How to increase PROCESSES initialization parameter?

PROCESSES specifies the maximum number of operating system user processes that can simultaneously connect to Oracle. Its value should allow for all background processes such as locks, job queue processes, and parallel execution processes.

Below are the steps to increase the size of  PROCESSES initialization parameter:

• login as sysdba

SQL >  conn sys/  as sysdba

• Check current setting of parameters

SQL>  show parameter sessions;
SQL> show parameter processes
SQL > show parameter transactions

• If you plan to increase the “PROCESSES” parameter you should also plan to increase “SESSIONS”  and ” TRANSACTIONS” parameters

Below is also the basic formula for determining  the parameter values:

                   PROCESSES=X

                   SESSIONS=X*1.1 + 5

                   TRANSACTIONS=SESSIONS*1.1

• These parameters can not be modified in memory and pfile. you have to modify the SPFILE parameter file  and bounce the database

SQL> alter system set processes=500  scope=spfile
SQL> alter system set sessions=555 scope=spfile
SQL> alter system set transactions=610 scope=spfile
SQL> shutdown immediate
SQL> startup