Using Easy Connect (EZCONNECT) Naming Method to Connect to Oracle Databases

by Eric Jenkinson on August 23, 2010 Tagged: , ,

Easy Connection (EZCONNECT) is a method of connecting to an Oracle database that eliminates the need for service name look up. All of the information needed to resolve the connection is included in the connection string. With 10g and higher installations of the Oracle Client and Database Easy Connect naming is automatically configured at installation time.
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Creating an Oracle Listener with Oracle Network Configuration Assistant

by Eric Jenkinson on August 22, 2010 Tagged: ,

In order to allow remote connections to an Oracle database the database must be registered with an Oracle Listener. An Oracle Listener is created during the Oracle Database software installation process if a database was created during the installation if not you will need to create a Listener manually.
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ORA-12545: Connect failed because target host or object does not exist

by Eric Jenkinson on July 14, 2010 Tagged: , ,

Connectivity errors are common questions on Oracle related forums and in many cases they are highly misunderstood by the poster of the questions and some responders.

This aim of this document is to show a method for diagnosis and resolution to a scenario in which an ORA-12545 is raised during the connection to a database.
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Message #### not found when attempting to start the listener, tnsping, or SQL*Plus

by Eric Jenkinson on July 12, 2010 Tagged: , , ,

Problem

When attempting to start the listener you receive the following error.

[oracle@ora2 ~]$ lsnrctl start

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 06-JUL-2010 10:38:43

Copyright (c) 1991, 2009, Oracle.  All rights reserved.

Message 1070 not found; No message file for product=network, facility=TNSTNS-12545: Message 12545 not found; No message file for product=network, facility=TNS
 TNS-12560: Message 12560 not found; No message file for product=network, facility=TNS
  TNS-00515: Message 515 not found; No message file for product=network, facility=TNS
   Linux Error: 2: No such file or directory
[oracle@ora2 ~]$

Or you may receive the following when attempting to use tnsping.

[oracle@ora2 ~]$ tnsping proddb

TNS Ping Utility for Linux: Version 11.2.0.1.0 - Production on 06-JUL-2010 10:38:30

Copyright (c) 1997, 2009, Oracle.  All rights reserved.

Message 3511 not found; No message file for product=network, facility=TNSTNS-03505: Message 3505 not found; No message file for product=network, facility=TNS
[oracle@ora2 ~]$

Or you might have attempted a connection using SQL*Plus and received the following error.

[oracle@ora2 ~]$ sqlplus /nolog
Error 6 initializing SQL*Plus
SP2-0667: Message file sp1<lang>.msb not found
SP2-0750: You may need to set ORACLE_HOME to your Oracle software directory
[oracle@ora2 ~]$

Of the three errors messages, the message returned using SQL*Plus is the most descriptive and actually points to the problem causing all three.

The above mentioned utilities along with others included with the Oracle software need to have the ORACLE_HOME environment variable pointing to the proper location. In the above mentioned cases the utilities were unable access messages files. In particular the both the lsnrctl and tsnping were unable to access message files ORACLE_HOME/network/mesg and SQL*Plus as unable to access message files in ORACLE_HOME/sqlplus/mesg.

The message files contain status and error message used by the various utilities provided by Oracle.

Solution

Set the ORACLE_HOME environment variable to the proper location and retry the utility.

Setting up Oracle Net Services Tracing on the Client and Server

by Eric Jenkinson on July 6, 2010 Tagged: , , ,

Tracing the Oracle Net Services provides detailed information to aid in diagnosing connectivity issues. This document will detail the parameters used in tracing Oracle Net Services along with providing an example of tracing a connection to a database.
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Configure Static Service Information for a Database

by Eric Jenkinson on April 6, 2010 Tagged: ,

The PMON process registers service information with the local listener by default. For most uses this is all that is needed to successfully connect to the database for use. If you are using a database release earlier than 8i or you need to remotely start the database from a tool other than Enterprise Manager, you will need to configure static service registration.
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