A backup is a copy of the information in a database, held in some physically separate location from your database. If the database becomes unavailable, perhaps because of damage to a disk drive, you can restore it from the backup. Depending on the nature of the damage, it is often possible to restore from backups all committed changes to the database up to the time it became unavailable.
Recovery happens when the operating system or database server crashes, or the database server does not shut down properly. The database server checks on database startup whether the database was shut down cleanly at the end of the previous session. If it was not, the server executes an automatic recovery process to restore information. This mechanism recovers all changes up to the most recently committed transaction.
| To answer the question ... | Consider reading ... |
|---|---|
| What is a backup? | Introduction to backup and recovery |
| What is recovery? | Introduction to backup and recovery |
| What is a transaction log? | The transaction log |
| What are media and system failure? | Protecting your data against failure |
| From what kinds of failure do backups protect my data? | Protecting your data against failure |
| What tools are available for backups? | Ways of making backups |
| What types of backup are available? | Types of backup |
| What type of backup should I use? | Designing backup procedures |
| If my database file or transaction log becomes corrupt, what data may be lost? | Protecting your data against media failure |
| How are backups executed? | Understanding backups |
| How often do I perform backups? | Scheduling backups |
| Can I schedule automatic backups? | Scheduling backups |
| My database is involved in replication. How does this affect my backup strategy? |
A backup scheme for databases involved in replication Backup methods for remote databases in replication installations |
| How can I backup to tape? | Backing up a database directly to tape |
| How do I plan a backup schedule? | Automating tasks using schedules and eventsDesigning a backup and recovery plan |
| Can I automate backups? | Automating tasks using schedules and events |
| How can I be sure that my database file is not corrupt? | |
| How can I be sure that my transaction log is not corrupt? | |
| How can I run my database for maximum protection against failures? | Configuring your database for data protection |
| How can I ensure high availability and machine redundancy? | |
| How do I perform a backup? | Making a full backup |
| How do I restore data from backups when a failure occurs? |
Recovering from media failure on the database file Recovering from media failure on an unmirrored transaction log |
| How do I create a maintenance plan for a database? | Creating a maintenance plan |
Protecting your data against failure
Ways of making backups
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