What is logical backup in Oracle?
A logical backup copies data, but not physical files, from one location to another. A logical backup is used to move or archive a database, tables, or schemas and to verify database structures.
In summary a logical database backup is a copy of the logical information of a database extracted and stored in a binary format. A physical database backup is a copy of the complete database contents , structure, tables and all relevant transactions you need to restore your database.
In its simplest form, physical backup is the movement of all data from one raw device to another; in the context of file system backup the source devices are disks and the destination devices may include disk, CD-Rom, floppy, Zip drives, and of course, tape.
There are mainly three types of backup are there: Full backup, differential backup, and incremental backup. Let's take a look at each types of backup and its respective pros and cons.
Physical backups are backups of the physical files used in storing and recovering your database, such as datafiles, control files, and archived redo logs. Ultimately, every physical backup is a copy of files storing database information to some other location, whether on disk or some offline storage such as tape.
The RMAN BACKUP command generates a backup set, which is a logical object containing one or more backup pieces. Each backup piece is a physical file in a proprietary, binary format.
RMAN uses a media manager API to work with backup hardware. A user can log in to Oracle RMAN and command it to back up a database. RMAN will then copy the files to the directory specified by the user. By default, RMAN creates backups on disk and generates backup sets rather than image copies.
A logical device is a user-defined name that points to a specific physical backup device (a disk file or tape drive). The initialization of the physical device occurs later, when a backup is written to the backup device.
The RMAN BACKUP command generates a backup set, which is a logical object containing one or more backup pieces. Each backup piece is a physical file in a proprietary, binary format.
A logical device is a user-defined name that points to a specific physical backup device (a disk file or tape drive). The initialization of the physical device occurs later, when a backup is written to the backup device.
Which of the following are logical backup techniques in Oracle?
Logical backups are backups in which the export utility (for example Exp) uses SQL to read database data and then export it into a binary file at the operating system level. You can then import the data back into a database using the import utility (Imp).
The two utilities provided by Oracle for the purpose of logical backup and recovery are called EXPORT, for backup of database objects, and IMPORT, for recovery of database objects in export dump files.
