How to log attempts to connect as a locked user account

I want to design poor man's auditing for one single case: My user accounts are locked, and I want to log the connection attempts. But since there is no BEFORE LOGON ON DATABASE trigger (for rather obvious reasons).

(Background info: Decommissioning of a test database: I want to find ancient jobs or autistic developers that don't complain, before dropping the storage there.)

Is there any best practice for this? I'm using 9i, 10g and 11g.

Thanks for any response
Martin Klier

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