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Purpose of DBMS and users of DBMS

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Purpose of DBMS and users of DBMS

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Purpose of DBMS and users of DBMS

  1. 1. Purpose & Users of DBMS
  2. 2. Index 1. Introduction of DBMS 2. Purpose of DBMS 1) Data Redundancy 2) Inconsistency 3) Difficulties in accessing data 4) Data isolation 5) Integrity Problem 6) Atomicity Problem 7) Concurrent Access Anomalies 8) Security Problem 3. Users of DBMS 1) Naive Users 2) Application Programmers 3) Sophisticated Users 4) Specialized Users
  3. 3. Introduction of DBMS Database: Collection of interrelated data and Some programs to access those data. Database Management System: Software Designed to assist in maintaining and utilizing large collection of Data.
  4. 4. Purpose of DBMS
  5. 5. Data Redundancy  Data can appear multiple times in a database for variety of reasons. These is called Data redundancy.  It results into wastage of storage space  Decreases efficiency of database  May cause data corruption  DBMS prevents this issue from taking place.
  6. 6. Data Inconsistency  Redundancy leads to higher storage and access cost.  Inconsistency is really corollary of Redundancy.  Various copies of same data may no longer agree. It’s called Inconsistency.  Leads to incorrect data supply.
  7. 7. Difficulties in accessing data  In typical file-processing system , permanent records are stored in various files.  Which makes accessing data very difficult.  Where as in DBMS data can be be accessed in seconds.  The point here is that conventional file-processing environments do not allow needed data to be retrieved in a convenient and efficient manner.  Moreresponsive data-retrieval systems are required for general use.
  8. 8. Data isolation  In conventional file-processing system data is stored in different formats.  It was difficult to write new application programs in file- processing system .  Only at that time the concept of DBMS emerges for the rescue of a large number of organizations.
  9. 9. Integrity Problem  The data values stored in the database must satisfy certain types of consistency constraints.  In conventional file-processing system constraints cannot be applied .  Suppose also that the university requires that the account balance of a department may never fall below zero.  It can be done in DBMS enforcing these constraints in the system by adding appropriate code in the various application programs.
  10. 10. Atomicity Problem  A computer system, like any other device, is subject to failure.  Clearly, it is essential to database consistency that either both the credit and debit occur, or that neither occur.  That is, the funds transfer must be atomic—it must happen in its entirety or not at all.  It is difficult to ensure atomicity in a conventional file- processing system.
  11. 11. Concurrent Access Anomalies  There may be a possibility that two users are maintaining same files data for different applications.  Anomalies occur when changes made by one user gets lost because of changes made by other user.  So DBMS helps to prevent Concurrent Access Anomalies in data.
  12. 12. Security Problem  Data security means prevention of data accession by unauthorized users.  conventional file-processing system don’t have any security measures.  Wheres DBMS has features of data security to protect data from unauthorized users.
  13. 13. users  Naïve : Any user who does not have any knowledge about database can be in this category.  Application Programmers : application programmers are the one who writes application programs that uses the database.  Sophisticated Users - They are database developers, who write SQL queries to select/insert/delete/update data.  Specialized Users : The sophisticated users who write special database application programs are called specialized users. The write complex programs for the specific complex requirements.

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