Oracle ORA-12516 error Solution

A database on the Oracle server encountered an 'ORA-12516: TNS: The Listener could not find the available process' error that meets the protocol stack requirements. To solve this problem, first check the number of existing processes in the database, whether the processes size has been reached.

A. select count (*) from v $ process; obtain the current number of processes in the database.
B. select value from v $ parameter where name = 'processs'; obtain the maximum number of processes.
1. Check the current session count, processes, and sessions values, and find that the number of sessions and the values of the two parameters are very close.
SQL * Plus: Release 11.1.0.6.0-Production on Monday September 21 9:50:21 2009 Copyright (c) 1982,200 7, Oracle. All rights reserved.
SQL> conn/as sysdba
Connected. SQL> select count (*) from v $ session;
COUNT (*)----------
45
SQL> show parameter processes
NAME TYPE VALUE
Db_writer_processes integer 1
Gcs_server_processes integer 0
Job_queue_processes integer 10
Log_archive_max_processes integer 2
Processes integer 50
SQL> show parameter sessions
NAME TYPE VALUE
Java_soft_sessionspace_limit integer 0l
Icense_max_sessions integer 0
License_sessions_warning integer 0
Logmnr_max_persistent_sessions integer 1
Sessions integer 60
Shared_server_sessions integer
 

2. Modify the values of processes and sessions.
SQL> alter system set processes = 300 scope = spfile;
The system has been changed.
SQL> alter system set sessions = 335 scope = spfile;
The system has been changed.
3. Check the processes and sessions parameters, www.bkjia.com, but the change does not take effect.

SQL> show parameter processes
NAME TYPE VALUE
Db_writer_processes integer 1
Gcs_server_processes integer 0
Job_queue_processes integer 10
Log_archive_max_processes integer 2
Processes integer 50
SQL> show parameter sessions
NAME TYPE VALUE
License_max_sessions integer 0
License_sessions_warning integer 0
Logmnr_max_persistent_sessions integer 1
Sessions integer 60
Shared_server_sessions integer
4. Restart the database to make the change take effect.

SQL> shutdown
SQL> startup
SQL> show parameter processes
NAME TYPE VALUE
Db_writer_processes integer 1
Gcs_server_processes integer 0
Job_queue_processes integer 10
Log_archive_max_processes integer 2
Processes integer 300
SQL> show parameter sessions
NAME TYPE VALUE
Java_soft_sessionspace_limit integer 0
License_max_sessions integer 0
License_sessions_warning integer 0
Logmnr_max_persistent_sessions integer 1
Sessions integer 335
Shared_server_sessions integer