1. 1 Chapter Overview Understanding Data Restoration Issues Understanding the Types of Database Backups Understanding the Restoration Process

2. 2 Data Restoration Goals Provide fault tolerance where possible. Monitor for problems before they occur. Plan for all forms of disasters. Determine acceptable data restoration times for each type of disaster. Quickly verify proper database functionality.

3. 3 Types of Data Backups Full database backupDifferential database backup Filegroup (or file) backup Differential filegroup (or file) backup Transaction log backupSnapshot backup technology

4. 4 Types of Data Restorations Full database restore Filegroup (or file) restore with full recovery Recovery to a point in timeRecovery to a named transaction

5. 5 Databases to Back Up Applicable user databases The master system database The msdb system database The model system database, if this database has been customized The distribution system database, if replication is being used

6. 6 Components of a Data Restoration Plan Document the entire system. Document the backup plan. Automate backups. Test the backup plan. Store backup media securely. Determine how long to retain backups.

7. 7 Full Database Backups Complete copy of a database as of the end of the backup. Online backup with only a small impact on performance. Either a full database backup or a backup of all filegroups is the starting point for a database restoration. Perform after initial population of the database and periodically thereafter.

8. 8 Differential Database Backups Complete copy of all database changes since the last full database backup Records only the most recent change Length of time required proportional to the number of modified extents Generally uses significantly less space than a full database backup Use with medium to large databases between full database backups

9. 9 File and Filegroup Backups F08vl01.FH8

10. 10 Differential File and Filegroup Backups Complete copy of all changes in file or filegroup since the last full file or filegroup backup Conceptually the same as differential database backups Use to back up frequently changing tables in between full file or filegroup backups

11. 11 Transaction Log Backups Sequential record of changes since the last transaction log backup. At the end of a transaction log backup, all VLFs containing inactive portions of the transaction log are truncated. Time and space required depends on frequency of changes to the database and frequency of transaction log backups. Frequency of transaction log backups depends on several factors.

12. 12 Full Database Backup Strategy

13. 13 Full Database and Transaction Log Backup Strategy F08vl03.FH8

14. 14 Differential Backup Strategy

15. 15 Database File or Filegroup Backup Strategy

16. 16 Automatic Recovery Process

17. 17 Recovery Process Using a Full Database Backup

18. 18 Recovery Process Using Filegroup (or File) Backups

19. 19 Restoration and Recovery to Another Point in Time

20. 20 Recovery Scenarios A user database data disk failure A user database transaction log disk failure A master database disk failure

21. 21 Chapter Summary Develop, document, and test a data restoration strategy that anticipates all forms of disasters. Perform full database backups regularly, and use differential database backups between full backups to reduce recovery time. Perform frequent transaction log backups to provide redundancy and to truncate the transaction log. Use the Full Recovery model if point-in-time recovery or recovery to a specific mark is needed.