There is now no difference between "built in" / "prepackaged" scalar and aggregate functions in DataFusion, however there are still some "built in" window functions -- see the current source for BuiltInWindowFunction for the up to date list of what remains
The problem with having two different kinds of window functions is
There are some features that may not be available to User Defined Window Functions that rely on built in
Users can not easily choose which window functions to include or override the behavior if they need something different
Describe the solution you'd like
I would like to remove the "built in" version of this function and convert it to a user defined function
Is your feature request related to a problem or challenge?
Part of https://github.com/apache/datafusion/issues/8709
There is now no difference between "built in" / "prepackaged" scalar and aggregate functions in DataFusion, however there are still some "built in" window functions -- see the current source for BuiltInWindowFunction for the up to date list of what remains
The problem with having two different kinds of window functions is
Describe the solution you'd like
I would like to remove the "built in" version of this function and convert it to a user defined function
Describe alternatives you've considered
At a high level the process is:
Additional context
Here are some good examples: