A Part represents part of the source data. Eg a single file in a multi-file source, or a single table
in a multi-table source. Splitting sources into parts allows them to be read concurrently, therefore,
implementations must ensure that different parts can be safely read in parallel.
A single part is always read by a single thread.
A Part represents part of the source data. Eg a single file in a multi-file source, or a single table in a multi-table source. Splitting sources into parts allows them to be read concurrently, therefore, implementations must ensure that different parts can be safely read in parallel. A single part is always read by a single thread.