Introduction to Database_konsep dasar basis data.pptx

Introduction to Database-pengenalan konsep dasar pemodelan basis data

1. 01 Introduction to Database CII1J3 Database Modelling

2. Learning Outcomes Students can explain the concepts of data, data model, advantages of database approach , the process of database development life cycle, people involved in the development process, and the evolution of database system

3. Topics

4. 1. Basic Concepts and Definitions

5. Basis Data (Database)

6. Basis Data (Database) Data Data  bahan mentah Fakta mengenai objek atau informasi dasar ( angka , huruf , gambar ) yang dapat direkam dan disimpan pada media komputer Representasi tersimpan dari objek dan peristiwa yang mempunyai arti dan kepentingan dalam lingkungan pengguna . Basis Markas / Gudang, tempat berkumpul . Analogi : sebuah lemari arsip Map Kumpulan arsip dengan penomoran / pola unik tertentu  DATA Menentukan kelompok arsip .  INFORMATION Menempatkan arsip dengan kelompok tertentu  KNOWLEDGE

7. DEFINITION Beberapa definisi Database Himpunan kelompok data ( arsip ) yang saling berhubungan yang saling diorganisasi sedemikian rupa agar kelak dapat dimanfaatkan kembali dengan cepat dan mudah . Kumpulan data yang saling berhubungan yang disimpan secara bersama sedemikian rupa dan tanpa pengulangan ( redudansi ) yang tidak perlu , untuk memenuhi berbagai kebutuhan . Kumpulan data/ file/ table/ arsip yang saling berhubungan yang disimpan dalam media penyimpanan elektronis . Tabel merupakan komponen utama Pembangunan database. Kumpulan data yang terorganisis dari data yang terkait secara logis

8. Examples List of facts Data in context Useful information to some users, such as the course instructor and the registrar’s office. Figure 1. Data in context Data

9. Examples (2) Summarized Data Data presented as graphical information. This information could be used as a basis for deciding whether to add new courses or to hire new faculty members. Figure 2. Summarized Data

10. Real World facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database more facts more facts more facts more facts more facts more facts more facts more facts more facts more facts some more rather long facts about the world in the databse some more rather long facts about the world in the databse some more rather long facts about the world in the databse some more rather long facts about the world in the databse some more rather long facts about the world in the databse some more rather long facts about the world in the databse facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database facts about the world in a database Database Facts about world and behaviour of world represented in contents and operations of a database Users

11. Metadata Metadata Metadata adalah data tentang data. Metadata membantu untuk mengetahui lebih banyak tentang data itu sendiri tanpa perlu melihat atau memahami konten asli . Data yang mendeskripsikan karakteristik data dan konteks data tersebut .

12. 2. Traditional File Processing Systems

13. Traditional File Processing Systems “ Metode pengelolaan data yang mengandalkan penyimpanan dan pengolahan data dalam file-file terpisah di media penyimpanan seperti disk”  When computer-based data processing was first available, there were no databases, to be useful for business applications, computers had to store, manipulate, and retrieve large files of data.  Computer file processing systems were developed for this purpose.

14. Disadvantages of File Processing Systems Program-data dependence Duplication of data Limited Data Sharing Lengthy development times Excessive program maintenance Figure 3. Example of File Processing Systems

15. 3. The Database Approach

16. Data Models Data models is graphical systems used to capture the nature and relationships among data. Entity is a person, a place, an object, an event, or a concept in the user environment about which the organization wishes to maintain data. The data you are interested in capturing about the entity (e.g., Customer Name) is called an attribute . Data are recorded for many customers. Each customer’s information is referred to as an instance of CUSTOMER. A well-structured database establishes the relationships between entities that exist in organizational data so that desired information can be retrieved.

