch?v=UVxiLc_AzSs

Power BI Index function: Top/Bottom Performer by name and value- https://youtu.be/HPhzzCwe10U

Power BI Offset Compare Categories, Time Intelligence MOM, QOQ, and YOY: https://youtu.be/5YMlkDNGr0U

Power BI Window function- TOP N% with Others: https://youtu.be/rQElaRoPbUA