2008 TDE and compression

Question

Do these two features work together?

If I want to have an encrypted backup of an encrypted data file can I still do incremental backups? Is TDE capable of decrypting the data file and then re-encrypting only the records I want to backup?

What about encrypting a backup of a non-encrypted data file?

thanks...

Answer 1

Hi,

 

The short answer is TDE will work with data compression but not with backup compression.  Backup compression will functionally work with TDE, but they are not designed to work together so compression will not provide any useful results.  So the best way to have a compressed TDE backup is to first enable data compression.

 

You can perform incremental backup and restores with TDE enabled on the database.

 

SQL Server 2008 is not able to natively handle the encrypted backup of a non-encrypted file.  There should be some third party tools that allow you to do this.

 

Hope this helps,

 

Sung

Answer 2

Is the encryption salted? If it is how do the indexes searches work?