We are using TDE ( Transparent Data Encryption ) on Oracle RMAN and MSSQL databases and have noticed that with the Oracle RMAN databases we are getting very low deduplication rates but in MSSQL the dedupe rates are similar to MSSQL databases that don't use TDE.
Does Netabackup handle TDE backups differently for Oracle RMAN and MSSQL, is there a way to get better dedupe rates for Oracle RMAN TDE databases ?
Encryption does not work well with dedupe. Encryption is "random" (high entropy) , whereas dedupe looks for patterns in data that are similar.
So if encryption is needed, you dedupe first and then encrypt.
If you encrypt first and the dedupe, dedupe rate must my nature always be near 0 because of random encrypted data.