Is your feature request related to a problem or challenge? Please describe what you are trying to do.
The dictionary encoding can be inefficient for Parquet column data that has a lot of unique values.
To mitigate this, parquet-java implements fallback based on the evaluation of the size of plainly encoded data for the first data page versus its dictionary-based encoding: if compression is not achieved, the column encoder falls back to the plain encoding.
Describe the solution you'd like
Add an option to enable dictionary fallback decided on compression efficiency, with a possibility to extend it with other behaviors in the future.
Describe alternatives you've considered
Implement the heuristic without an option. Since the added computation has some cost, this may be undesirable for some applications. The new encoding behavior is also a substantial change, so it's better introduced through an option.
Is your feature request related to a problem or challenge? Please describe what you are trying to do.
The dictionary encoding can be inefficient for Parquet column data that has a lot of unique values.
To mitigate this, parquet-java implements fallback based on the evaluation of the size of plainly encoded data for the first data page versus its dictionary-based encoding: if compression is not achieved, the column encoder falls back to the plain encoding.
Describe the solution you'd like
Add an option to enable dictionary fallback decided on compression efficiency, with a possibility to extend it with other behaviors in the future.
Describe alternatives you've considered
Implement the heuristic without an option. Since the added computation has some cost, this may be undesirable for some applications. The new encoding behavior is also a substantial change, so it's better introduced through an option.