Hi, devs.
I'd like to start a discussion about to EncodingFormat and DecondingFormat provide copy API, which relate to FLINK-31686 [1]. Current, DecodingFormat doesn't support copy(), which makes the DecodingFormat resued after filter/projection is pushed down. The EncodingFormat has the same problem if class implements EncodingFormat#applyWritableMetadata(). So I think EncodingFormat and DecodingFormat need to provide a copy function, and it should be a deep copy if format implements DecodingFormat#applyReadableMetadata/EncodingFormat#applyWritableMetadata/BulkDecodingFormat#applyFilters. Looking forwards to your feedback. [1]: [https://issues.apache.org/jira/browse/FLINK-31686] Best regards, tanjialiang
