Potential performance issue: Unreliable performance of df.ewm in pandas 1.2.2

[TendouArisu]

Issue Description:

Hello.
I have discovered a performance degradation in the df.ewm function of pandas version 1.2.2 when ewm passed with times and it is so slow compared to ewm pased with int. And I notice that CI/requirements-wheel.txt, shows that it can depend on pandas version 1.2.2. I am not sure whether this performance problem in pandas will affect this repository. I found some discussions on GitHub related to this issue, including #39784 and #40072.
I also found that python/xorbits/_mars/dataframe/window/ewm/core.py used the influenced api. There may be more files used the influenced api.

Suggestion

I would recommend deleting the pandas 1.2.2 version.
Any other workarounds or solutions would be greatly appreciated.
Thank you!

[Dawnfz-Lenfeng]

Thank you for raising this concern about the pandas 1.2.2 performance issue with df.ewm.

The latest versions of Xorbits typically only support and are tested against the most recent pandas releases. We recommend users to upgrade to the latest stable version of pandas when using Xorbits.

The performance issue you mentioned in pandas 1.2.2 has been fixed in newer pandas versions. Since Xorbits is actively maintained and updated to work with current pandas releases, this historical issue should not affect current Xorbits users.

If you're experiencing any performance issues, please make sure you're using the latest versions of both Xorbits and pandas.

Thanks again for bringing this to our attention!