html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/issues/5168#issuecomment-826022291,https://api.github.com/repos/pydata/xarray/issues/5168,826022291,MDEyOklzc3VlQ29tbWVudDgyNjAyMjI5MQ==,2448579,2021-04-24T02:44:34Z,2021-04-24T02:44:34Z,MEMBER,Related: #2801,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,859577556
https://github.com/pydata/xarray/issues/5168#issuecomment-821655160,https://api.github.com/repos/pydata/xarray/issues/5168,821655160,MDEyOklzc3VlQ29tbWVudDgyMTY1NTE2MA==,1053153,2021-04-16T22:38:08Z,2021-04-16T22:38:08Z,CONTRIBUTOR,It may run even deeper -- there seem to be several checks on dimension sizes that would need special casing.  Even simply doing a variable[dim] lookup fails! ,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,859577556
https://github.com/pydata/xarray/issues/5168#issuecomment-821241108,https://api.github.com/repos/pydata/xarray/issues/5168,821241108,MDEyOklzc3VlQ29tbWVudDgyMTI0MTEwOA==,5635139,2021-04-16T15:04:17Z,2021-04-16T17:43:22Z,MEMBER,~Currently xarray requires known dimension sizes. Unless anyone has any insight about its interaction with dask that I'm not familiar with?~ Edit: better informed views below,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,859577556
https://github.com/pydata/xarray/issues/5168#issuecomment-821294184,https://api.github.com/repos/pydata/xarray/issues/5168,821294184,MDEyOklzc3VlQ29tbWVudDgyMTI5NDE4NA==,2448579,2021-04-16T16:28:09Z,2021-04-16T16:28:09Z,MEMBER,"I'm not sure about writing to zarr but it seems possible to support nan-sized dimensions when unindexed. We could skip alignment when the dimension is nan-sized for all variables in an Xarray object. 

```
~/kitchen_sync/xarray/xarray/core/alignment.py in align(join, copy, indexes, exclude, fill_value, *objects)
    283         for dim in obj.dims:
    284             if dim not in exclude:
--> 285                 all_coords[dim].append(obj.coords[dim])
    286                 try:
    287                     index = obj.indexes[dim]
```

For alignment, it may be as easy as adding the name of the nan-sized dimension to `exclude`.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,859577556
https://github.com/pydata/xarray/issues/5168#issuecomment-821285344,https://api.github.com/repos/pydata/xarray/issues/5168,821285344,MDEyOklzc3VlQ29tbWVudDgyMTI4NTM0NA==,1053153,2021-04-16T16:13:09Z,2021-04-16T16:13:09Z,CONTRIBUTOR,"There seems to be some support, but now you have me worried.  I have a used xarray mainly for labelling, but not for much computation -- I'm dropping into dask because I need map_overlap.  

FWIW, calling `dask.compute(arr)` works with unknown chunk sizes, but now I see `arr.compute()` does not.  This fooled me into thinking I could use unknown chunk sizes.  Now I see that writing to zarr does not work, either.  This might torpedo my current design.

I see the `compute_chunk_sizes` method, but that seems to trigger computation.  I'm running on a dask cluster -- is there anything I can do to salvage the pattern `arr_with_nan_shape.to_dataset().to_zarr(compute=False)` (with our without xarray)?




","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,859577556
https://github.com/pydata/xarray/issues/5168#issuecomment-821258307,https://api.github.com/repos/pydata/xarray/issues/5168,821258307,MDEyOklzc3VlQ29tbWVudDgyMTI1ODMwNw==,14808389,2021-04-16T15:30:59Z,2021-04-16T15:30:59Z,MEMBER,this also came up in #4659 and dask/dask#6058. In #4659 we settled for computing the chunksizes for now since supporting unknown chunksizes seems like a bigger change.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,859577556