1_1_The-Database-Environment.pdf

The Database Environment MCS 104 – Database Management System I  Objectives of this Chapter Define the terminologies related to the database. Identify the limitations of the conventional file processing. Know the importance of databases. Enumerate the five categories of...

The Database Environment MCS 104 – Database Management System I  Objectives of this Chapter Define the terminologies related to the database. Identify the limitations of the conventional file processing. Know the importance of databases. Enumerate the five categories of databases. Explain advantages of databases as well as the costs and risks of using the database. List down the components of database environment. Describe evolution of database systems.  What is a Database? Storage of data An organized collection of logically related data accessed electronically from a computer system. DATA INFORMATION METADATA STRUCTURED UNSTRUCTURED DATA DATA  CLASS A Course: Bachelor of Science in Information Technology School Year: 2020 Section: 1A Semester: 1st Student ID Student Name Specialization Track GWA 2019102457 Erica Lopez Web and Mobile 1.75 2018698732 Julie Mendez Service Management 1.25 2018347156 James Reyes Web and Mobile 1.50 2020116623 Charmaine Santos Business Analytics 1.75 2019001452 Edmond Vargas Business Analytics 1.50 Context helps the users understand the data Summarized Data 1200 ENROLLMENT PROJECTION 1000 ENROLLMENT PER MAJOR (2020) Number of students 800 Service 600 Management 25% 400 Web and Mobile 45% 200 0 Business 2018 2019 2020 2021 Analytics Year 30% Graphical displays turn data into useful information that managers can use for decision making and interpretation. Example Metadata for Class A Name Type Length Min Max Description Source Course String 80 Course Name Academic Unit Section String 10 Year and Section Registrar School Year Integer 5 Academic Year Registrar Semester String 3 Academic Sem Registrar ID Integer 10 Student ID Student IS Name String 100 Student Name Student IS Specialization Track String 50 Student Major Student IS GWA Decimal 3 0.00 3.00 General Weighted Academic Unit Average Descriptions of the properties or characteristics of the data, including data types, field sizes, allowable values, and data context  Program-data All programs maintain metadata for each file they use dependence Excessive 80% of information systems budget program Duplication of Different systems/programs have maintenance data separate copies of the same data DISADVANTAGES OF FILE PROCESSING Lengthy Programmers must design their own file formats Limited data development No centralized control of data sharing times  Problems with Data Dependency Each application program must Each application program needs to Each application programmer have its own processing routines include code for the metadata of must maintain his/her own data. for reading, inserting, updating, each file. and deleting data. Lack of coordination and central Non-standard file formats. control.  Orders Department Accounting Department Payroll Department Program B Program Program Program Program Program Program A B A B A C Invoicing System Payroll System Order Filling System Inventory Customer Employee Customer Back Order Pricing File Master File Master File Master File Duplicate Data File Inventory Master File  PROBLEM: SOLUTION: DATA DATABASE Compromises REDUNDANCY Waste of APPROACH in data space integrity Central Managing repository agent Causes more Standardized Data maintenance and inconsistency headaches convenient form Requires a DBMS  Database Management System Order Filling System Invoicing System DBMS Central storage Payroll System ◼A software system that is used to create, maintain, and provide controlled access to user databases.  Advantages of the Database Approach Increased Program-data Planned data Improved data Improved data application independence redundancy consistency sharing development productivity Improved data Reduced Improved Enforcement of Improved data accessibility program standards quality and decision maintenance support responsiveness Costs and Risks of the Database Approach New, specialized personnel Installation and management cost and complexity Conversion costs Need for explicit backup and recovery Organizational conflict