[task#9512] move from_unixtime, now, current_date, current_time to da…

[Tangruilin]

…tafusion_functions

Which issue does this PR close?

Closes part of #9512.

Rationale for this change

What changes are included in this PR?

Are these changes tested?

Are there any user-facing changes?

[Tangruilin]

now, current_date, current_time need to get query_execution_start_time.

But Now I see there is no query_execution_start_time in ScalarUDFImpl
@alamb

[Tangruilin]

now, current_date, current_time need to get query_execution_start_time.

But Now I see there is no query_execution_start_time in ScalarUDFImpl @alamb

I Think ExecutionProps can be added into ScalarUDF.

[Tangruilin]

// TODO: add execution_props in ScalarUDF, so that we can get some params like query_execution_start_time
/// Create a physical expression of the UDF.
///
/// Arguments:
pub fn create_physical_expr(
    fun: &ScalarUDF,
    input_phy_exprs: &[Arc<dyn PhysicalExpr>],
    return_type: DataType,
) -> Result<Arc<dyn PhysicalExpr>> {
    Ok(Arc::new(ScalarFunctionExpr::new(
        fun.name(),
        fun.fun(),
        input_phy_exprs.to_vec(),
        return_type,
        fun.monotonicity()?,
        fun.signature().type_signature.supports_zero_argument(),
    )))
}

I think I can add execution_props in ScalarUDF, so that we can get some params like query_execution_start_time in next PR

how do you think of it?

[alamb]

how do you think of it?

I think we can use ScalarUdfImpl::simplify in this case: https://github.com/apache/arrow-datafusion/blob/b1d8082c6271e49c1de6e20002b853ca1503ffde/datafusion/expr/src/udf.rs#L373-L380

Specifically, the SimplifyInfo gets passed ExecutionProps https://github.com/apache/arrow-datafusion/blob/b1d8082c6271e49c1de6e20002b853ca1503ffde/datafusion/expr/src/simplify.rs#L39

Thus for a function like now(), that would look like

1. The simplify() call should rewrite now() to a ScalarValue::TimestampNano
2. The invoke() call should error with a "internal error"

Does that make sense?

[alamb]

(thank you for working on this, by the way @Tangruilin 🙏 )

[alamb]

Marking as draft as I think this PR is no longer waiting on feedback. Please mark it as ready for review when it is ready for another look

[Omega359]

Dup of #9537

[Tangruilin]

Marking as draft as I think this PR is no longer waiting on feedback. Please mark it as ready for review when it is ready for another look

Maybe you need to close this