Oracle Backup: Logical vs Physical

Logical backup and physical backup are two commonly used backup methods in Oracle databases, and they have the following distinctions:

1. Logical backup involves exporting data and object structures from a database into a backup file using SQL commands or tools, capturing logical information such as table structures, data, and stored procedures. On the other hand, physical backup entails directly copying database files or using tools provided by Oracle, like RMAN, to back up the physical storage structures of the database.
2. Logical backup is a backup at the logical level, which backs up logical data and object information in the database, not directly backing up the database files themselves. Physical backup directly backs up database files, backing up the physical storage structure of the database.
3. The recovery speed of logical backups is slow because it requires re-importing the logical information from the backup files into the database. In contrast, the recovery speed of physical backups is faster because it can directly copy the database files or restore the database using tools like RMAN.
4. Logical backups are typically used for exporting data, migrating databases, backing up database structures, etc., and are suitable for small databases or databases that require regular backups. Physical backups, on the other hand, are usually used for backing up and restoring entire databases, and are suitable for large databases or emergency recovery situations.

In general, logical backups are used to backup the logical information and operations of a database, while physical backups are used to backup the physical storage structure and the entire database. In practical applications, it is common to combine logical and physical backups to ensure the integrity and security of the database.