Lay The Tables ... For the Datum is Ready

     The story of how relational database came to be accepted is one of “everything has its place” and “all in good time”.  The idea was first put forth in 1970 by Dr. E.F. Codd, a computer scientist, in a paper titled, “A Relational Model of Data for Large Shared Banks”, which was published in the Communications of the A C M Magazine.

(Codd)

      The idea was brilliant but remained dormant as the information systems community assessed its performance in the real world and cast doubts on it. Moreover network and hierarchical database management systems (DBMS) were at their peak levels and companies became reluctant to abandon them and continued to ride upon their successes.

     But relational database was simply a piece in the jigsaw puzzle. A decade later personal computer’s (PC) came to be popularized, and the normalization technique, which like the PC deemed out to be more compatible with relational tables than hierarchical and network models. 

     By this time, developers were looking for a DBMS that was less cumbersome and easy to handle. The table structure based upon relationships, a.k.a 'relational database' become popular and finally came to be accepted.

     In the relational model every entity interacts with another entity in one to many ways, that is, one -to-one, one-to-many and many-to-many. It is an inhibition-less sort of modeling structure as opposed to the regimen data structure of network and hierarchical.

     The following table substantiates the advantages and disadvantages of hierarchal, network and the multimedia capable object oriented based database management system.

Type of DBMS	Advantages	Disadvantages
Hierarchical	Data can be accessed rapidly as relationships between records are defined in advance.	Relationships between “children” entities are not permitted.
Network	More flexible as connections between different types of data are allowed.	Limit on the number of connections.
Relational	User need not traverse down a hierarchy or network to access data. The data files are relational to each other. The structure is easy to use and data entries can be modified without structure redefinition.	Data search sessions maybe slower.
Object-oriented	Handles new data types such as videos and graphics.	High cost

     However, all four have found acceptance in current day database programming world; the network and hierarchical made a comeback when XML became popular in the 1990’s.  Although the relational model can easily model network or hierarchical data, depending on the requirements of a project, IT professionals choose between different DBMS’s. 

References

Codd, Frank. "A Relational Model of Data for Large Shared Banks." . Communications of the  
    ACM, Feb 1970. Web. 18 Jul 2012. <http://www.seas.upenn.edu/~zives/03f/cis550/codd.pdf>.