17. Example of Data Model Figure 4. Segment of an enterprise data model Figure 5. Segment of a project data model

18. Relational Database Relational database is a database that represents data as a collection of tables in which all data relationships are represented by common values in related tables. Relational databases establish the relationships between entities by means of common fields included in a file, called a relation

19. Database Management System (DBMS) A database management system (DBMS) is a software system that enables the use of a database approach. The primary purpose of a DBMS is to provide a systematic method of creating, updating, storing, and retrieving the data stored in a database. It enables end users and application programmers to share data, and it enables data to be shared among multiple applications rather than propagated and stored in new files for every new application (Mullins, 2002). A DBMS also provides facilities for controlling data access, enforcing data integrity, managing concurrency control, and restoring a database.

20. Advantages of DBMS Program-data independence Planned Data Redundancy Improved Data Consistency Improved Data Sharing Enforcement of Standards Improved Data Quality Increased productivity of application development Improved data accessibility and responsiveness Reduced program maintenance Improved decision support Figure 3. Example of File Processing Systems

21. Costs and Risks of the Database Approach (1) New, specialized personnel Installation and management cost and complexity Conversion costs Need for explicit backup and recovery Organizational conflict

22. Database Life Cycle

23. Database Life Cycle

24. Planning Purpose To develop a preliminary understanding of a business situation and how information systems might help solve a problem or make an opportunity possible Consist of two steps: Enterprise modelling Conceptual modelling

25. Enterprise Modelling Analyse current data processing Analyse the general business functions and their database needs Justify need for new data and databases in support of business Identify scope of database requirements for proposed information system Analyse overall data requirements for business function(s) supported by database Conceptual Data Modelling Planning

26. Analysis Purpose To analyse the business situation thoroughly to determine requirements, to structure those requirements, and to select among competing system features

27. Conceptual Data Modelling (part 2) Develop preliminary conceptual data model, including entities and relationships Compare preliminary conceptual data model with enterprise data model Develop detailed conceptual data model, including all entities, relationships, attributes, and business rules Make conceptual data model consistent with other models of information system Populate repository with all conceptual database specifications

28. Design Purpose To elicit and structure all information requirements; to develop all technology and organizational specifications Consist of two step: Logical database design Physical database design and definition

29. Logical Database Design Analyse in detail the transactions, forms, displays, and inquiries (database views) required by the business functions supported by the database Integrate database views into conceptual data model Identify data integrity and security requirements, and populate repository Define database to DBMS (often generated from repository) Decide on physical organization of data Design database processing programs Physical Database Design and Definition Design

30. Implementation Purpose To write programs, build databases, test and install the new system, train users, and finalize documentation The Steps: Code and test database processing programs Complete database documentation and training materials Install database and convert data from prior systems

31. Maintenance Purpose To monitor the operation and usefulness of the system, and to repair and enhance the system The Steps: Analyse database and database applications to ensure that evolving information requirements are met Tune database for improved performance Fix errors in database and database applications and recover database when it is contaminated

32. People Involved in Database Development

33. Managing People Involved in Database Development Business analysts Systems analysts Database analysts and data modelers Users Programmers Database architects Data administrators Project managers Other technical experts

34. Evolution of Database System

35. Evolution of Database System

36. Hierarchical Database Model In the hierarchical model, files are organized in a top-down structure that resembles a tree or genealogy chart.

37. Network Database Model In the network model, each file can be associated with an arbitrary number of other files.

38. Relational Database Model The relational model (the primary focus of this course) organizes data in the form of tables and relationships among them.

39. Object-oriented Database Model The object-oriented model is based on object classes and relationships among them. As shown in the figure, an object class encapsulates attributes and methods

40. Multidimensional Database Model Multidimensional databases, which form the basis for data warehouses, allow us to view data in the form of cubes or a star schema

41. Evolution of Database System - Resume The development and evolution of database technology generally drove by: The need to provide greater independence between programs and data, thereby reducing maintenance costs The desire to manage increasingly complex data types and structures The desire to provide easier and faster access to data for users who have neither a background in programming languages nor a detailed understanding of how data are stored in databases The need to provide ever more powerful platforms for decision support applications

42. Reference Hoffer, Jeffrey A., et.al., "Modern Database Management", Twelfth Edition, Pearson, 2016. Chapter 1

43. Questions