SQL> show parameter session

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
java_max_sessionspace_size integer 0
java_soft_sessionspace_limit integer 0
license_max_sessions integer 0
license_sessions_warning integer 0
logmnr_max_persistent_sessions integer 1
session_cached_cursors integer 20
session_max_open_files integer 10
sessions integer 170
shared_server_sessions integer

SQL> alter system set processes=300 scope=spfile;

System altered

SQL> alter system set sessions=335 scope=spfile;