Database overview unit 4 part 1

Database overview unit 4 part 1

• 1.
  Database Overview 1
• 2.
  Outline Database ◦ What isDatabase ◦ Why to design database ◦ How to meet the user’s need Evolution of Database ◦ File System ◦ Data Models ◦ Hierarchical ◦ Network ◦ Relational ◦ Entity-Relationship ◦ Object-Oriented ◦ Web Database 2
• 3.
  Database: What Database ◦ iscollection of related data and its metadata organized in a structured format ◦ for optimized information management Database Management System (DBMS) ◦ is a software that enables easy creation, access, and modification of databases ◦ for efficient and effective database management Database System ◦ is an integrated system of hardware, software, people, procedures, and data ◦ that define and regulate the collection, storage, management, and use of data within a database environment 3
• 4.
  Database Management System 4 DatabaseSystems: Overview of an Organization - End users and database : managed by the database application
• 5.
  Database System Environment 5 DatabaseSystems: Example of Database system of an Organization  Hardware  CPU, Memory  Software - OS - DBMS - Applications  People : User’s  Procedures  Data
• 6.
  Database: Why Purpose ofDatabase ◦ Optimizes data management ◦ Transforms data into information Importance of Database Design ◦ Defines the database’s expected use ◦ different approach needed for different types of databases ◦ Avoid data redundancy & ensure data integrity ◦ data is accurate and verifiable ◦ Poorly designed database generates errors ◦ leads to bad decisions ◦ can lead to failure of organization Functions of DBMS/Database System ◦ Stores data and related data entry forms, report definitions, etc. ◦ Hides the complexities of relational database model from the user ◦ facilitates the construction/definition of data elements and their relationships ◦ enables data transformation and presentation ◦ Enforces data integrity ◦ Implements data security management ◦ access, privacy, backup & restoration 6
• 7.
  Database: How Planning &Analysis ◦ Assess ◦ Goal of the organization ◦ Database environment ◦ existing hardware, software, raw data, data processing procedures ◦ Identify ◦ Database needs ◦ what database can do to further the goal of the organization ◦ User needs and characteristics ◦ who the users are, what they want to do, how they envision doing it ◦ Database system requirements ◦ what the database system should do to satisfy the database and user needs Design ◦ From conceptual design to a detailed system specification Implementation ◦ Create the database Maintenance ◦ Troubleshoot, update, streamline the database 7
• 8.
  Business Rules What ◦ Brief,precise, and unambiguous descriptions of operations in an organization ◦ based on policies, procedures, or principles within a specific organization ◦ help to create and enforce actions within that organization’s environment ◦ apply to any organization that stores and uses data to generate information Why ◦ Enhance understanding & facilitate communication ◦ Standardize company’s view of data ◦ Constitute a communications tool between users and designers ◦ Allow designer to understand business process as well as the nature, role, and scope of data ◦ Promote creation of an accurate data model How (sources) ◦ Interviews ◦ Company managers ◦ Policy makers ◦ Department managers ◦ End users ◦ Written documentation ◦ Procedures, Standards, Operations manuals ◦ Observation ◦ Business operations 8
• 9.
  Database: User-centered Perspective ◦ Theuser is always right. If there is a problem with the use of the system, the system is the problem, not the user. Compliance ◦ The user has the right to a system that performs exactly as promised. Instruction ◦ The user has the right to easy-to-use instructions (user guides, online or contextual help, error messages) for understanding and utilizing a system to achieve desired goals and recover efficiently and gracefully from problem situations. Usability ◦ The user should be the master of software and hardware technology, not vice- versa. Products should be natural and intuitive to use. 9
• 10.
  Database: Data Models Importance ◦Abstraction of complex real-world data structures in relative simple (graphical) representations ◦ Facilitate interaction among the designer, the applications programmer, and the end user Basic Building Blocks ◦ Entity ◦ thing about which data are to be collected and stored ◦ Attribute ◦ a characteristic of an entity ◦ Relationship ◦ describes an association among entities ◦ Constraint ◦ restrictions placed on the data 10