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?
The easiest way is probably to check the PATH environment variable of the process that is connecting to the database. Most likely the tnsnames.ora file is in first Oracle bin directory in path..\network\admin. TNS_ADMIN environment variable or value in registry (for the current Oracle home) may override this.
Using filemon like suggested by others will also do the trick.