ORA-00018: maximum number of sessions exceeded

ORA-00018: maximum number of sessions exceeded

Cause: All session state objects are in use.

Action: Increase the value of the SESSIONS initialization parameter.

Explanation1 :

1. You can wait a few minutes and try to re-execute the statement(s).
2. You can shut down Oracle, increase the SESSIONS parameter in the initialization parameter file, and restart Oracle.

Explanation2 :

ORA-00018 comes under "Oracle Database Server Messages". These messages are generated
by the Oracle database server when running any Oracle program.

How to increase SESSION 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 "sessions" parameter you should also plan to increase
"processes 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

Be Happy.....