Database Management Systems (DBMS)

7 Mar

Hey Guys,

In my last blog I showed you guys why databases were better than the older file-processing approach and I said that in my next blog I will discuss Database Management Systems with you guys so here it is:

First of all a DBMS is used to create, access, control and manage the databases. It provides logical access to the data stored in the database so that users and programmers do not have to worry about the physical aspects of the database.

There are four main functions of DBMS which are

1. Database Development

  • Create database, tables and supporting structures (e.g primary keys, relationships)
  • Enforce rules

2. Database Maintenance

  • Maintain database structures (e.g alter, drop, truncate tables) 

3. Database Interrogation/Manipulation

  • Add, change, delete data from database
  • Retrieve data from database

4. Application Development

  • Facilities to help develop applications using forms for data entry/enquiry
  • Create reports based on certain criteria
  • Appropriate SQL generated in the background

There are also several other functions of DBMS which include:

  • Backup and Recovery 
  • Security Management
  • Query optimisation
  • Concurrency Control

 

The language used by DBMS is

  • Structured Query Language (SQL)
  • Type SQL at command level interface prompt or
  • use DBMS interface (e.g Microsoft Access user tools) for generation SQL

 

Metadata stored in the Data Dictionary

Metadata in the data dictionary describes each piece of data in a business and describes in detail the characteristics of the data, including:

  • Size of the data (how many bytes)
  • Range of acceptable values for each field (e.g 1-100)
  • Type of data (e.g number, character, audio, etc.)
  • Ownership (who has the right to view or modify the data)

Here is just a small diagram that might help your understanding of DBMS

Thanks for reading hope ye liked it

 

References:

Dr. Audrey Grace

 

 

 

 

 

One Response to “Database Management Systems (DBMS)”

  1. sad111708665 March 8, 2013 at 8:02 pm #

    …nicely structured blog; thanks for the info on DBMS🙂

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