I'm trying to backup my organization's production databases on SQL Server 2008 R2 Standard. I'm using a T-SQL script to backup with DIFFERENTIAL and COMPRESSION selected.
I'm astounded at the size of the backups relative to the mdf file sizes. For example, we have one sharepoint database that is 307 mbs in mdf. It's backup--with differential and compression selected--is 280 mbs. How is this compressed or differential?
I've tried backing up using .7z and zip and it doesn't really achieve any more compression.
Am I missing something? Why would a differential backup compressed be almost the size of the mdf?