Parquet Statistics

[norberttech]

Parquet Writer is already collecting statistics, but it's not turning them into ColumnChunk statistics that can be later used by the Reader to reduce the number of partitions required to read when looking for specific data.

[norberttech]

DataPageV2 is also allowing to create statistics for a given data page, this might be useful for data page pruning while reading chunks which in case of very large datasets might bring significant performance improvements.