I don't know why "Performance" Tab of DBConsole is disabled (no hyperlink). I have checked it on different browsers and its same on all browsers. The environment I am using is Windows 2008 Server R2, Oracle 11g - 184.108.40.206 and Oracle Fail Safe environment is also configured. All other tabs are working fine, other environments (DEV, TEST) are also working fine showing the Performance matriexes, its only the PROD environment in which "Performance" tab is not clickable. Database parameters are also set appropriately.