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https://issues.apache.org/jira/browse/ARROW-1983?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16853430#comment-16853430
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Rick Zamora commented on ARROW-1983:
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Right, I see what you are saying. You can pass in a list of files to
pq.ParquetDataset (obtained by calling read_metadata on the metadata file), but
the footer metadata will be unecessarily parsed a second time. For dask, this
is probably not much of an issue, because each worker will only be dealing with
a subset of the global dataset. In many other cases this is clearly
undesireable.
> [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: 6.5h
> 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.
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