RMAN Backup Compressions tested in our Test ENV
Posted by Mir Sayeed Hassan on October 2nd, 2017
RMAN Backup Compressions tested in our Test ENV
RMAN Backup Compressions
The compression levels are BASIC, HIGH, MEDIUM and LOW
To use this option, we can run the following RMAN commands
RMAN> CONFIGURE DEVICE TYPE DISK BACKUP TYPE TO COMPRESSED BACKUPSET; followed by ..
RMAN> CONFIGURE COMPRESSION ALGORITHM ‘BASIC’; -Default by Oracle or
RMAN> CONFIGURE COMPRESSION ALGORITHM ‘HIGH’; or
RMAN> CONFIGURE COMPRESSION ALGORITHM ‘MEDIUM’; or
RMAN> CONFIGURE COMPRESSION ALGORITHM ‘LOW’;
Tests carried out our Etick – Test Database & Verified. However, it should be noted that use of
LOW, MEDIUM and HIGH, The backup set size and backup duration are shown below.
Compression Level ‘Basic’
backupset size: 327 M
time: 56 sec
Compression Level ‘HIGH’
backupset size: 266 M
time: 3 mins
Compression Level ‘Medium’
backupset size: 346 M
time: 35 sec
Compression Level ‘Low’
backupset size: 418 M
time: 15 sec
To summaries’ we can conclude:
LOW – corresponds to LZO (11gR2) – smallest compression ratio, fastest
MEDIUM – corresponds to ZLIB (11gR1) – good compression ratio, slower than LOW
HIGH – corresponds to unmodified BZIP2 (11gR2) – highest compression ratio, slowest
BASIC (which is free) – corresponds to BZIP2 (10g style compression) – compression ratio in the range of MEDIUM, but slower
To verify the time taken by backup & size etc
sqlplus> desc v$backup_files
===============Hence Refer my test example in future =================