Major Description
Currently function name for the permanent function is getting formed as dbName.WINDOW_FUNC_PREFIX+functionName where as function registry has function name as WINDOW_FUNC_PREFIX+dbName.functionName. This is leading to invalid function error when we use permanent function with window function. Fix has been done such that we form the permanent function name rightly as WINDOW_FUNC_PREFIX+dbName+.+functionName so that it matches with the name in function registry. The functionality for built-in/temporary function would remain the same.