ORA-12516 Solution

When the client uses pl/SQL dev to connect to the database, a prompt (dedicated server mode) is displayed during login ).
ERROR:
ORA-12516: TNS: listener cocould not find available handler
Matching protocol
Stack
When modifying the parameters, it is found that the first sqlplus instance can be connected to the database through system authentication after being started.
. When the second sqlplus tool is started to connect to the database through system authentication, the connection is found
To an idle routine.
The first sqlplus:
[Oracle @ jason] $ sqlplus/nolog
SQL * Plus: Release 10.2.0.5.0-Production on Wed Aug 17
18:43:11 2011
Copyright (c) 1982,201 0, Oracle. All Rights Reserved.
SQL> conn/as sysdba
Connected.
SQL> show parameter processes;
NAME TYPE VALUE
-----------------------------------------------------------
------------------
Aq_tm_processes integer 0
Db_writer_processes integer 1
Gcs_server_processes integer 0
Job_queue_processes integer 10
Log_archive_max_processes integer 2
Processes integer 22
SQL> show parameter sessions;
NAME TYPE VALUE
-----------------------------------------------------------
------------------
Java_max_sessionspace_size integer 0
Java_soft_sessionspace_limit integer 0
License_max_sessions integer 0
License_sessions_warning integer 0
Logmnr_max_persistent_sessions integer 1
Sessions integer 29
Shared_server_sessions integer
SQL> select count (*) from v $ session;
COUNT (*)
----------
20
SQL> select count (*) from v $ process;
COUNT (*)
----------
21
SQL>
The second sqlplus:
[Oracle @ jason] $ sqlplus/nolog
SQL * Plus: Release 10.2.0.5.0-Production on Wed Aug 17
18:39:55 2011
Copyright (c) 1982,201 0, Oracle. All Rights Reserved.
SQL> conn/as sysdba
Connected to an idle instance.
An error is reported when the test is started to prove that the database is running.
SQL> startup
ORA-01081: cannot start already-running ORACLE-shut it down
First
SQL>
This is a bit hard to understand and I hope to get some advice.
In the first sqlplus connection, modify the processes parameter.
SQL> alter system set processes = 300 scope = spfile;
System altered.
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.
Total System Global Area 1207959552 bytes
Fixed Size 2095864 bytes
Variable Size 369100040 bytes
Database Buffers 822083584 bytes
Redo Buffers 14680064 bytes
Database mounted.
Database opened.
SQL> show parameter sessions;
NAME TYPE VALUE
-----------------------------------------------------------
------------------
Java_max_sessionspace_size integer 0
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
SQL> show parameter processes;
NAME TYPE VALUE
-----------------------------------------------------------
------------------
Aq_tm_processes integer 0
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>
Connect to the database again using pl/SQL on the client and test the connection. The error message "no" is displayed.
Again.
Supplement: sessions = (1.1 * PROCESSES) + 5
Note: This environment is a test environment.

 
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