ORA-00020: maximum number of processes

How to check and resolve : ORA-00020: maximum number of processes

1. Login into the Oracle Database and if you cannot sqlplus into it. Try killing a few oracle server processes.

ps -ef|grep oracle
kill -9

2. Try to sqlpus now, check existing sessions:

select inst_id, username, machine, program, status, count(*) "Connections"
from gv$session
where username is not null
group by inst_id, username, machine, program, status
order by 1, 6 desc;

3. Increase the number of processes and sessions

SQL> alter system set processes=700 scope=spfile sid='*';

System altered.


SQL> alter system set sessions=1072 scope=spfile sid='*';

System altered.

4. Bounce the db

if Oracle RAC

[oracle@ test-db2 ~]$ srvctl stop database -d DB_NAME

[oracle@ test-db2 ~]$ srvctl start database -d DB_NAME

[oracle@ test-db2 ~]$ srvctl status database -d DB_NAME
Instance TEST1 is running on node test-db1
Instance TEST2 is running on node test-db2

5. Verify if the parameters are increased using the below query

select * from gv$resource_limit

where resource_name in ('processes', 'sessions')

order by 2, 1;

For example: