See who is logging in with a userid

Hi all.

Quick question.

How can I tell if someone is logging in to our unix servers with an application id and not their personal id?

Thanks

What is your OS/Platform?

You might be able to leverage the last command or some other system log to identify the machine that a User is logging in from.

Sorry.

SunOS 5.9 Generic_112233-07 sun4u sparc SUNW,Sun-Fire-480R

What I am trying to accomplish is:

We recently implemented personal user id's for two of our staff and they are supposed to use these id's to login and su to the oracle user instead of logging in directly to the oracle user.

I want to verify that they are using their id's and su'ing...
Keep in mind that they may not log in to the server for weeks at a time so I could be searching my su log for months and either assume they are not using it or are not logging in to the server. either way I need to know.

Thanks for your assistance.