Code reviewHardcr-g207

Subject DeadlockLevel Senior–Staff~32 minCommon in Databases & SQL · Concurrency interviewsIndustries Software development

Question

Review this SQL stored-procedure body (MySQL/InnoDB, REPEATABLE READ) that upserts a daily counter.

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Code to reviewsql

1START TRANSACTION;2 3SELECT count FROM daily_counters4  WHERE day = CURDATE() AND metric = p_metric5  FOR UPDATE;6 7-- if no row, insert it8INSERT INTO daily_counters (day, metric, count)9  VALUES (CURDATE(), p_metric, 1);10 11UPDATE daily_counters SET count = count + 112  WHERE day = CURDATE() AND metric = p_metric;13 14COMMIT;

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