{"action":"created","issue":{"url":"https://api.github.com/repos/ContinuumIO/blaze/issues/986","labels_url":"https://api.github.com/repos/ContinuumIO/blaze/issues/986/labels{/name}","comments_url":"https://api.github.com/repos/ContinuumIO/blaze/issues/986/comments","events_url":"https://api.github.com/repos/ContinuumIO/blaze/issues/986/events","html_url":"https://github.com/ContinuumIO/blaze/issues/986","id":60587988,"number":986,"title":"head() on HDFStore seems to try to load everything?","user":{"login":"michaelaye","id":69774,"avatar_url":"https://avatars.githubusercontent.com/u/69774?v=3","gravatar_id":"","url":"https://api.github.com/users/michaelaye","html_url":"https://github.com/michaelaye","followers_url":"https://api.github.com/users/michaelaye/followers","following_url":"https://api.github.com/users/michaelaye/following{/other_user}","gists_url":"https://api.github.com/users/michaelaye/gists{/gist_id}","starred_url":"https://api.github.com/users/michaelaye/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/michaelaye/subscriptions","organizations_url":"https://api.github.com/users/michaelaye/orgs","repos_url":"https://api.github.com/users/michaelaye/repos","events_url":"https://api.github.com/users/michaelaye/events{/privacy}","received_events_url":"https://api.github.com/users/michaelaye/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/ContinuumIO/blaze/labels/bug","name":"bug","color":"fc2929"}],"state":"open","locked":false,"assignee":null,"milestone":{"url":"https://api.github.com/repos/ContinuumIO/blaze/milestones/5","html_url":"https://github.com/ContinuumIO/blaze/milestones/Release%200.8","labels_url":"https://api.github.com/repos/ContinuumIO/blaze/milestones/5/labels","id":674669,"number":5,"title":"Release 0.8","description":"Bugfix / Documentation release","creator":{"login":"aterrel","id":30583,"avatar_url":"https://avatars.githubusercontent.com/u/30583?v=3","gravatar_id":"","url":"https://api.github.com/users/aterrel","html_url":"https://github.com/aterrel","followers_url":"https://api.github.com/users/aterrel/followers","following_url":"https://api.github.com/users/aterrel/following{/other_user}","gists_url":"https://api.github.com/users/aterrel/gists{/gist_id}","starred_url":"https://api.github.com/users/aterrel/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/aterrel/subscriptions","organizations_url":"https://api.github.com/users/aterrel/orgs","repos_url":"https://api.github.com/users/aterrel/repos","events_url":"https://api.github.com/users/aterrel/events{/privacy}","received_events_url":"https://api.github.com/users/aterrel/received_events","type":"User","site_admin":false},"open_issues":68,"closed_issues":25,"state":"open","created_at":"2014-05-29T20:55:03Z","updated_at":"2015-03-10T23:57:06Z","due_on":"2015-01-25T05:00:00Z","closed_at":null},"comments":10,"created_at":"2015-03-10T23:41:12Z","updated_at":"2015-03-11T01:16:57Z","closed_at":null,"body":"I am trying to learn how to work with blaze on a 12 GB pandas HDFStore file.\r\nAfter having learned that I need to use ' hdfstore://' in front of the filename because pandas uses a different format (could be mentioned a bit more prominent in the tutorials), I tried a `head()` call on the blaze.Data object. I was expecting that it stops loading the HDF file after some count like 10..30 rows but my memory monitor jumps up to 2 GB used fast, so apparently it tries to load everything?\r\nWouldn't it be a design goal of blaze to avoid loading everything, unless that's not possible (yet?) with pandas HDFStores?\r\nHere's the commands I used:\r\n```python\r\ndbfile = get_current_database_fname()\r\nimport blaze as bz\r\np4data = bz.Data( 'hdfstore://'+dbfile+'::df')\r\np4data.head()\r\n```\r\nI confirmed with a p4data.columns that all the content is recognized correctly:\r\n```python\r\np4data.columns\r\n['classification_id',\r\n 'created_at',\r\n 'image_id',\r\n 'image_name',\r\n 'image_url',\r\n 'user_name',\r\n 'marking',\r\n 'x_tile',\r\n 'y_tile',\r\n 'acquisition_date',\r\n 'local_mars_time',\r\n 'x',\r\n 'y',\r\n 'image_x',\r\n 'image_y',\r\n 'radius_1',\r\n 'radius_2',\r\n 'distance',\r\n 'angle',\r\n 'spread',\r\n 'version',\r\n 'user_agent']\r\n```\r\n\r\nAm I doing something wrong or is there an incompatibility?\r\n\r\nVersions:\r\nblaze: 0.7.2\r\npandas: '0.15.2-318-g549b72f'\r\n"},"comment":{"url":"https://api.github.com/repos/ContinuumIO/blaze/issues/comments/78182822","html_url":"https://github.com/ContinuumIO/blaze/issues/986#issuecomment-78182822","issue_url":"https://api.github.com/repos/ContinuumIO/blaze/issues/986","id":78182822,"user":{"login":"mrocklin","id":306380,"avatar_url":"https://avatars.githubusercontent.com/u/306380?v=3","gravatar_id":"","url":"https://api.github.com/users/mrocklin","html_url":"https://github.com/mrocklin","followers_url":"https://api.github.com/users/mrocklin/followers","following_url":"https://api.github.com/users/mrocklin/following{/other_user}","gists_url":"https://api.github.com/users/mrocklin/gists{/gist_id}","starred_url":"https://api.github.com/users/mrocklin/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mrocklin/subscriptions","organizations_url":"https://api.github.com/users/mrocklin/orgs","repos_url":"https://api.github.com/users/mrocklin/repos","events_url":"https://api.github.com/users/mrocklin/events{/privacy}","received_events_url":"https://api.github.com/users/mrocklin/received_events","type":"User","site_admin":false},"created_at":"2015-03-11T01:16:57Z","updated_at":"2015-03-11T01:16:57Z","body":"> I even don't know what odo is as it's not mentioned in any of the tutorials here.\r\n\r\nThank you for the reminder to update those tutorials when we do the next Blaze release."}}