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 - QiitaCREATE 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 SIMPLE ON UPDATE NO ACTION ON DELETE CASCADE ); CREATE INDEX
