Is your feature request related to a problem or challenge?
Deprecate is_nullable as the same information is already encoded by the field from return_field
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/// What type will be returned by this function, given the arguments? |
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/// |
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/// By default, this function calls [`Self::return_type`] with the |
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/// types of each argument. |
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/// |
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/// # Notes |
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/// |
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/// Most UDFs should implement [`Self::return_type`] and not this |
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/// function as the output type for most functions only depends on the types |
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/// of their inputs (e.g. `sum(f64)` is always `f64`). |
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/// |
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/// This function can be used for more advanced cases such as: |
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/// |
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/// 1. specifying nullability |
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/// 2. return types based on the **values** of the arguments (rather than |
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/// their **types**. |
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/// 3. return types based on metadata within the fields of the inputs |
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fn return_field(&self, arg_fields: &[FieldRef]) -> Result<FieldRef> { |
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udaf_default_return_field(self, arg_fields) |
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} |
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/// Whether the aggregate function is nullable. |
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/// |
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/// Nullable means that the function could return `null` for any inputs. |
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/// For example, aggregate functions like `COUNT` always return a non null value |
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/// but others like `MIN` will return `NULL` if there is nullable input. |
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/// Note that if the function is declared as *not* nullable, make sure the [`AggregateUDFImpl::default_value`] is `non-null` |
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fn is_nullable(&self) -> bool { |
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true |
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} |
Describe the solution you'd like
Similar to how we did for scalar UDFs: #17074
Describe alternatives you've considered
No response
Additional context
No response
