Using a database, either via a SQL injection or via direct connection, as a stepping stone to control the underlying operating system can be achieved. There is much to say on operating system control by owning a database server: Windows registry access, anti-forensics technique to establish an out-of-band stealth connection, buffer overflow exploitation with memory protections bypass and custom user-defined function injection. These slides have been presented at SOURCE Conference in Barcelona on September 21, 2009.