netarea upc Optimizing SQL Server 2005 Performance in .NET

Implementation upc a in .NET Optimizing SQL Server 2005 Performance

Figure 12-3 Symmetric key encryption requires separately exchanging both the key and the encrypted document

10-36

On a portable computer running on battery power, it is a good idea to configure the computer to shut down the monitor and hard disks or enter standby after a period of time to help conserve battery power. On desktop computers (or on por table computers running on AC power), you can also configure these options, but you should be aware of potential problems. Some display adapters respond unpredictably when turned off, and you often cannot restore the display by simply moving the mouse or pressing a key. Unfor tunately, the only way to recover when a display does not restore is to reset the computer. Also, many users become confused when they come back to their computer to find a blank screen. Often, their solution is to turn the computer off or reset it. Many computers also do not work well when they come out of standby or when the hard disk is powered down. Sometimes the computer will not come back at all, forcing you to reset the computer. Sometimes the computer will come out of standby, but running applications and open documents crash. Your best bet is usually to disable such power options when a computer is plugged in by selecting the Never option on the Turn Off Monitor, Turn Off Hard Disks, System Standby, and System Hibernates drop-down lists. You can view and modify the way that a computer works when a battery is close to running out of power by using the Alarms tab, shown in Figure 7-11. You can config ure low battery and critical battery alarm levels and actions for each. Actions include sounding an alarm, displaying a message, forcing the computer into standby or shut ting it down, and running a program (useful for custom programs that log problems or send status alerts).

In addition to returning the results from a single SQL statement, you can use a Command object and DataReader to return the results of multiple SQL statements. To execute more than one SQL statement, set the CommandText property of a Command object to multiple SQL statements separated by semicolons (;). After calling the ExecuteReader method, the DataReader will hold the number of result sets equal to the number of SQL statements executed. To access the data returned by the additional statements, call the NextResult method of the DataReader.

Table 1-2

The following questions are intended to reinforce key information presented in this lesson. If you are unable to answer a question, review the lesson materials and try the question again. You can find answers to the questions in the Questions and Answers section at the end of this chapter. 1. A Windows XP Professional user reports that she is unable to access the Add/ Remove Programs icon in Control Panel. What is most likely the problem A. The Windows XP installation is corrupt. B. A Group Policy setting is in place that prevents access. C. The antivirus program is restricting access.

9

1. 2.

Figure 6-10

Objective 1.3 Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-29

CustomersDataGridView.Columns.Remove("LocationColumn")