I believe there is the option of using a TNS_ADMIN enivronment variable.
I also seem to remember something about .tnsnames in your personal home
directory. Most of these require some kind of file replication to properly
maintain and a replication server to do the maintenance.
But if I understand your requirements, the best answer would be the
Oracle Name Server.
Although at this time we do no use it (tnsnames.ora in network/admin)
we are planning on evaluating it later this spring (it is going
to be my task). Then the logistical problems with finding and
maintaining tnsnames.ora disappear. With oracle names server you
just have to make sure you have a backup server somewhere in case
your primary does not respond. There is also the idea fo a well
known names server.
> Do anybody know about way to specify to Oracle client where look for
> tnsnames.ora file ?
> I know that by default Oracle client looks tnsnames.ora file in current
> directory and in
> $ORACLE_HOME/net80/admin, but I want to use tnsnames.ora
> from different place. (I have many different Oracle clients versions and
> I don't want to change tnsnames.ora in each installation)
> Thanks, Igor