title: Use of compaction for Parquet bulk format
body: <p>Since version 1.15 of Apache Flink you can use the compaction feature to merge several files into one.
  <a href="https://nightlies.apache.org/flink/flink-docs-master/docs/connectors/datastream/filesystem/#compaction" rel="nofollow noreferrer">https://nightlies.apache.org/flink/flink-docs-master/docs/connectors/datastream/filesystem/#compaction</a></p>
  <p>How can we use compaction with bulk Parquet format?
  The existing implementations for the RecordWiseFileCompactor.Reader (DecoderBasedReader and ImputFormatBasedReader) do not seem suitable for Parquet.</p>
  <p>Furthermore we can not find any example for compacting Parquet or other bulk formats.</p>