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N + 1 問題

More than 3 years have passed since last update.

SQLクエリが 「データ量N + 1回 」走ってしまい、取得するデータが多くなるにつれて(Nの回数が増えるにつれて)パフォーマンスを低下させてしまう問題。

例えば、アソシエーションの 1 : n の関係の際にこの問題が生じる

参考
http://zephiransas.github.io/blog/2015/07/08/eager-load-with-paranoia/
http://ruby-rails.hatenadiary.com/entry/20141108/1415418367
http://www.techscore.com/blog/2012/12/25/rails%E3%83%A9%E3%82%A4%E3%83%96%E3%83%A9%E3%83%AA%E7%B4%B9%E4%BB%8B-n1%E5%95%8F%E9%A1%8C%E3%82%92%E6%A4%9C%E5%87%BA%E3%81%99%E3%82%8B%E3%80%8Cbullet%E3%80%8D/

nakki
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