このTABLE定義であやういところはどこでしょう? サービスにどんなインシデントが発生したか想像できるでしょうか? CREATE TABLE reports ( id bigserial NOT NULL, user_id bigint NOT NULL, time_of_report timestamp without time zone NOT NULL, previous_report_id bigint REFERENCES reports (id), elapsed_time integer NOT NULL DEFAULT 0, CONSTRAINT reports_id_pkey PRIMARY KEY(id), CONSTRAINT reports_user_id_fkey FOREIGN KEY(user_id) REFERENCES users(id) MATCH SI
![PostgreSQLアンチパターン:外部キー制約の更新コストを見くびる - Qiita](https://cdn-ak-scissors.b.st-hatena.com/image/square/414b039c9fab5e06c0a5598f778e25055effc653/height=288;version=1;width=512/https%3A%2F%2Fqiita-user-contents.imgix.net%2Fhttps%253A%252F%252Fcdn.qiita.com%252Fassets%252Fpublic%252Farticle-ogp-background-412672c5f0600ab9a64263b751f1bc81.png%3Fixlib%3Drb-4.0.0%26w%3D1200%26mark64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-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%26mark-x%3D142%26mark-y%3D57%26blend64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZoPTc2Jnc9NzcwJnR4dD0lNDBtYXN1ZGFreiZ0eHQtY29sb3I9JTIzMjEyMTIxJnR4dC1mb250PUhpcmFnaW5vJTIwU2FucyUyMFc2JnR4dC1zaXplPTM2JnR4dC1hbGlnbj1sZWZ0JTJDdG9wJnM9NDFhMmMxYWJiYmIwOTRjMjBmYjhjNTc5ZTA3ZjRhZTE%26blend-x%3D142%26blend-y%3D486%26blend-mode%3Dnormal%26s%3Dcb7c6736effc0f47af994d9979c77669)