Which of the following is true concerning open-source DBMS?

A. A single definition of the same data entity B. Familiarity with existing data C. Missing data elements D. All of the above

A. Tune database performance B. Establish backup and recovery procedures C. Resolve data ownership issues D. Protect the security of the database

A. Data modeling B. Database design C. Metadata D. All of the above

A. Authentication policies B. Limiting particular areas within a building to only authorized people C. Ensure appropriate responses rates are in external maintenance agreements D. All of the above