tailieunhanh - Microsoft SQL Server 2008 R2 Unleashed- P76

Microsoft SQL Server 2008 R2 Unleashed- P76:SQL Server 2005 provided a number of significant new features and enhancements over what was available in SQL Server 2000. This is not too surprising considering there was a five-year gap between these major SQL Server 2008 is not as much of a quantum leap forward from SQL Server 2005 | 694 CHAPTER 22 Administering Policy-Based Management Execution Modes When you are implementing policies there are three types of execution modes. The On Change mode has two variations On Demand The On Demand policy ensures that a target or targets are in compliance. This task is invoked manually by right-clicking on the policy in the Management folder Policy Management folder Policy folder and selecting Evaluate. The policy is not enforced and is only verified against all targets that have been subscribed to that policy. You can evaluate a policy also by right-clicking on the database and selecting Policies and Evaluate. On Schedule Policies can be evaluated on a schedule. For example a policy can be scheduled to check all SQL Server 2008 systems once a day. If any anomalies arise these out-of-compliance policies are logged to a file. This file should be reviewed on a periodic basis. In addition whenever a policy fails the complete tree in SQL Server Management Studio displays a downward-pointing arrow next to the policy as shown in Figure . FIGURE SQL Server management tree illustrating failed policies for table name. On Change Prevent The On Change Prevent execution mode prevents changes to server server object database or database objects that would make them out of Download from Policy-Based Management Concepts 695 compliance. For example if you select a policy that restricts table names to only those that begin with the prefix tbl and you attempt to create a table called MyTable you get the following error message and your table is not be created Policy table name has been violated by Server local Database iFTS Table . This transaction will be rolled back. Policy description Additional help . Msg 3609 Level 16 State 1 Procedure sp_syspolicy_ dispatch_event Line 50 The transaction ended in the trigger. The batch has been aborted. On Change Log Only If you select On Change Log Only a policy condition that is evaluated as .