Oracle backup terminology

Term full database backup: includes all data files and at least one control file (remember that all control files in the database are the same) partial database backup: it may include zero or multiple tablespaces, zero or multiple data files, or full backup of control files, that is, each data that contains data and is located in the file to be backed up.

Term full database backup: includes all data files and at least one control file (remember that all control files in the database are the same) partial database backup: it may include zero or multiple tablespaces, zero or multiple data files, or full backup of control files, that is, each data that contains data and is located in the file to be backed up.

Terms
Full database backup: includes all data files and at least one control file (remember that all control files in the database are the same)

Partial database backup: It may include zero or multiple tablespaces, zero or multiple data files, or control files.

Full backup: Creates a copy of each data block in the file that contains the data and is located in the file to be backed up.

Incremental Backup:
Creates copies for all data blocks that have changed since a previous backup. Oracle DB supports two levels of Incremental Backup (0 and 1 ). One-level Incremental Backup can be one of two types: "cumulative" or "differential ". A cumulative backup is used to back up all changes that have occurred since the last backup of level 0. Differential backup is used to back up all changes that have occurred since the last Incremental Backup (which can be level 0 or Level 1 backup ).

Offline backup (also known as "cold" backup or "consistent" backup ):
Indicates the backup performed when the database is not opened. Consistent backup is called because the system change number (SCN) in the data file header matches the SCN in the control file during Backup.

Online backup (also known as "hot" backup or "inconsistent" backup ):
Indicates the backup performed when the database is opened. This is called a non-consistent backup because data files and control files cannot be synchronized when the database is opened. Non-consistent backup must be used after recovery.

Image copy: Refers to a copy of data or archived log files (similar to copying files using only operating system commands ).

Backup set:
A collection of one or more binary files, including one or more data files, control files, server parameter files, or archive log files. When a backup set is used, no empty data blocks are stored, so the backup set occupies less space on disk or tape. By compressing backup sets, You can further reduce the backup space requirements.

The image copy must be backed up to the disk. A backup set can be sent to a disk or directly to a tape.

The advantage of storing backups as image copies is that it can improve the granularity of restoration operations. When using image copies, you only need to retrieve files from the backup location. When using the backup set, you must first retrieve the entire backup set from the backup location before extracting the required files.
The advantage of storing backups as backup sets is that space can be used better. In most databases, 20% or more data blocks are empty. The image copy backs up each data block, even if the data block is empty. Backup sets can significantly reduce the space required for backup. In most systems, the advantage of backup sets is greater than that of image copies.