TravisDBA (7/6/2010)
I am talking about compressing the backup, not compressing the database then encrypting it,, But anyway, I don't remember seeing that anywhere in SQL 2008 BOL? That would be nice if that little important detail was in there, but what else is new. 🙂
SQL Server 2008 Books Online does specifically mention that, but don't let that get in the way of a good gripe.
"SQL Server 2008 Books Online (August 2008)
Understanding Transparent Data Encryption (TDE)
...
Encrypted data compresses significantly less than equivalent unencrypted data. If TDE is used to encrypt a database, backup compression will not be able to significantly compress the backup storage. Therefore, using TDE and backup compression together is not recommended.
..."