Query hints are additional, implementation-specific configuration settings. You can use hints in your queries in the following format:
setHint("hint-name", hint-value)
For example:
Customer customer = (Customer)entityMgr.
createNamedQuery("findCustomerBySSN").
setParameter("SSN", "123-12-1234").
setHint("toplink.refresh", true).
getSingleResult();
For more information about the query hints available with the default provider, see Query Hints in TopLink JPA Extensions Reference.