/// In this layout, the keys and values are each respectively contiguous. We do
/// not constrain the key and value types, so the application is responsible
/// for ensuring that the keys are hashable and unique. Whether the keys are sorted
/// may be set in the metadata for this field.
MapArray is not responsible for ensuring the uniqueness of keys. Therefore, we should ensure the keys are unique on the application side (DataFusion).
Describe the solution you'd like
We can check the keys are distinct when invoking the map and make_map functions.
Is your feature request related to a problem or challenge?
In most databases, the map type only allows unique keys. Refer to the behavior of DuckDB:
However, the specification of MapArray states:
MapArray is not responsible for ensuring the uniqueness of keys. Therefore, we should ensure the keys are unique on the application side (DataFusion).
Describe the solution you'd like
We can check the keys are distinct when invoking the
map
andmake_map
functions.Describe alternatives you've considered
No response
Additional context
No response