Introduction to Database Systems

CHAPTER 9

INTRODUCTION TO TRANSACTION PROCESSING

After reading this chapter, the reader will understand:

• The four desirable properties of a transaction, which include atomicity, concurrency, isolation, and durability
• The various states that a transaction passes through during its execution
• Why the transactions are executed concurrently
• Anomalies due to interleaved execution of transactions
• The various possible schedules of executing transactions
• The concept of serializable schedules
• Different ways of defining schedule equivalence, which include result equivalence, conflict equivalence, and view equivalence
• Use of precedence graph in testing schedules for conflict serializability
• The recoverable and cascadeless schedules
• SQL transaction statements ...