Modification is sent by application to SQL Server Modification is sent by application to SQL Server 1 Data pages are located in, or read into the buffer cache and then modified Data pages are located in, or read into the buffer cache and then modified 2 Buffer Cache Modification is recorded in transaction log on disk 3 Later, checkpoint writes dirty pages to database Later, checkpoint writes dirty pages to database 4

Recovery ModelDescription SimpleDoes NOT permit transaction log (t-log) backups. Automatically truncates log to reduce space requirements FullRequires LOG BACKUPS to manage t-log space requirements. Avoids data loss if damaged or missing database file occurs. Permits point-in-time recovery. Bulk LoggedRequires log backups to manage t-log space requirements. Improves performance during bulk copy operations. Reduces t-log space usage by using minimal logging of operations.

Web Application 200GB Site Collections Project Sites Department Sites HR Sites Marketing Sites 750mb X 250 = 187,500mb / 1024 = 183gb 250

mdfldf Sunday Full Backup mdfldf Tuesday Differential mdfldf Differential Monday mdfldf Differential Wednesday You Lose mdf file of database on Thursday at 4:00pm (1) BACKUP LOG DB_Name TO D:\SQLBackups\TempBackup.Bak WITH NORECOVERY (4) RESTORE LOG FROM D:\SQLBackups\TempBackup.Bak BACKUP LOG DB_Name TO D:\SQLBackups\Weekly_T_Log.Bak WITH INIT

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