alamb commented on issue #252: URL: https://github.com/apache/arrow-rs/issues/252#issuecomment-834652617
Is this the behavior we want from the parquet writer? 1. The RecordBatch metadata `RecordBatch::metadata` is written by the parquet writer as `FileMetaData::key_value_metadata` https://github.com/sunchao/parquet-format-rs/blob/master/parquet.thrift#L1009 2. The Arrow field level metadata,`Field::metadata` is written by the parquet writer as `ColumnMetaData::key_value_metadata` https://github.com/sunchao/parquet-format-rs/blob/master/parquet.thrift#L730 What is the desired behavior when? 1. Different `RecordBatch`es are written to the parquet writer with different metadata? 2. Rows from a particular `RecordBatch` span multiple parquet row groups? (and thus there could be different field level metadata) Perhaps we could make the simplifying assumption and say "the arrow schema is supposed to be the same for all record, and thus we assume the metadata that applies to all the rows should be the same as well"? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
