{"action":"created","issue":{"url":"https://api.github.com/repos/ContinuumIO/dask/issues/319","labels_url":"https://api.github.com/repos/ContinuumIO/dask/issues/319/labels{/name}","comments_url":"https://api.github.com/repos/ContinuumIO/dask/issues/319/comments","events_url":"https://api.github.com/repos/ContinuumIO/dask/issues/319/events","html_url":"https://github.com/ContinuumIO/dask/issues/319","id":88886757,"number":319,"title":"dask.dataframe.join","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},"labels":[{"url":"https://api.github.com/repos/ContinuumIO/dask/labels/enhancement","name":"enhancement","color":"84b6eb"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":2,"created_at":"2015-06-17T01:55:55Z","updated_at":"2015-06-18T05:53:18Z","closed_at":null,"body":"DataFrame joins can take on a few forms based on how much we know about the left and right sides\r\n\r\n* dask-pandas and pandas-dask: This is a trivial `map_blocks` operation\r\n* dask-dask along index with known partitions:  In this case we can compute joins very efficiently by cross referencing the partitions and only joining those blocks where we know that there is some intersection\r\n* dask-dask without known partitions:  When we join along a non-index column or when we don't know partitions, then we resort to a hash-join, probably using the shuffle mechanisms and `partd`\r\n\r\nI plan to take this on (unless someone else feels adventurous.)"},"comment":{"url":"https://api.github.com/repos/ContinuumIO/dask/issues/comments/113045266","html_url":"https://github.com/ContinuumIO/dask/issues/319#issuecomment-113045266","issue_url":"https://api.github.com/repos/ContinuumIO/dask/issues/319","id":113045266,"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":"2015-06-18T05:53:18Z","updated_at":"2015-06-18T05:53:18Z","body":"That would indeed be very interesting.  I'd also be interested in comparing against kdb partitioned tables."}}