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The Real MTCS SQL Server 2008 Exam 70/432 Prep Kit- P60: 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 7 277 Table 7.2 Continued. SQL Server 2008 Backup Types Backup Type Functionality Purpose Copy Only Same as the full backup however the copy-only backup does not mark the database as having been backed up. You cannot take differential backups based on a copy backup. Take an additional database backup without interfering with normal backup sequence. Transaction Log Back up all log entries since the last full backup. Multiple continuous log backups can be restored or replayed into a restore of a full backup bringing the database up-to-date. Perform a fast and efficient backup of all changes since the last full backup. Unlike differential backup you can restore or replay a log backup to a particular point-in-time. This allows you to roll back unwanted activity like malicious deletions. This also truncates the log file. Tail-Log Backup Backup of the transaction log performed just before a restore operation. If a database file is lost but the log file is still intact replaying the tail-log backup into the restored database allows you to bring the database up-to-date and eliminate the loss of transactions that occurred after the backup. Test Day Tip Study the various types of backup available and ensure that you understand the differences between them. Remember that although differential and transaction log backups are quicker to perform they take a longer time to be replayed into a restored database. On the other hand while backing up the entire database is time consuming restoring it as a whole is faster than replaying numerous differential and transaction log backups into an initial restored database. 278 Chapter 7 Maintaining Your Database Choosing a Database Backup Strategy Choosing the appropriate database backup strategy depends on your organization s individual business continuity requirements the size of your database and the amount of time allocated for backup operations. The data loss tolerance is a measure defining how much .
