by Mohamed El Desouki [email protected] Tel :00966 553450836 جامعة سلمان بن عبد العزيز – السعودية – الخرج شرح مقرر نظم إدارة قواعد البيانات – محاضرات مباشرة Course : Database Management Systems – 2nd Database Course Topic 1 : Transaction Processing This video explain why concurrency control is needed in Database Management systems , it covers the following -What is concurrency control ? -Why concurrency control is needed ? -lost update problem , dirty read problem , unrepeatable read problem , incorrect summary problem.