pydata / pydata/xarray

open_mfdataset concat_dim chunk

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Description

open_mfdataset does not allow chunking along concat_dim.

As a result if specific chunking is sought along that dimension by the user it may be best not to pass chunks at the open_mfdataset stage and rechunk variables afterwards.
This would be the case for example if chunks are large across files but small within files:
https://github.com/apatlpo/lops-array/blob/master/sandbox/natl60_tseries_debug.ipynb

I believe this is difficult to anticipate for new users (like me).

Couldn't this be specified in the documentation of open_mfdataset?

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Research direction

Start with the open_mfdataset documentation and review the linked natl60_tseries_debug.ipynb example for the chunking scenario described. Document that chunking along concat_dim is not supported at this stage, explain when users should rechunk variables afterward, and verify the rendered documentation clearly reflects the behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
documentation
Issue type
Documentation
Difficulty
2/5
Estimated time
1-3 hours
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
62/100

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