Add SessionConfig reference to ScalarFunctionArgs

[alamb]

Is your feature request related to a problem or challenge?

• Now that Add ScalarUDFImpl::invoke_with_args to support passing the return type created for the udf instance #13290 is merged (thanks @joseph-isaacs) we have a place to add new

@Omega359 noted that by adding SessionConfig to the ScalarFunctionArgs unblock several tasks such as

• datafusion.execution.time_zone is not used for basic time zone inference #13212
• Make from_unixtime aware of execution timezone #12892
• Feedback request for providing configurable UDF functions #10744

Describe the solution you'd like

Add &SessionConfig to ScalarFunctionArgs, and ideally add a test that shows the config gets through.

Describe alternatives you've considered

No response

Additional context

We should try and get this done before DataFusion 44 is released so it isn't a breaking change

• Release DataFusion 44.0.0 #13334

[Omega359]

Well, small issue. ScalarFunctionArgs is in datafusion-expr which can't use SessionConfig directly since it's in datafusion-execution which depends on datafusion-expr which would cause a circular dependency. We can use ConfigOptions there which would give us access to all config except the opaque extensions in SessionConfig which I think is acceptable.

[niebayes]

Great work!

[Omega359]

Started delving into this trying to find a good way to impl. Trying to add config_options: ConfigOptions to ScalarFunctionExpr Having lots of fun with eq and hash with SessionConfig and f64 atm.

[alamb]

I wonder if we can use this trait: https://docs.rs/datafusion/latest/datafusion/catalog/trait.Session.html

[Omega359]

We could but it wouldn't solve the issue. The issue is PhysicalExpr requires implementations to impl Eq and Hash or to have implementations for DynEq and DynHash. That is fine until something like SessionConfig which doesn't is introduced. I am looking at updating the either the 'config_namespace' macro or add explicit implementations for 'ScalarFunctionExpr' to try and impl either of the above and use f64.to_bits() and f64::from_bits(..) to handle the problematic f64's in the config. I think it's possible