Contents Index Backup and Data Recovery Protecting your data against failure

ASA Database Administration Guide
  Backup and Data Recovery

Introduction to backup and recovery


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.

Restoring databases from a backup is one aspect of database recovery. The other aspect is recovery from operating system or database server crashes, and improper shutdowns. 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.

Chapter contents 

This chapter contains the following material:

Questions and answers 
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 carry out 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? Designing 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? Ensuring your database is valid Validating a database
How can I be sure that my transaction log is not corrupt? Validating the transaction log on database startup Validating a transaction log
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? Protecting against total machine failure Making a live backup
How do I carry out 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 Recovering from media failure on a mirrored transaction log

Protecting your data against failure
Ways of making backups

Contents Index Backup and Data Recovery Protecting your data against failure