ORA-00020: maximum number of processes

To fix the above we need to increase processes initialization value or to find what is using the processes.

How to increase PROCESSES initialization parameter:

1.  Login as sysdba
    sqlplus / as sysdba
   
2.  Check Current Setting of Parameters
    sql> show parameter sessions
    sql> show parameter processes
    sql> show parameter transactions

3.  If you are planning to increase "PROCESSES" parameter you should also plan to increase "sessions and "transactions" parameters
    A basic formula for determining  these parameter values is as follows:
   
    processes=x
    sessions=x*1.1+5
    transactions=sessions*1.1
 
4.  These paramters can't be modified in memory. You have to modify the spfile only (scope=spfile) and bounce the instance.
    sql> alter system set processes=500 scope=spfile;
    sql> alter system set sessions=555 scope=spfile;
    sql> alter system set transactions=610 scope=spfile;