Oracle - What TNS Names file am I using?

Question

Sometimes I get Oracle connection problems because I can\'t figure out which tnsnames.ora file my database client is using.

What\'s the best way to figure this out?

Answer 1

There is another place where the TNS location is stored: If you're using Windows, open regedit and navigate to My HKEY Local Machine/Software/ORACLE/KEY_OraClient10_home1 where KEY_OraClient10_home1 is your Oracle home. If there is a string entry called TNS_ADMIN, then the value of that entry will point to the TNS file that Oracle is using on your computer.

Answer 2

Codeslave asks "Shouldn't it always be "$ORACLE_ HOME/network/admin/tnsnames.ora"? The answer is no, it isn't. Consider these two invocations of tnsping on the same machine:

C:\Documents and Settings\me>D:\Oracle\10.2.0_DB\BIN\tnsping orcl

TNS Ping Utility for 32-bit Windows: Version 10.2.0.4.0 - Production on 09-OCT-2
008 14:30:12

Copyright (c) 1997,  2007, Oracle.  All rights reserved.

Used parameter files:
D:\Oracle\10.2.0_DB\network\admin\sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = xxxx
)(PORT = 1521)) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = ORCL)))

OK (40 msec)

C:\Documents and Settings\me>tnsping orcl

TNS Ping Utility for 32-bit Windows: Version 10.2.0.1.0 - Production on 09-OCT-2
008 14:30:21

Copyright (c) 1997, 2005, Oracle.  All rights reserved.

Used parameter files:
D:\oracle\10.2.0_Client\network\admin\sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)
(HOST = XXXX)(PORT = 1521))) (CONNECT_DATA = (SERVICE_NAME = ORCL)))
OK (20 msec)

C:\Documents and Settings\me>

Note the two different parameter file locations, that are dependent on which tnsping executable you're running (and perhaps where it's being run from). For tnsnames-based oracle networking, using the TNS_ADMIN variable is the only way to ensure you're getting a consistent tnsnames.ora file. (NOTE: Windows-centric answer)

Answer 3

Not direct answer to your question, but I've been quite frustrated myself trying find and update all of the tnsnames files, as I had several oracle installs: Client, BI tools, OWB, etc, each of which had its own oracle home. I ended up creating a utility called TNSNamesSync that will update all of the tnsnames in all of the oracle homes. It's under the MIT license, free to use here https://github.com/artybug/TNSNamesSync/releases

The docs are here: https://github.com/artchik/TNSNamesSync/blob/master/README.md

This is for Windows only, though.

Answer 4

For Windows: Filemon from SysInternals will show you what files are being accessed.

Remember to set your filters so you are not overwhelmed by the chatty file system traffic.

Added: Filemon does not work with newer Windows versions, so you might have to use Process Monitor.

Answer 5

Shouldn't it always be "$ORACLE_ HOME/network/admin/tnsnames.ora"? Then you can just do "echo $oracle_ home" or the *nix equivalent.

@Pete Holberton You are entirely correct. Which reminds me, there's another monkey wrench in the works called TWO_ TASK

According http://www.orafaq.com/wiki/TNS_ADMIN
TNS_ADMIN is an environment variable that points to the directory where the SQL*Net configuration files (like sqlnet.ora and tnsnames.ora) are located.