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/2004#issuecomment-396317995,https://api.github.com/repos/pydata/xarray/issues/2004,396317995,MDEyOklzc3VlQ29tbWVudDM5NjMxNzk5NQ==,579593,2018-06-11T17:16:43Z,2018-06-11T17:16:43Z,NONE,"netcdf-c master now includes the same mechanism for strided access of HDF5 files as h5py.  If netcdf4-python is linked against netcdf-c >= 4.6.2, performance for strided access should be greatly improved.","{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,307318224
https://github.com/pydata/xarray/issues/2004#issuecomment-375102231,https://api.github.com/repos/pydata/xarray/issues/2004,375102231,MDEyOklzc3VlQ29tbWVudDM3NTEwMjIzMQ==,579593,2018-03-21T21:29:34Z,2018-03-21T21:29:34Z,NONE,Confirmed that the slow performance of netcdf4-python on strided access is due to the way that netcdf-c calls HDF5.  There's now an issue on the netcdf-c issue tracker to implement fast strided access for HDF5 files (https://github.com/Unidata/netcdf-c/issues/908).,"{""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,307318224
https://github.com/pydata/xarray/issues/2004#issuecomment-375054212,https://api.github.com/repos/pydata/xarray/issues/2004,375054212,MDEyOklzc3VlQ29tbWVudDM3NTA1NDIxMg==,579593,2018-03-21T18:44:14Z,2018-03-21T18:44:14Z,NONE,"netcdf4-python does `reopened[::1, ::10]` by making a bunch of calls to the C lib routine `nc_get_vara`.  As pointed out in Unidata/netcdf4-python#680, this is faster than a single call to `nc_get_vars` (which does strided access, but is *very* slow).  Note that `reopened[::1, ::1][:,::10]` is very fast, but you have to have enough memory to hold the entire array.  I wonder how h5netcdf is reading the data - is it pulling the entire array into memory and then selecting or subset?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,307318224