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/1823#issuecomment-531813935,https://api.github.com/repos/pydata/xarray/issues/1823,531813935,MDEyOklzc3VlQ29tbWVudDUzMTgxMzkzNQ==,1197350,2019-09-16T14:53:57Z,2019-09-16T14:53:57Z,MEMBER,"Is this issue really closed?!?

🎉🎂🏆🥇","{""total_count"": 1, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 1, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,288184220
https://github.com/pydata/xarray/issues/1823#issuecomment-489101053,https://api.github.com/repos/pydata/xarray/issues/1823,489101053,MDEyOklzc3VlQ29tbWVudDQ4OTEwMTA1Mw==,1197350,2019-05-03T13:47:12Z,2019-05-03T13:47:12Z,MEMBER,"So I think it is quite important to consider this issue together with #2697. An xml specification called [NCML](https://www.unidata.ucar.edu/software/thredds/current/netcdf-java/ncml/) already exists which tells software how to put together multiple netCDF files into a single virtual netcdf. We should leverage this existing spec as much as possible.

A realistic use case for me is that I have, say 1000 files of high-res model output, each with large coordinate variables, all generated from the same model run. If we want to  for for which we *know a priori* that certain coordinates (dimension coordinates or otherwise) are identical, we could save a lot of disk reads (the slow part of `open_mfdataset`) by never reading those coordinates at all. Enabling this would require a pretty low-level change in xarray. For example, we couldn't even rely on `open_dataset` in its current form to open files, because `open_dataset` eagerly loads all dimension coordinates into indexes. One way forward might be to create a new Store class.

For a catalog of tricks I use to optimize opening these sorts of big, complex, multi-file datasets (e.g. CMIP), check out
https://github.com/pangeo-data/esgf2xarray/blob/master/esgf2zarr/aggregate.py
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,288184220