Help us understand the problem. What is going on with this article?

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


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