The Oracle Database 11.2 Express Edition beta has now been released and can be downloaded. Oracle Database XE, as it’s called, is a stripped-down, free version of Oracle Database. Oracle released the paid version of 11g in 2007.
Oracle Database XE allows companies to try out Oracle Database before trying it, or to do development on the platform without paying for it. As such, it has significant limitations, as stated in its documentation. No more than 11GB of data can be placed in it, and it can use no more than 1GB of RAM. It is also short of several high-availability, scalability and security features.