ORA-04068: existing state of packages has been discarded
It can be avoided by introducing PRAGMA SERIALLY_REUSABLE into package
Reference: http://www.rampant-books.com/t_ora_04068_existing_state_of_packages_string_discarded.htm
Http://www.dba-oracle.com/sf_ora_04068_existing_state_of_packages_string_has_been_discarded.htm