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The Real MTCS SQL Server 2008 Exam 70/432 Prep Kit- P58: Congratulations on your journey to become certified in SQL Server 2008. This book will help prepare you for your exam and give you a practical view of working with SQL Server 2008. | Maintaining Your Database Chapter 7 267 Table 7.1 Continued. DBCC Options FREEPROCCACHE Removes plans from the execution plan cache. SHRINKDATABASE Shrinks database files and log files for a database by a specified percentage. SHRINKFILE Shrinks database and log files. UPDATEUSAGE Shows and corrects page count and row count inaccuracies in catalog views. DBREINDEX Rebuilds indexes in a database. This option is deprecated and should be used for backwards compatibility only. INDEXDEFRAG Defragments indexes. This option is deprecated and should be used for backwards compatibility only. Other Statements Dllname FREE Frees the memory used by the specified extended stored procedure xp dll. FREESESSIONCACHE Flushes the distributed query cache for the current connection. FREESYSTEMCACHE Flushes all caches by releasing unused cache entries. Note that SQL Server cleans caches automatically in the background. HELP Shows the syntax for the specified DBCC command. TRACEON Enables trace flags used for diagnostic tracing. TRACEOFF Disables trace flags used for diagnostic tracing. Most DBCC commands do not affect the live database. Instead they are performed on a database snapshot. The snapshot is created used for the command and then dropped. Sometimes the snapshot cannot be created for example when the DBCC statement is run against the Master database. In this case the statement is executed against the actual database. Using the snapshot instead of the actual database avoids congestion or locking through the DBCC affecting your live environment. 268 Chapter 7 Maintaining Your Database However it is important to remember that most DBCC commands are processor intensive and should not be performed when the server is under a heavy load. Test Day Tip Don t spend a lot of time memorizing the syntax of every DBCC option. Instead perform the DBCC CHECKTABLE DBCC CHECKDB and DBCC SHRINKFILE examples to become familiar with more commonly used DBCC options. Some of the most powerful and .
