Introduction to X$ Fixed Tables
Norbert Debes · Apress eBooks · 2009
A few X$ tables are mentioned in the documentation, but the vast majority are undocumented. For example X$BH is mentioned in the Oracle9i Performance Tuning Guide as well as the Oracle10g Performance Tuning Guide. The Oracle10g Warehouse Builder Installation and Administration Guide contains a procedure for resolving locking issues pertaining to the library cache by accessing X$KGLLK.1