The relational database management system developed by Codd is a much advanced version when compared to the earlier database management system which were hierarchical and network models. In these earlier models it was not possible for the child to have multiple parents segment. But this drawback was over come in the relational database management system developed by Codd.

______________________________________________________________________________

Some of the notable features of the relational database management systems are that they have atomic values and each of the rows in the relational database management system is unique. The columns have unique name and the values of a particular column are of the same data type. The sequence of the rows and the columns is not important in a relational database management system.

In a relational database management system the data is organized in tables and the relationships are also defined in the tables. A table is a collection of records and each of the records will have the same columns in it. The values may be there are it could be null depending on how the tables are defined in the database. In relational database management systems certain fields are defined as keys. The keys defined help you to join two or more tables on that key so that you can retrieve related data from different tables. Moreover keys also help you to index that particular table on that key so that any search performed on that table key would return the results faster than without the key. Indexing is an important aspect that is done in search intensive databases.

With a step further object orientation is also included in the relational database management systems. This helps the programmer to link the object of the language to that of the objects in the table enabling them to manage the database and also improve the performance of the database. Object storing capabilities is at the core of the object-oriented relational database management systems.