Security

V$ views are views that are built on top of X$ views. They do not provide all the information that is in the X$ views. To get the missing information, you have to query the X$ views directly, and this typically requires you to log in as the SYS user. In many sites, the SYS account is off limit to third-party applications for security reasons, but an external program that attaches to the SGA directly can read X$ views without logging in as the SYS user .