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Joris Van den Bossche commented on ARROW-1983: ---------------------------------------------- > what would be desired the interface for writing and reading the dataset > metadata instances? For reading, I think the existing {{parquet.read_metadata}} is sufficient? (that already works with such metadata files generated by other libraries). For writing, the current {{parquet.write_metadata}} expects a pyarrow schema, so for that we indeed need a new method, or adapt the existing one to also accept a parquet FileMetaData object. But for writing, I think the main part that is missing is a way to combined the list of metadata objects into a single FileMetaData object? > [Python] Add ability to write parquet `_metadata` file > ------------------------------------------------------ > > Key: ARROW-1983 > URL: https://issues.apache.org/jira/browse/ARROW-1983 > Project: Apache Arrow > Issue Type: Improvement > Components: C++, Python > Reporter: Jim Crist > Priority: Major > Labels: beginner, parquet, pull-request-available > Fix For: 0.14.0 > > Time Spent: 5h 50m > Remaining Estimate: 0h > > Currently {{pyarrow.parquet}} can only write the {{_common_metadata}} file > (mostly just schema information). It would be useful to add the ability to > write a {{_metadata}} file as well. This should include information about > each row group in the dataset, including summary statistics. Having this > summary file would allow filtering of row groups without needing to access > each file beforehand. > This would require that the user is able to get the written RowGroups out of > a {{pyarrow.parquet.write_table}} call and then give these objects as a list > to new function that then passes them on as C++ objects to {{parquet-cpp}} > that generates the respective {{_metadata}} file. -- This message was sent by Atlassian JIRA (v7.6.3#76005)