{"action":"created","issue":{"url":"https://api.github.com/repos/sequelize/sequelize/issues/3397","labels_url":"https://api.github.com/repos/sequelize/sequelize/issues/3397/labels{/name}","comments_url":"https://api.github.com/repos/sequelize/sequelize/issues/3397/comments","events_url":"https://api.github.com/repos/sequelize/sequelize/issues/3397/events","html_url":"https://github.com/sequelize/sequelize/issues/3397","id":63974345,"number":3397,"title":"Performance issues since version 2.0.3","user":{"login":"KTachyon","id":1596736,"avatar_url":"https://avatars.githubusercontent.com/u/1596736?v=3","gravatar_id":"","url":"https://api.github.com/users/KTachyon","html_url":"https://github.com/KTachyon","followers_url":"https://api.github.com/users/KTachyon/followers","following_url":"https://api.github.com/users/KTachyon/following{/other_user}","gists_url":"https://api.github.com/users/KTachyon/gists{/gist_id}","starred_url":"https://api.github.com/users/KTachyon/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/KTachyon/subscriptions","organizations_url":"https://api.github.com/users/KTachyon/orgs","repos_url":"https://api.github.com/users/KTachyon/repos","events_url":"https://api.github.com/users/KTachyon/events{/privacy}","received_events_url":"https://api.github.com/users/KTachyon/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":{"login":"janmeier","id":1210224,"avatar_url":"https://avatars.githubusercontent.com/u/1210224?v=3","gravatar_id":"","url":"https://api.github.com/users/janmeier","html_url":"https://github.com/janmeier","followers_url":"https://api.github.com/users/janmeier/followers","following_url":"https://api.github.com/users/janmeier/following{/other_user}","gists_url":"https://api.github.com/users/janmeier/gists{/gist_id}","starred_url":"https://api.github.com/users/janmeier/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/janmeier/subscriptions","organizations_url":"https://api.github.com/users/janmeier/orgs","repos_url":"https://api.github.com/users/janmeier/repos","events_url":"https://api.github.com/users/janmeier/events{/privacy}","received_events_url":"https://api.github.com/users/janmeier/received_events","type":"User","site_admin":false},"milestone":null,"comments":8,"created_at":"2015-03-24T11:38:46Z","updated_at":"2015-03-24T19:38:05Z","closed_at":null,"body":"I have noticed that since version 2.0.3 the performance of Sequelize has been hit a little bit hard for bigger queries. It doesn't seem to be a query de-optimisation issue, since both 2.0.2 and 2.0.3+ generate the same queries.\r\n\r\nAn example with a very noticeable performance hit:\r\n\r\n```javascript\r\nAModel.findAll({\r\n    where : {\r\n        column1: 'someString',\r\n        column2: [ /* around 300 UUIDs */ ]\r\n    }\r\n}, { transaction : transaction })\r\n```\r\n\r\nThis query, on 2.0.2, takes around 30ms, while on 2.0.3 through 2.0.5, takes around half a second."},"comment":{"url":"https://api.github.com/repos/sequelize/sequelize/issues/comments/85663327","html_url":"https://github.com/sequelize/sequelize/issues/3397#issuecomment-85663327","issue_url":"https://api.github.com/repos/sequelize/sequelize/issues/3397","id":85663327,"user":{"login":"mickhansen","id":699049,"avatar_url":"https://avatars.githubusercontent.com/u/699049?v=3","gravatar_id":"","url":"https://api.github.com/users/mickhansen","html_url":"https://github.com/mickhansen","followers_url":"https://api.github.com/users/mickhansen/followers","following_url":"https://api.github.com/users/mickhansen/following{/other_user}","gists_url":"https://api.github.com/users/mickhansen/gists{/gist_id}","starred_url":"https://api.github.com/users/mickhansen/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mickhansen/subscriptions","organizations_url":"https://api.github.com/users/mickhansen/orgs","repos_url":"https://api.github.com/users/mickhansen/repos","events_url":"https://api.github.com/users/mickhansen/events{/privacy}","received_events_url":"https://api.github.com/users/mickhansen/received_events","type":"User","site_admin":false},"created_at":"2015-03-24T19:38:05Z","updated_at":"2015-03-24T19:38:05Z","body":"That shouldn't matter for .map i'd think, but maybe it's hitting https://github.com/sequelize/sequelize/blob/9ebfb19fbaf4aeb9f514a348995b7c782bac4732/lib/utils.js#L206?"}}