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`^Foot 1	`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`^Footref 1	`VARCHAR2(3)`	Indicates whether the algorithm is the default compression algorithm that RMAN uses to create compressed backup sets (`YES`) or not (`NO`)

^Footnote 1This column is available starting with Oracle Database 11g Release 2 (11.2.0.2).