Common Oracle TNS Errors

In this post , I am trying to cover common TNS errors and possible corrective measures. ORA-12154: TNS:could not resolve service name SQL> connect SYSTEM/manager@DEV ERROR: ORA-12154: TNS:could not resolve service name The most common TNS error mostly due to multiple ORACLE HOME, tnsnames.ora and sqlnet.ora conflicts. Check that the instance or database name is [...]

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Connections and Sessions

Establishing a Connection Before users can submit SQL statements to an Oracle database, they must connect to an instance. The user starts a tool such as SQL*Plus or runs an application developed using a tool such as Oracle Forms. This application or tool is executed as a user process. In the most basic configuration, when [...]

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Oracle Listener and Service Name

Oracle Net Listener The one operation unique to the Oracle database server side is the act of receiving the initial connection through an Oracle Net listener. The Oracle Net listener, commonly known as the listener, brokers a client request, handing off the request to the server. The listener is configured with a protocol address. Clients [...]

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Oracle Network Issues Link

Network DBA This link contains common network issues for Oracle Connectivity along with brief description of network files. NETWORK DBA  1. LISTENER.ORA file It is a server side file and contains information regarding network configuration parameters. It can be found in the ORACLE_HOME/network/admin directory on the server. Sample File SID_LIST_LISTENER =   (SID_LIST =     [...]

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