Introducing Data Base Management Systems (DBMS): History and Data Storage Evolution

Data base management systems (DBMSs) are software packages designed to allow the entry, creation, storage, organization, querying and retrieval of data from databases. Databases collect related data or in a way that facilitates the search for information. In this modern information age, database technology has been essential to organizational productivity and at the heart of competitive advantage. Databases are relied-upon to perform and integrate several different functions: anywhere from aggregating data, tracking sales, determining compensation, prospecting opportunities, paying bills, managing customers, developing models, processing transactions, fulfilling purchases orders, etc. Good DBMSs render the manipulation and analysis of data and information easy—directly contributing to business productivity and efficiency. Conversely, poorly-conceived, built, populated and/or managed databases can be detrimental to a company and result in higher costs, inadequate customer service and/or loss of any competitive advantage, among other significant issues facing businesses today.

In a DBMS, an individual database is the collection of related attributes about entities. An entity is something of particular interest for which data is collected. Entities are represented by tables with rows and columns wherein specific data is stored in individual cells. Rows, read left to right, are referred to as records, while the columns constitute the attributes or fields. The DBMS can distinguish between records of an entity by a unique identifier called a primary key. Attributes not used as the primary key are often called secondary keys. Associations between entities can be made by implementing the primary key from one entity into the table of another entity, as such this attribute is referred to as the foreign key.


Prior to the use of DBMSs in the 1960’s, the file processing approach was used to store and manipulate data electronically. Data had widely been stored in long, sequential computer files on magnetic tape. Disk storage was expensive in the early days of computing. Data was read from flat files with application systems running in batch mode. One of the biggest issues then was the redundancy of data. Similar information often was stored in several different places or files for different reasons. Any edits made to an address for example, had to be repeated in every location the address appeared, thus creating a time-consuming, redundant job prone to human error. With falling cost of disk storage, specialized DMBS packages were first developed throughout the 1960’s for the sole purpose of managing data. Improvements ever since have focused on interface, navigation, flexibility, efficiency and usability.

Sources:
Jessup, Valadich & Wade. (2006). Information Systems Today: Why IS Matters.
Toronto: Pearson—Prentice Hall.

Ramakrishnan, R., Gehrke, J. “Database Management Systems”. Database Management Systems.
<http://pages.cs.wisc.edu/~dbbook/openAccess/thirdEdition/slides/slides3ed.html>.
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DBMS.ca. “Evolution of DBMS”. A Guide to Database Management Systems.
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Accessed April 3, 2009.