SP2-0618: Cannot find the Session Identifier. Check PLUSTRACE role is enabled

# Problem turning on autotrace with statistics

REDO_TEST@test11>set autotrace on statistics
SP2-0618: Cannot find the Session Identifier. Check PLUSTRACE role is enabled
SP2-0611: Error enabling STATISTICS report

# Fix (courtesy of Tom Kyte)

cd $ORACLE_HOME/rdbms/admin
sqlplus system
@utlxplan
create public synonym plan_table for plan_table;
grant all on plan_table to public;
exit
cd $ORACLE_HOME/sqlplus/admin
sqlplus / as sysdba
@plustrce
grant plustrace to public