Deprecate and eventually remove ScalarUDF::invoke_batch

[findepi]

ScalarUDF::invoke_batch is unused in production code.
The ScalarUDF::invoke_with_args is used instead

datafusion/datafusion/physical-expr/src/scalar_function.rs

Line 194 in faa8c1b

let output = self.fun.invoke_with_args(ScalarFunctionArgs {

ScalarUDF::invoke_batch should be deprecated and subsequently removed.

appropriate cleanup of ScalarUDFImpl interface is covered by #13515

[goldmedal]

I think this issue would be a nice good first-issue collection. The remaining functions are as below:

• array functions in datafusion/functions-nested/src
• core functions in datafusion/functions/src/core
• crypto function in datafusion/functions/src/crypto
• datetime function in datafusion/functions/src/datetime
• encoding function in datafusion/functions/src/encoding
• regex function in datafusion/functions/src/regex
• string function in datafusion/functions/src/string
• unicode function in datafusion/functions/src/unicode

After they are done, we can mark invoke_batch as deprecated formally.

[Blizzara]

Just FYI: As I note in #14729, it seems rust (neither compile nor clippy) doesn't warn about implementing a deprecated method, only calling it. As such, the eventual removal of invoke_batch will be a sudden compile-time break for anyone who's not manually checking changelogs.

I'm not saying it shouldn't be removed, I do think code needs to be able to evolve - just flagging this as it came as surprise to me :)

[goldmedal]

Just FYI: As I note in #14729, it seems rust (neither compile nor clippy) doesn't warn about implementing a deprecated method, only calling it. As such, the eventual removal of invoke_batch will be a sudden compile-time break for anyone who's not manually checking changelogs.

The deprecated flag of invoke_batch was removed by #13491 (comment). I'm not sure why we removed it 🤔. But I think we should add it back after all the sub-issues are done.