During a recent troubleshooting, we came across a requirement where we wanted to know what all locations does Oracle searches tnsnames.ora ? So writing this quick post for the analysis that we did and the results we reached during this exercise. You might already aware of tnsnames.ora in path defined by TNS_ADMIN variable and default…
This error is received when the listener received a request to establish a connection to a database or other service but the connect descriptor received by the listener specified a SID for an instance (usually a database instance) that either has not yet dynamically registered with the listener or has not been statically configured for…
This error appears when the process of starting up a dedicated server process failed and it could be either because the executable could not be found or the environment isn’t set up correctly. Turn on tracing at the ADMIN level and re-execute the operation. Tracing can be set by adding following clause in listener.ora file…
This error occurs when there was no default service configured for the listener and SERVICE_NAME was missing from the request received by the listener. When a user tries to connect to the listener, it may be servicing several different databases. If user specifies a service name in the connect request then the listener will connect…
TNS:listener received no CONNECT_DATA from clientCause: No CONNECT_DATA was passed to the listener.Action: Check that the service name resolved from TNSNAMES.ORA has the CONNECT_DATA component of the connect descriptor. Below is the sample entry of tnsnames.ora:- #When using SERVICE_NAME in CONNECT_DATA componentorcl.example.com = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = myserver.example.com)(PORT =…
This is a quick note to cover ORA-12547: TNS:lost contact error, I would try to include all possible causes of ORA-12547: TNS:lost contact error so that this post itself could assist you in sorting the issue. ORA-12547: TNS:lost contact error could be due to any of the following reasons:- Incorrect permissions on the ORACLE executable.…
This post details how to resolve listener connection issues when DB & listener are started but still connect fails with following errors:- ORA-12505 TNS:listener could not resolve SID given in connect descriptor TNS-12505 TNS:listener could not resolve SID given in connect descriptor ORA-12514 TNS:listener could not resolve SERVICE_NAME given in connect descriptor TNS-12514 TNS:listener could…
Oracle Database Internal Mechanism 