# The Computer Revolution/Databases/DBMS

A Database Management System is a system on your computer which allows you to access information stored in the database. They exist in different sizes and are smaller on personal computers and go on to have large systems on mainframes. The programs in the database give you the option to accumulate, modify, and retrieve information. You can request information from the DBMS as well. Examples include: ATM’s, computerized inventory systems, computerized reservation systems, and business management information.

## DBMS - Benefits

One of the most valuable benefits of DMBS databases is that it helps organizations organize, collect and manipulate information (http://audilab.bmed.mcgill.ca/~funnell/Bacon/DBMS/dbms.html). It provides structured fields, titles and tables to assist people in entering data. These databases provide structure to many organizations, fields of business and to all kinds of occupations. These databases are especially imperative in the Medical, Accounting and Human Resources fields where data input and storage is an essential part of the occupation. These databases need to be organized and easy to use in order to effectively manage. Another benefit to DMBS systems is that people within an organization can share data through this system. It is what computer experts called Centralized data (http://audilab.bmed.mcgill.ca/~funnell/Bacon/DBMS/dbms.html). Another advantage of DBMS is that information is current. If one person enters data into the system when it is saved everyone can see when the information was entered that way everyone is up to date with current events which vastly improve the communication process in organizations. The data entered into the system is kept consistent, the structure of the database allows for everyone to enter data in a manner that is the same therefore minimizing mistakes or incomplete information (http://audilab.bmed.mcgill.ca/~funnell/Bacon/DBMS/dbms.html). These central databases have improved the speed, consistency and way we deal with information which has decreased paperwork in our daily working lives.

## DBMS - Disadvantages

On most of occasions, all data is integrated into a single database. If database is damaged due to electric failure or database is corrupted on the storage media, then the valuable data may be lost forever. Another disadvantage is the complexity of this database system. It is costly, and it creates more requirements.

## DBMS - Principal Components

There are three principal components integrated into the database management system software. These will be covered in more detail in this section. The components are:
* a database dictionary,
* DBMS utilities, and
* a report generator.
First, the database dictionary does not contain actual data. It does, however, contain information to manage the data in the database, thereby enabling a database management system (DBMS) to function or access data from the database. A data dictionary may also be referred to as a “repository.” It is a file or document that is generally not made available to users, but contains a list of files in the database, the number of records in the files and names, as well as types of fields – “… data definitions and descriptions of the structure of the date used in the database” (Williams, B.K. & S.C. Sawyer, 2007, Using Information Technology: A Practical Introduction to Computers & Communications, 7th ed., Montreal: McGraw-Hill Irwin, p. 415; and http://webopedia/com/TERM/data_dictionary.html Retrieved Nov 23, 2006).
A database dictionary or repository stores descriptions of:
* data elements defined in all tables,
* tables defined in all databases,
* indexes defined for each table,
* defined databases,
* programs that access the database,
* access authorizations for all users, and
* relationships among data elements (http://webcache.googleusercontent.com/search?q=cache:ir0xLKnVB0PkJ:nsu-cc.northern.edu/MIS/MIS484/notes/CH15.ppt+DBMS+utilities&hl+en&gl+ca&ct+clnk&cd+12&client+firefox-a Retrieved Nov 23, 2006).
There are different types of data dictionaries. Included with the DBMS is the “integrated data dictionary.” A “stand-alone data dictionary” maybe available from a vendor. An “active data dictionary” has the potential to be updated by the DBMS automatically whereas the “passive data dictionary… requires a batch process to create and update the dictionary” (http://webcache.googleusercontent.com/search?q=cache:ir0xLKnVB0PkJ:nsu-cc.northern.edu/MIS/MIS484/notes/CH15.ppt+DBMS+utilities&hl+en&gl+ca&ct+clnk&cd+12&client+firefox-a Retrieved Nov 23, 2006).
The second component, DBMS utilities, is essentially for maintaining the database. These are programs that enable the user to undertake this maintenance by creating, editing and deleting the data, records and files. This component also includes automatic backup and recovery procedures (http://web.archive.org/web/20100619033849/http://www.cse.sc.edu/~holderfi/files/chap8.pdf Retrieved Nov 23, 2006). The database user can monitor the types of data being input and sort it by key fields because of DBMS utilities (Williams & Sawyer, p. 416).
The third component of a database management system (DBMS) makes the whole thing worthwhile. This program, the report generator, as the name implies, allows the user of any skill level to generate reports. It can produce on-screen or printed reports or documents from the database, or portion thereof, as specified by the user. For example, the user may specify the format as per row, column or page headers (Williams & Sawyer, p. 416 and http://web.archive.org/web/20100619033849/http://www.cse.sc.edu/~holderfi/files/chap8.pdf Retrieved Nov 23, 2006).

## DBMS - Database Administrator

Database Administrator:
It is a person who analyzes, administers, coordinates, controls and manages activities within the data administration department. Also, this person handles organization’s “database” administration and data relationship.
Database Administrator can perform a variety of activities as follow:
* Establish and enforce policies about user privacy. Database access and security
* Implement and manage configuration management approach for all database
* Implement and manage database change management processes
* Implement and manage a backup / restore strategy
* Provide proactive performance monitoring of databases.
* Monitor databases and server system configuration for performance optimization
* Install software and upgrades
* Develop a strategy to manage large data volume growth and address impacts on auditing, backups and restores
* Develop a working knowledge of applications deployed on the database
* Maintain knowledge and proficiency of current and upcoming hardware/software technologies
(retrieved December 10, 2006 from: http://jobsearch.monster.ca/getjob.asp?JobID=49483299&AVSDM=2006%2D10%2D24+12%3A51%3A50&Logo=1&cy=CA&q=Database+Administrator&lid=225&sort=rv&vw=b&dcjvlid=227)