Better support for nested data structures in Parquet format

Why it matters

This feature enhances ClickHouse's ability to correctly read and write nested data types (such as arrays, tuples, and nested structs) in Parquet files, addressing limitations in handling complex hierarchical data. It enables users to seamlessly integrate and process nested Parquet data more accurately and efficiently.

How to use it

Use the improved Parquet format support transparently when importing or exporting data involving nested structures. No special configuration is required; simply read or write Parquet files containing nested data using standard ClickHouse commands like SELECT or INSERT INTO with the Parquet format.