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.zmetadata clarification

Open DennisHeimbigner opened this issue 3 years ago • 3 comments

re: https://github.com/zarr-developers/zarr-python/pull/268

The .zmetadata object is needed to hold the consolidated meta-data. But as far as I can tell, the V2 spec does not mention this even as optional. Can someone point me to some revised version of the V2 spec that describes .zmetadata?

DennisHeimbigner avatar Apr 20 '21 19:04 DennisHeimbigner

@DennisHeimbigner: .zmetadata is currently outside of the v2 spec (i.e. an implementation detail) like dimension_separator was.

joshmoore avatar Apr 20 '21 21:04 joshmoore

@joshmoore

I have a question regarding this. So when we consolidate metadata with / dimension separator, it ends up writing the metadata file as zmetadata instead of .zmetadata; and the open_consolidated fails by default.

CORRECTION: approach 1 below doesn't work. It has to be the latter; but then the zmetadata file is not hidden and also users have to specify it every time they open it with open_consolidated.

We can alleviate this by consolidating metadata with a store that still has . as separator; or by providing the zmetadata name to open_consolidated. However, either solution is not very elegant.

What could be a possible solution to this? Should we wait until this becomes a standard in v3 for an elegant solution or is there some low-effort solution with current v2?

Thanks!

tasansal avatar Aug 15 '22 16:08 tasansal

is there some low-effort solution with current v2?

I think so, yes. This sounds very much like a straight-forward bug (thanks for opening as #1121). Somewhere there's a check for "." which needs to be made smarter.

joshmoore avatar Sep 06 '22 14:09 joshmoore

closing this now and cross referencing with the v3 todo list here: #1161

jhamman avatar Dec 07 '23 20:12 jhamman