Dbms Report

3581 Words Dec 7th, 2010 15 Pages
Database Management System
Introduction
A database management system is a computer based system to manage a database, or a collection databases or files. The essential word here is manage management implies the controlled use of a resource, that is controlling its quality coordinating shared use, of a resource, that is, controlling its quality, coordinating shared use and controlling access to authorized users.

A DBMS has many uses:

- it enables users to access and manipulate the database.
- it provides a building block in constructing data processing systems for applications requiring database access – MIS or systems for accounting, production and inventory control or customer support.
- it helps the DBA perform certain
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Originally DBMSs were found only in large organizations with the computer hardware needed to support large data sets.

1960s Navigational DBMS

As computers grew in capability, this trade-off became increasingly unnecessary and a number of general-purpose database systems emerged; by the mid-1960s there were a number of such systems in commercial use. Interest in a standard began to grow, and Charles Bachman, author of one such product, Integrated Data Store (IDS), founded the "Database Task Group" within CODASYL, the group responsible for the creation and standardization of COBOL. In 1971 they delivered their standard, which generally became known as the "Codasyl approach", and soon there were a number of commercial products based on it available.

The Codasyl approach was based on the "manual" navigation of a linked data set which was formed into a large network. When the database was first opened, the program was handed back a link to the first record in the database, which also contained pointers to other pieces of data. To find any particular record the programmer had to step through these pointers one at a time until the required record was returned. Simple queries like "find all the people in India" required the program to walk the entire data set and collect the matching results. There was, essentially, no concept of "find" or "search". This might sound like a serious limitation today, but in an era when the data was
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