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https://issues.apache.org/jira/browse/ARROW-8244?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17068794#comment-17068794
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Joris Van den Bossche commented on ARROW-8244:
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Thanks for opening the issue [~rjzamora]
Agreed this is a problem, and I think we should at least also return the path
(so it can be fixed afterwards), or otherwise set it ourselves (optionally).
Regarding those different options: starting to also return the path together
with the metadata is not really backwards compatible, so we would need to add
additional keyword like `path_collector` in addition to `metadata_collector`.
For simply always populating the file path, that might depend on whether there
are other use cases for collecting this metadata (although I assume dask is the
main user of this keyword).
A github search turned up dask, cudf and spatialpandas as users of the
`metadata_collector` keyword. I assume `cudf` needs the same fix as dask. I
didn't check yet how it's used in spatialpandas.
I suppose optionally populating it is the safest, I am only doubtful that
having it optional behind a new keyword is actually useful (whether there are
use cases for not wanting to populate it).
> [Python][Parquet] Add `write_to_dataset` option to populate the "file_path"
> metadata fields
> -------------------------------------------------------------------------------------------
>
> Key: ARROW-8244
> URL: https://issues.apache.org/jira/browse/ARROW-8244
> Project: Apache Arrow
> Issue Type: Wish
> Components: Python
> Reporter: Rick Zamora
> Priority: Minor
> Labels: parquet
> Fix For: 0.17.0
>
>
> Prior to [dask#6023|[https://github.com/dask/dask/pull/6023]], Dask has been
> using the `write_to_dataset` API to write partitioned parquet datasets. This
> PR is switching to a (hopefully temporary) custom solution, because that API
> makes it difficult to populate the the "file_path" column-chunk metadata
> fields that are returned within the optional `metadata_collector` kwarg.
> Dask needs to set these fields correctly in order to generate a proper global
> `"_metadata"` file.
> Possible solutions to this problem:
> # Optionally populate the file-path fields within `write_to_dataset`
> # Always populate the file-path fields within `write_to_dataset`
> # Return the file paths for the data written within `write_to_dataset` (up
> to the user to manually populate the file-path fields)
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