С помощью аудита

System Administration Guide
Chapter 11
Auditing

As a System Security Officer, you can establish auditing for events such as:

* Server-wide, security-relevant events
* Creating, deleting, and modifying database objects
* All actions by a particular user or all actions by users with a particular role active
* Granting or revoking database access
* Importing or exporting data
* Logins and logouts