{"action":"created","issue":{"url":"https://api.github.com/repos/HDFGroup/hdf-compass/issues/32","labels_url":"https://api.github.com/repos/HDFGroup/hdf-compass/issues/32/labels{/name}","comments_url":"https://api.github.com/repos/HDFGroup/hdf-compass/issues/32/comments","events_url":"https://api.github.com/repos/HDFGroup/hdf-compass/issues/32/events","html_url":"https://github.com/HDFGroup/hdf-compass/issues/32","id":71480810,"number":32,"title":"Poor performance with 4 dimensional datasets","user":{"login":"jreadey","id":7785492,"avatar_url":"https://avatars.githubusercontent.com/u/7785492?v=3","gravatar_id":"","url":"https://api.github.com/users/jreadey","html_url":"https://github.com/jreadey","followers_url":"https://api.github.com/users/jreadey/followers","following_url":"https://api.github.com/users/jreadey/following{/other_user}","gists_url":"https://api.github.com/users/jreadey/gists{/gist_id}","starred_url":"https://api.github.com/users/jreadey/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jreadey/subscriptions","organizations_url":"https://api.github.com/users/jreadey/orgs","repos_url":"https://api.github.com/users/jreadey/repos","events_url":"https://api.github.com/users/jreadey/events{/privacy}","received_events_url":"https://api.github.com/users/jreadey/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/HDFGroup/hdf-compass/labels/enhancement","name":"enhancement","color":"84b6eb"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-04-28T05:17:11Z","updated_at":"2015-04-28T18:14:05Z","closed_at":null,"body":"Viewing moderately sized 4-dimensional datasets is very slow.  E.g. ES_RealLW in: http://hdfgroup.s3.amazonaws.com/data/hdf5test/gz6_SCRIS_npp_d20140522_t0754579_e0802557_b13293__noaa_pop.h5 has a shape of (60, 30, 9, 717).  It's very hard to scroll through the dataset in the ArrayGrid on my MacBook Pro, 16GB ram."},"comment":{"url":"https://api.github.com/repos/HDFGroup/hdf-compass/issues/comments/97159526","html_url":"https://github.com/HDFGroup/hdf-compass/issues/32#issuecomment-97159526","issue_url":"https://api.github.com/repos/HDFGroup/hdf-compass/issues/32","id":97159526,"user":{"login":"andrewcollette","id":3101370,"avatar_url":"https://avatars.githubusercontent.com/u/3101370?v=3","gravatar_id":"","url":"https://api.github.com/users/andrewcollette","html_url":"https://github.com/andrewcollette","followers_url":"https://api.github.com/users/andrewcollette/followers","following_url":"https://api.github.com/users/andrewcollette/following{/other_user}","gists_url":"https://api.github.com/users/andrewcollette/gists{/gist_id}","starred_url":"https://api.github.com/users/andrewcollette/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/andrewcollette/subscriptions","organizations_url":"https://api.github.com/users/andrewcollette/orgs","repos_url":"https://api.github.com/users/andrewcollette/repos","events_url":"https://api.github.com/users/andrewcollette/events{/privacy}","received_events_url":"https://api.github.com/users/andrewcollette/received_events","type":"User","site_admin":false},"created_at":"2015-04-28T18:14:05Z","updated_at":"2015-04-28T18:14:05Z","body":"Yes, almost certainly chunking-related.  It's using 3 MB chunks, which are bigger than the 1M limit for internal HDF5 caching, plus using GZIP.\r\n\r\nProbably the best place to address this would be to add caching to the Array implementation in the HDF5 plugin.  We could make this a general recommendation: access to the last two dimensions of an Array node should be optimized by the plugin if possible, since that's what the GUI viewer uses."}}