What is RDBMS?

A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd, of IBM's San Jose Research Laboratory. Many popular databases currently in use are based on the relational database model. RDBMS are database management systems that maintain data records and indices in tables. Relationships may be created and maintained across and among the data and tables. In a relational database, relationships between data items are expressed by means of tables. Interdependencies among these tables are expressed by data values rather than by pointers. This allows a high degree of  data independence. An RDBMS has the capability to recombine the data items from different files, providing powerful tools for data usage.

What is the difference between DBMS and RDBMS?

• DBMS – Data Base Management System


• RDBMS – Relational Data Base Management System or Relational DBMS

A DBMS has to be persistent, that is it should be accessible when the program created the data ceases to exist or even the application that created the data restarted. A DBMS also has to provide some uniform methods independent of a specific application for accessing the information that is stored.

RDBMS adds the additional condition that the system supports a tabular structure of the data, with enforced relationships between the tables. This excludes the databases that don’t support a tabular structure or don’t enforce relationships between tables.

DBMS does not impose any constraints or security with regard to data manipulation it is used or the programmer responsibility to ensure the ACID PROPERTY of the database whereas the RDBMS is more with this regards because RDBMS defines the integrity constraint for the purpose of holding ACID PROPERTY. RDBMS may be or may not be Client Server Database System.

Examples :

• DBMS – File System, XML


• RDBMS – SQL Server, Oracle

More references:

1. "Oracle the clear leader in $24 billion RDBMS market".


2. "Market Share".


3. "DB-Engines Ranking of Relational DBMS".


4. "Oracle Timeline" (PDF). Profit Magazine (Oracle) 12 (2): 26. May 2007.


5. "A Relational Model of Data for Large Shared Data Banks"