1. Self-describing nature of a database system.
2. Insulation between programs and data,and data abstraction.
3. Support of multiple views of the data.
4. sharing of data and multiuser transaction processing.
1. Self-describing nature of a database system:
A fundamental characteristics of the database approach is that the database system contains not only the database itself but aslo a complete definition or description of the database structure and constraints. The definition is stored in the DBMS catalog, which contain information such as the structure of ech file, the type and storage fornmat of each data item, and various constraints on the data. The information stored in the catalog is called mata-data, and it descibes the structure of the primary database.
copy from Fundamentals of Database Systems which is writing by Elmasri & Navathe