8.175 V$RMAN_COMPRESSION_ALGORITHM

V$RMAN_COMPRESSION_ALGORITHM provides descriptions of supported compression algorithms. It is used by the RMAN client.

Column Datatype Description

ALGORITHM_ID

NUMBER

Algorithm ID

ALGORITHM_NAME

VARCHAR2(64)

Name of the algorithm (for example, LOW, MEDIUM, DEFAULT, or HIGH)

INITIAL_RELEASE

VARCHAR2(18)

First Oracle Database release when this compression algorithm was available

TERMINAL_RELEASE

VARCHAR2(18)

Last Oracle Database release that supported using this compression algorithm to create new backups. Existing backups can always be restored, even if they use a deprecated compression algorithm.

ALGORITHM_DESCRIPTION

VARCHAR2(64)

Description of the algorithm

ALGORITHM_COMPATIBILITY

VARCHAR2(18)

Required database compatibility level for the algorithm (for example, 11.2.0 for DEFAULT)

IS_VALID

VARCHAR2(3)

Indicates whether the algorithm is valid with regard to the compatibility setting (YES) or not (NO). The value is YES if ALGORITHM_COMPATIBILITY <= DATABASE_COMPATIBILITY.

REQUIRES_ACO

VARCHAR2(3)

Indicates whether the algorithm requires the Advanced Compression Option (YES) or not (NO)

IS_DEFAULT

VARCHAR2(3)

Indicates whether the algorithm is the default compression algorithm that RMAN uses to create compressed backup sets (YES) or not (NO)

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

  • 0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.

  • 1: This value is used for rows containing data that pertain to only the root

  • n: Where n is the applicable container ID for the rows containing data