ORA-00020 maximum number of processes exceeded
Cause: All process state objects are in use.
Action: Increase the value of the PROCESSES initialization parameter.
ORA-00020 comes under "Oracle Database Server Messages". These messages are generated by the Oracle database server when running any Oracle program.
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;
sql> shutdown abort
sql> startup
#source : https://www.linkedin.com/pulse/how-increase-processes-initialization-parameter-ora-00020-jain
