In this chapter, we've covered the fundamental concepts of Oracle database security. We've examined the responsibility for security that comes with being a DBA. We've explored ways to create database users and assign them privileges at both the system and object level. We've learned to use roles to encapsulate various system and object privileges. We've looked at profiles and the ways with which we can set limits on both password and resource usage characteristics. Finally, we've explored the subject of database auditing and how it can be used to monitor database activity. In our next chapter, we'll look at another important concept of the relational database, the subject of concurrency and undo management.