New DB instance and configuration after Oracle installation

ORA-12514 The TNS listener is currently unable to identify the resolution of the request service in the connection descriptor (2011-01-20 13:50:37) reprint http://blog.sina.com.cn/s/blog_5007d1b10100oqo8.html

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Morning colleague with PL/SQL connection to the Oracle database in the virtual machine, found that the "ORA-12514 TNS Listener currently does not recognize the connection Descriptor request Service " error, to help it solve, found that many people have encountered such problems, so write here.

Maybe you haven't met for a reason like this:

After your Oracle installation succeeds, the database has not been stopped (that is, the database is started), and after the client configuration succeeds, there should be no problem.

And once you're like my colleague, sometimes the Oracle is installed in a virtual machine, and after Oracle is installed, no listening configuration is being performed, then the virtual machine restarts, and then there is a ORA-12514 problem. Such as

Here's how to solve the idea:

The client does not hear the instance service name according to the error message

1. Start the database by restarting the service, and again the connection is still unable to connect to the server.

2, since the first method does not solve the problem, then the second method. Consider listening Listener.ora

You may not have to specify the service name for the listener in the Listener profile Listener.ora (which is not specified after installing oracle10g). Normally, as long as the database starts, the client connects to the database with no problems, but sometimes a ORA-12514 error occurs when a recurring startup is turned off.

Since no listener is specified in the Listener.ora, we can specify the listener instance name in the Listener.ora file so that the problem should be connected.

The steps are as follows:

• In Oracle Server Oracle installation directory (my under E:\Oracle10g, everyone is not the same, according to their own situation to find) Network/admin directory found Listener.ora me as shown

# Listener.ora Network Configuration File:e:\oracle10g\network\admin\listener.ora
# Generated by Oracle configuration tools.

Sid_list_listener =
(Sid_list =
(Sid_desc =
(Sid_name = Plsextproc)
(Oracle_home = E:\Oracle10g)
(program = Extproc)
)
(Sid_desc =
(Global_dbname = ORCL)
(Oracle_home = E:\Oracle10g)
(Sid_name = ORCL)
)
)

LISTENER =
(Description_list =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = IPC) (KEY = EXTPROC1))
(ADDRESS = (PROTOCOL = TCP) (HOST = onest) (PORT = 1521))
)
)

Marked red for the part that I added, ORCL is the instance name of the listener.

• The monitoring service is then restarted in the Oracle server's service, and then the Oracle client is configured to listen again on the ORCL instance, as shown in
• The result appears as a hint.
  
• At this time we do not worry, only need to restart the Oracle server, the connection is successful again. This is also our configuration after Listener.ora monitoring, often forget. Try again, you can see that the client can connect to the Oracle server, and PL/SQL is connected again and there is no problem.

Some friends, while configuring the client, connect to the database successfully, and when using PL/SQL, the problem appears as shown. And how does this work? Why is the Oracle client connected successfully and PL/SQL not?

The reason for this is that it may be that when you configure the Oracle client again, there may be some errors in the steps, although the link succeeds. When you use the Net Cofiguration Assistant client to reconfigure the ORCL, instead of adding, we should process the following steps, there will be no problem.

1, if the net Cofiguration assistant already has the ORCL. We can reconfigure

2, if the net Cofiguration Assistant does not have ORCL, we should add the concrete interface as shown.

If you have no problem with this step, Listener.ora has successfully modified and restarted the Oracle server, both Oracle client and PL/SQL can successfully connect to the database.

Sum up. When you encounter the "ORA-12514 TNS Listener does not currently recognize the request service in connection descriptor " error, the resolution step:

1. Start the database by restarting the service and try again.

2, if the first method is not feasible, we use the second method

• Add Listener.ora correctly;
• Restart the Oracle server and check that all Oracle services are started;
• Oracle Client Net Cofiguration assistant correctly add or reconfigure instance names

Hope this blog post, can solve everyone's problem.