Database Management and it is definition

Data Management, Type and Definition of Database, Problems of File Processing in Traditional System,

1. Database Management Chapter # 4 Abdul Rashed Barakzai

2. Introduction Just imagine how difficult it would be to get any information from a system if data were stored unorganized: In Information system data resource must be organized, and structure in some logical manner It help to access or process data efficiently, retrieve quickly Data structures methods can me simple or complex In todays word data are organized and stored some where in Database The question is not “ should I use a database” but rather “ what database should I use”

3. Data Management Data may be organized base on: Characters Field Record Database Example: writing can be organized base on letter, words, sentence , paragraph and document.

4. Continue… 1. Character: This is the basic logical data element It is consist of single alphabetic, numeric or other symbol Characters is the most basic element of Data that can be observed and manipulated 2. Field: It is the higher level od data It is consists of a grouping of related characters Example: Group of alphabetic characters in a persons name Data field represent attribute ( a characteristic or quality) of a some entity ( object, person, place or event) Example: An employee salary is an attribute that is typical a field use to describe an entity who is an emplyee

5. Continue… 3. Record: All field used to describe the attributes of an entity are grouped to form a record Record represents a collection of attributes that describe a single instance of an entity. Example: Payroll Record which consists of data 2. Database: A database is an integrated collection of logically related data elements.

6. What is Database? A  database  is an organized collection of structured information, or data, typically stored electronically in a computer system. A  database  is usually controlled by a  database  management system (DBMS). Most  databases  use structured query language (SQL) for writing and querying data.

7. Types of Database Operational Database: Store detailed data needed to support the business process and operation of a company They are also called subject area database, Transaction database or Production Database base Distributed Database: Many Organization replicate and distribute copies or parts of database to network servers at a variety of sites. Distributed database can reside on network server on the WWW It may copies of operation al or analytical database, hypermedia or discussion database

8. Database Management System A database management system (DBMS) is the main software tool of the database management approach because it controls the creation, maintenance, and use of the databases of an organization and its end users. Microcomputer database management packages such as Microsoft Access, Lotus Approach, or Corel Paradox allow you to set up and manage databases on your PC, network server, or the World Wide Web. In mainframe and server computer systems, the database management system is an important system software package that controls the development, use, and maintenance of the databases of computer-using organizations

9. Problems of File Processing in Traditional System The file processing approach finally became too cumbersome, costly, and inflexible to supply the information needed to manage modern business and, as we shall soon see, was replaced by the database management approach . Despite their apparent logic and simplicity,

10. Problems of File Processing Data Redundancy: Independent data files included a lot of duplicated (such as a customer’s name and address) were recorded and stored in several files. This data redundancy caused problems when data had to be updated. Separate file maintenance programs had to be developed and coordinated to ensure that each file was properly updated. Of course, this coordination proved difficult in practice, so a lot of inconsistency occurred among data stored in separate files.

11. Problems of File Processing 2. Lack of Data Integration: Having data in independent files made it difficult to provide end users with information for ad hoc requests that required accessing data stored in several different files. Special computer programs had to be written to retrieve data from each independent file. This retrieval was so difficult, time-consuming, and costly for some organizations that it was impossible to provide end users or management with such information. End users had to extract the required information manually from the various reports produced by each separate application and then prepare customized reports for management.

12. Problems of File Processing 3. Data Dependence: In file processing systems, major components of a system the organization of files, their physical locations on storage hardware, and the application software used to access those files depended on one another in significant ways. For example, application programs typically contained references to the specific format of the data stored in the files they used. Thus, changes in the format and structure of data and records in a file required that changes be made to all of the programs that used that file. This program maintenance effort was a major burden of file processing systems. It proved difficult to do properly, and it resulted in a lot of inconsistency in he data files.

13. Problems of File Processing 4. Lack of Data Integrity or Standardization: In file processing systems, it was easy for data elements such as stock numbers and customer addresses to be defined differently by different end users and applications. This divergence caused serious inconsistency problems in the development of programs to access such data. In addition, the integrity (i.e., the accuracy and completeness) of the data was suspect because there was no control over their use and maintenance by authorized end users. Thus, a lack of standards caused major problems in application program development and maintenance, as well as in the security and integrity of the data files needed by the organization.