Christophe Noel (Spacebel)

> [@d-v-b](https://github.com/d-v-b) [@christophenoel](https://github.com/christophenoel), xarray do not allow this layout since it enforce data alignement The note you quoted applies inside a single Dataset (or DataTree node): all **data variables** within...

You're right for the datatree definition, but from what I read **Datatree** is the new abstraction that xarray introduced to represent a hierarchy of datasets. In xarray, you can: -...

> Why then the [xarray documentation](https://docs.xarray.dev/en/latest/user-guide/hierarchical-data.html#data-alignment) specifically says "datatree" and not "DataSet" knowing the [terminology](https://docs.xarray.dev/en/latest/user-guide/terminology.html) ? > > On the other hand, I am pretty sure to have ran into...

> I would be curious to hear more about how option A would break existing readers. Is the name of the dataset of particular important to readers, such that opening...

Let me nuance my previous comment. We are working in a democratic group, and while I defend the interests of my client (ESA), who initiated the GeoZarr effort, my voice...

I don’t think it’s paradoxical to call for backward compatibility. A specification that deliberately breaks alignment witthout a clear benefit with existing archives, risks becoming irrelevant to the very stakeholders...

just want to add that creating a completely new standard has been proposed in the past (including by myself), but after two years of discussion the conclusion was that we...

> Wouldn't a writer producing data for geozarr know in advance that there will be overviews? No. I expect in many cases the overviews are added afterward, even the "GeoZarr...

This use case is indeed usual but I would not consider it as an "overview case". It resembles the handling of Sentinel-2 data, where independent dataset exists for each resolution...

For multiscale support, I think we need a consensus that gives flexibility to data producers: >The multiscale group may include or exclude the native data, and the child zoom-level groups...