sqlnet.ora or tnsnames.ora changes require reboot?

Anytime you change Oracle’s sqlnet.ora or tnsnames.ora files, does the system require a reboot? In my instance, I only have the Oracle client installed on the machine I’m referring to, but out of curiosity what would it mean for an Oracle server installation?

In general, no. A tnsnames.ora change shouldn’t require a reboot but some applications will read and parse the tnsnames.ora at startup to be able to present a drop-down list of servers to the user, for example, and will cache whatever was read when the application started up rather than re-reading the file. Depending on the situation, it might be easiest to reboot a Windows client rather than figuring out how to kill and restart any applications that might have the data cached.

A sqlnet.ora change might benefit from a reboot for the sake of consistency though it is not required. If you are doing something like enabling dead connection detection on a server by setting sqlnet.expire_time, for example, it probably makes sense to reboot the server to make sure that the setting applies to all connections rather than just new connections– if you’re trying to debug why a particular dead connection is still hanging around, knowing that the server was restarted and that you’re not looking at some artifact of a connection that was opened prior to the setting being made would generally be helpful.

from my expierience wih sqlplus and some other tools:

• tnsnames.ora is read whenever a clients wants to open a connection
• sqlnet.ora is read whenever a client process starts up

at least for sqlplus you can verify this easily:

• start sqlplus and then add a new entry in tnsnames.ora. you can use it.
• start sqlplus and then configure tracing in sqlnet.ora, this should not work:

 
trace_directory_clint = c:trace
trace_timestamp_client = on
trace_level_client = 16
trace_unique_client = on

But of course other application could behave in another way

Of course the trace will not work if the trace directory if the trace_directory does not exist or is not writable. so you yshould also check that your tracing works if you coigure it before you start sqlplus