Microsoft® SQL Server™ 2000 Programming by Example

Isolation Levels

In previous sections of this chapter, you learned about the concurrency problems experienced in a multiuser environment.

It is important to decide how changes from other connections can affect your results, or when to allow other connections to apply changes to the data you use in your connection.

You can select the isolation level of your transactions in SQL Server 2000 either per transaction or per table. You can use the SET ISOLATION LEVEL statement to specify the isolation level at the transaction level. To select the isolation level per table, you can use locking hints.

SQL Server 2000 supports four isolation levels:

• READ COMMITTED

• READ UNCOMMITTED

• REPEATABLE READ

• SERIALIZABLE

Isolation levels are defined to solve specific ...