Friday, April 3, 2009

History of DBMS



Introduction



A DBMS (Database management system) is used to create and maintain the structure of a database, and then to enter, manipulate and retrieve the data it stores. Creating an efficient database design is the key to effectively using a database to support an organization's business operations(1). A database management system (DBMS) is a computer software that manages databases, it may use any of a variety of database models, such as the hierarchical DBMS, network DBMS and relational DBMS . In large systems, a DBMS allows users and other software to store and retrieve data in a structured way.(2)


History


1960's-1970's: The emergence of the first type of DBMS, the hierarchical DBMS. IBM had the first model, developed on IBM 360 and their (DBMS) was called IMS, originally it was written for the Apollo program. This type of DBMS was based on binary trees, where the shape was like a tree and relations were only limited between parent and child records. The benefits were numerous; less redundant data, data independence, security and integrity, which all lead to efficient searches. Nonetheless; there were some disadvantages such as; complex implementation, was hard to manage because of the absence of standards, which made it harder to handle many relationships.( see image below) (1)(3)

1960's-1970's: The emergence of the network DBMS. Charles Bachmann developed first DBMS at Honeywell, Integrated Data Store ( IDS) then a group called CODASYL who is responsible for the creation of COBOL, had that system standardized. However; the CODASYL group invented what they call the "CODASYL APPROACH. Based on that approach many systems using network DBMS were developed for business use(2). In this model, each record can have multiple parents in comparison with one in the hierarchical DBMS. It is made of sets of relationships where a set represents a one to many relationship between the owner and the member. The main and unfortunate disadvantage was that the System was complex and there was difficulty in design and maintenance, it is believed that the Lack of structural independence was the main cause. (2)(3)

1970's- 1990's: The emergence of the relational DBMS on the hands of Edgar Codd. He worked at IBM, and he was unhappy with the navigational model of the CODASYL APPROACH. To him, a tool for searching, such as a search facility was very useful, and it was absent . In 1970, he proposed a new approach to database construction, which made the creation of a Relational DBMS intended for Large Shared Data Banks, possible and easy to grab (3). Moreover; This was a new system for entering data and working with big databases, where the idea was to use a table of records. All tables will be then linked by either one to one relationships, one to many, or many to many(2). when elements took space and were not useful, it was easy to remove them from the original table, and all the other "entries" in other tables linked to this record were removed. Worth mentioning, is that two initial projects were launched, the R program at IBM, and INGRES program at the university of California. In 1985, the object oriented DBMS was developed, but it did not have any booming commercial profit because of the high unjustified costs to change systems, and format. In 1990, the DBMS took on a new object oriented approach joint with relational DBMS . In this approach, text, multimedia, internet and web use in conjunction with DBMS were available and possible.(3)(1)

Past and present

In the early years of computing, a punch card was used in unit record machines for input, data storage and processing this data. Data was entered offline and for both data, and computer programs input. This input method is similar to voting machines nowadays (2). This was the only method, where it was fast to enter data, and retrieve it, but not to manipulate or edit it.
After that era, there was the introduction of the file type entries for data, then the DBMS as hierarchical, network, and relational.(3)




















(4)



(1) ORACLE 9I SQL ( LANNES L. MORRIS-MURPHY)
(2) WIKIPEDIA : DBMS
(3) http://www.comphist.org/computing_history/new_page_9.htm
(4)(pic ref): http://ww2.cis.temple.edu/cis109friedman/CIS%20109%20-%20Lecture%20Set%20I%20-%20Introduction%20and%20Overview/history.gif

2 comments:

  1. this is wonder collection of knowledge..............

    ReplyDelete
  2. I really like the history of how DBMS came about!

    ReplyDelete