Xarray with Zarr encoding

[gmfarache]

Hello!

I recently started to use Xarray integrated with Dask arrays and Zarr format. I'm having trouble understanding the append option in the to_zarr method with the encoding option. The appending option enables us to write more data in an already disk-written file without reading it to memory, right?

So, when we try to append data in a compressed Zarr file it is not necessary to indicate the compression in the append execution? So, what I'm trying to understand is: when we append data in a compressed Zarr file, does the library already identify the compression and apply it in the append data? I tried to write an append data with the same compression of the zarr file and got the following error: ValueError: variable 'precipitation' already exists, but encoding was provided.

I have just one more question concerning appending data in Zarr files but with chunks. When I indicate the chunk sizes that I want in the append data it is applied to all data in the Zarr file or just to the appended one?