Topic-1.docx

**Unit 1** **THE DATABASE ENVIRONMENT** Human beings began to store information very long ago. In the ancient times, elaborate database systems were developed by government offices, libraries, hospitals, and business organizations, and some of the basic principles of these systems are still being...

**Unit 1** **THE DATABASE ENVIRONMENT** Human beings began to store information very long ago. In the ancient times, elaborate database systems were developed by government offices, libraries, hospitals, and business organizations, and some of the basic principles of these systems are still being used today. A Database Management System allows a person to organize, store, and retrieve data from a computer. It is a way of communicating with a computer's "stored memory." But before a person can design his or her own database based on user requirements, one must first know the basic concepts of what he or she is about to use later on. This unit is designed to discuss the basic concepts and terminologies of the Database Management System as well as its approaches and its functions. In this way, you come to understand better the significance of database in our daily living. a. **Identify and understand the different terminologies in Database Management System.** b. **Explain the advantages and Disadvantages of database systems and DBMS Approach** c. **Identify and discuss the different functions of Database Management System** d. **Demonstrate appreciation on the significance and functions of database to a man.** a. Define and identify Database Management System and other related terminologies; b. Differentiate traditional file processing and database approach; and c. Enumerate and discuss the components of Database Environment. **What is a database?** ----------------- ------------------- ----------------------- **K** **W** **L** (What You Know) (What You want to (What You Learned and Learn) still Want to Learn) ----------------- ------------------- ----------------------- **BACKGROUND** Information Management (IM) is a cycle of processes that support the organization\'s learning activities: identifying information needs, acquiring information, organizing and storing information, developing information products and services, distributing information, and using information. In computer science, IM focuses on the structures underlying quantitative data and their relationship to the design of databases. Databases and database systems are an essential component of life in modern society. For example, if we go to the bank to deposit or withdraw funds, if we make a hotel or airline reservation, if we access a computerized library catalog to search for a bibliographic item, or if we purchase something online---such as a book, toy, or computer---chances are that our activities will involve someone or some computer program accessing a database. Even purchasing items at a supermarket often automatically updates the database that holds the inventory of grocery items. **HISTORY** The origins of the database go back to libraries, governmental, business and medical records before the computers were invented. Once people realized they needed to have the means to store data and maintain the data files for later retrieval, they were trying to find ways to store, index and retrieve data. With the emergence of computers, the world of the database changed rapidly, making it an easy, cost effective, and less space-consuming task to collect and maintain the database. **BASIC CONCEPTS AND TERMINOLOGIES** **Database** It is basically just computerize record keeping system and can be regarded as an electronic filing cabinet. -a shared collection of logically related data, designed to meet the information needs of multiple users. \- A database may be of any size and complexity. - Databases today are used to store objects such as documents, photographic images, sound, and even video segments, in addition to conventional textual and numeric data. - In addition to storing data, you can also sort, extract, and summarize information related to the data. **Data** -refers to the raw facts concerning people, objects, events or other entities. - Historically, the term *data* referred to known as facts that could be recorded and stored in a computer media. **-Since databases today are used to store objects such as documents, photographic images, sound and even video segments, in addition to textual and numerical data. To reflect this reality, the definition of data now is:** **- Consists of facts, text, graphics, images, sound and video segments that have meaning in the user's environment.** **Baker, Kenetth 324917628** **Doyle, Joan 467231428** **Finkle, Clive 123456789** **Lewis, John 987654312** **McFerran, Debra 873548179** **Information** -data that have been processed and presented in a form of suitable for human interpretation, often with the purpose of revealing trends or patterns. - The terms *data* and *information* are closely related and in fact are often used interchangeably. However, it is often useful to distinguish between *data* and *information.* - Data that has been processed in such a way that it can increase the knowledge of the person who uses it. - Another way to convert data into information is to summarize them or otherwise process and present them for human interpretation. - For example: A summarized student enrollment data presented as graphical information. EXAMPLE: Summarized Data Data in Context **Meta-data** **-**overall information about the single information -information about the data in an organization -"Data about data" \- These are data that describe the properties or characteristics of other data. Some of these properties include data definitions, data structures and rules or constraints. - Some sample metadata for the Class Roster are listed in Table 1.1 - For each data item that appears in the Class Roster, the metadata show the data item, the data type, length, minimum and maximum allowable values and brief description of each data item. -Descriptions of the properties or characteristics of the data, including data types, field sizes, allowable values, and documentation. -Distinction between data and metadata: Metadata is once removed from data. That is, metadata describe the properties of data but do not include that data. **Traditional File Processing** - In the beginning of computer-based data processing, there were no databases. Computers were used almost exclusively for scientific engineering calculations. - To be useful for business applications, computers must be able to store, manipulate and retrieve large files of data. Computer file processing systems were developed for this purpose. - In file system approach, each user defines and implements the needed files for a specific application to run. - For example in sales department of an enterprise, One user will be maintaining the details of how many sales personnel are there in the sales department and their grades, these details will be stored and maintained in a separate file. - Another user will be maintaining the salesperson salary details working in the concern, the detailed salary report will be stored and maintained in a separate file. Although both of the users are interested in the data's of the salespersons they will be having their details in a separate file and they need different programs to manipulate their files. **Disadvantages:** **Program-data Dependence** - All programs maintain metadata for each file they use. - File descriptions are stored within each application program that access a given file. **Duplication of data or Data Redundancy** - Since applications are often developed independently in file processing systems, unplanned duplicate data files are the rule rather than the exception. - Duplicate data files often result in loss of data integrity since either the data formats may be inconsistent or data values may not agree (or both). - Different systems/programs have separate copies of the same data **Limited Data Sharing** - With the traditional file processing approach, each application has its own private files and users have little opportunity to share data outside their own applications. - No centralized control of data. **Lengthy Development Times** - There is little opportunity to leverage previous development efforts. - Each new application requires that the developer essentially start from scratch by designing new file formats and descriptions. **Excessive Program Maintenance** - As much as 80% of the total information systems developed budget may be devoted to program maintenance in such organizations. **Database Approach** **-**simply uses database to manage all data and information (as a whole). - It emphasizes the integration and sharing of data throughout the organization. - In Database approach, data is managed by a controlling agent and stored in a standardized, convenient form. - This approach requires a fundamental re orientation or shift in thought process, starting with top management. **Database Management System (DBMS)** - is a collection of programs that enables users to create and maintain a database. It is a general-purpose software system that facilitates the processes of defining, constructing, manipulating, and sharing databases among various users and applications. - It stores data in such a way that it becomes easier to retrieve, manipulate, and produce information. **ELEMENTS OF DATABASE APPROACH** **Enterprise Data Model** -a map or graphical model that shows the entities and the relationship among them. **Enterprise resource planning (ERP)** **Enterprise resource planning** is a term originally derived from manufacturing resource planning (MRP II) that followed material requirements planning (MRP). ERP systems typically handle the manufacturing, logistics, distribution, inventory, shipping, invoicing, and accounting for a company. ERP software can aid in the control of many business activities, including sales, marketing, delivery, billing, production, inventory management, quality management and human resource management. **Relational Databases** - Database technology involving tables (relations) representing entities and primary/foreign keys representing relationships **Database Applications** - It is an application program (or set of related programs) that is used to perform a series of activities on behalf of database users. - Each database application performs some combination of the following basic operations. - Create -- Add new data to the database. - Read -- Read current database data. - Update -- Update or modify current database data - Delete -- Delete current data from the database. **Database application system** includes the data definitions, stored data, transactions, inquiries, and reports needed to capture, maintain and present data from a database.