Chapter 12 -- Managing SQL Server Transactions and Locks

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Chapter 12

Managing SQL Server Transactions and Locks

About This Chapter

SQL Server uses transactions and locks to ensure the consistency and integrity of each database, despite errors that might occur in the system. A transaction is a logical unit of work that consists of a series of statements, such as SELECT or UPDATE statements. Locks prevent conflicts so that users cannot read or modify data that other users are in the process of changing. Transactions use locking to prevent users from modifying data affected by transactions that have not been completed. This chapter introduces you to the fundamentals of transactions and locks and then describes how transactions and locks are used to process data modifications.

Before You Begin

To complete the lessons in this chapter, you must have:

• SQL Server 2000 Enterprise Edition installed on a Windows 2000 Server computer.
• The ability to log on to the Windows 2000 Server computer and to SQL Server as the Windows 2000 Administrator.
• Completed the exercises in Chapter 3, "Designing a SQL Server Database," Chapter 4, "Implementing SQL Server Databases and Tables," Chapter 5, "Implementing Data Integrity," and Chapter 7, "Managing and Manipulating Data."