Objectives:-
>Define the term, database, and explain how a database interacts with data and information.
>Define the term, data integrity, and describe the qualities of valuable information.
>Discuss the terms character, field, record, and file.
>Describe file maintenance techniques and validation techniques.
>Differentiate between a file processing approach and the database approach.
>Discuss the functions common to most database management systems.
>Describe characteristics of relational, object-oriented, and multidimensional databases.
>Explain how to access Web databases.
>Identify database design guidelines and discuss the responsibilities of database analysts and administrators.
Databases,Data and Information:-
Database
>Collection of data organized in a manner that allows access, retrieval, and use of that data.
Data
>Collection of unprocessed items
*Text *Numbers *Images *Audio *Video
Information
>Processed data
*Documents *Audio *Images *Video
>Database software, often called a database management system (DBMS), allows users to:
*Create a computerized database.
*Add, modify, and delete data.
*Sort and retrieve data.
*Create forms and reports from the data.
>Data integrity identifies the quality of the data.
>Garbage in, garbage out (GIGO) points out the accuracy of a computer’s output depends on the accuracy of the input.
>Valuable information should have the following characteristics:-
*Accurate.
*Verifiable.
*Timely.
*Organized.
*Accessible.
*Useful.
*Cost-effective.
Hierarchy of Data:-
>A character is one byte.
*numbers, letters, space, punctuation marks, or other symbols
>A field is a combination of one or more related characters.
*Field name.
*Field size.
*Data type.
Maintaining Data :-
>File maintenance refers to the procedures that keep data current.
*Adding records.
*Modifying records.
*Deleting records.
>Validation compares data with a set of rules or values to find out if the data is correct.
File Processing versus Databases:-
File processing system
*Each department has its own set of files.
*Used for many years.
*Have data redundancy.
*Isolate data.
Database approach
*Programs and users share data.
*Reduce data redundancy.
*Improve data integrity.
*Share data.
*Allows easier access.
*Reduces development time.
*Can be more vulnerable.
Database Management Systems:-
>A data dictionary contains data about each file in the database and each field in those files.
>A DBMS provides several tools that allow users and programs to retrieve and maintain data in the database.
>A query language consists of simple, English-like statements that allow users to specify the data to display, print, or store.
>Query by example (QBE) provides a GUI to assist users with retrieving data.
>A form is a window on the screen that provides areas for entering or modifying data in a database.
>A report generator allows users to design a report on the screen, retrieve data into the report design, and then display or print the report.
Relational, Object-Oriented, and Multidimensional Databases:-
>A data model consists of rules and standards that define how the database organizes data.
>A relational database stores data in tables that consist of rows and columns.
*Each row has a primary key.
*Each column has a unique name.
>A relationship is a link within the data.
>Structured Query Language (SQL) is a query language that allows users to manage, update, and retrieve data.
>An object-oriented database (OODB) stores data in objects
>Examples of applications appropriate for an object-oriented database include:-
*Multimedia database.
*Groupware database.
*Computer-aided design database.
*Hypertext database.
>A multidimensional database can store data in more than two dimensions of data.
*Sometimes known as a hypercube.
*Can consolidate data much faster than a relational database.
>A data warehouse is a huge database that stores and manages the data required to analyze historical and current transactions.
Database Administration :-
>Employees should learn how to use the data in the database effectively.
*Interact with database.
*Identify new data for the database.
*Maintain the database.
Summary :-
*How data and information are valuable assets to an organization.
*Methods for maintaining high-quality data.
*Assessing the quality of valuable information.
*Advantages of organizing data in a database.
*Various types of databases.
*Roles of the database analysts and administrators.
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