Repository navigation
Convert BuiltInWindowFunction::{NthValue} to a user defined functions #12649
Description
Is your feature request related to a problem or challenge?
Part of #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
- 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
Describe alternatives you've considered
At a high level the process is:
- Add a new WindowUDFImpl in the
functions-windowcrate - Port the code from the relevant existing implementation of the the built in functions in datafusion/physical-expr/src/window
- Remove the
BuiltInWindowFunctionvariant and then get everything to compile (the compiler will show you where the existing implementations are)
Additional context
Here are some good examples:
- @jcsherin ported
RowNumberin Convert built-inrow_numberto user-defined window function #12030
Activity
alamb commentedon Sep 27, 2024
I think this one is also relatively straightforward and would make a good first project for someone skilled in Rust who wanted to get experience with the Datafusion codebase and tests
dharanad commentedon Sep 27, 2024
take
Omega359 commentedon Sep 28, 2024
Convert BuiltInScalarFunction::{NthValue} -> Convert BuiltInWindowFunction::{NthValue}
[-]Convert `BuiltInScalarFunction::{NthValue}` to a user defined functions[/-][+]Convert `BuiltInWindowFunction::{NthValue}` to a user defined functions[/+]alamb commentedon Sep 29, 2024
🤦 -- fixed
jatin510 commentedon Oct 21, 2024
Hi, @dharanad . If you are busy can I look into this !
dharanad commentedon Oct 21, 2024
Sure
buraksenn commentedon Oct 29, 2024
take