I get error ORA-28113: policy predicate has error when I perform SQL Tuning on my SQL script by going to or using Optimize Current SQL from inside Toad or going directly in SQL Optimizer. I have privileges or grants on the Views only of the tables.
Grant the privileges to access the underlying objects of the View. You will need to be able to access the underlying object in order to optimize. This is because Oracle requires users to have access to the base tables when getting the execution plan of a SQL referenced the view. Note that this is a requirement in Oracle and SQL Optimizer is also constrained by that.