1. 1 Chapter 2 Database Environment Transparencies Last Updated: Pebruari 2010 By M. Arief Updated by RSO Feb 2011 http://arief.ismy.web.id

2. 2 Chapter 2 - Objectives ► Database architecture. ► Database languages ► Data Model ► Database functions http://arief.ismy.web.id

3. 3 ANSI -SPARC Three-Level Architecture http://arief.ismy.web.id

4. 4 Objectives of Database Architecture ► All users should be able to access same data but have a different customized view of the data ► Users should not need to know physical database storage details. ► DBA should be able to change database storage structures without affecting the users’ views. http://arief.ismy.web.id

5. 5 ► Internal structure of database should be unaffected by changes to physical aspects of storage. ► DBA should be able to change conceptual structure of database without affecting all users. http://arief.ismy.web.id Objectives of Database Architecture

6. -NIM -Name -Address -CourseCode -CourseName -CourseCredit -NIM -Semester -CourseCode NIMNameSemesterCourseCodeCourse NameCredits Semester NIM Course CodeCourse NameCreditsFees Name Credits x fee External Schema Conceptual Schema Internal Schema External/Conceptual Mapping Conceptual/ Internal Mapping EXTERNAL LEVEL INTERNAL LEVEL CONCEPTUAL LEVEL

7. 7 ANSI-SPARC Three-Level Architecture ► External Level  Users’ view of the database.  Describes that part of database that is relevant to a particular user. ► Conceptual Level  Community view of the database.  Describes what data is stored in database and relationships among the data. http://arief.ismy.web.id

8. 8 ANSI-SPARC Three-Level Architecture ► Internal Level  Physical representation of the database on the computer.  Describes how the data is stored in the database. http://arief.ismy.web.id

9. 9 Data Independence ► Logical Data Independence  Refers to immunity of external schemas to changes in conceptual schema.  Conceptual schema changes (e.g. addition/removal of entities).  Should not require changes to external schema or rewrites of application programs. http://arief.ismy.web.id

10. 10 Data Independence ► Physical Data Independence  Refers to immunity of conceptual schema to changes in the internal schema.  Internal schema changes (e.g. using different file organizations, storage structures/devices).  Should not require change to conceptual or external schemas. http://arief.ismy.web.id

11. 2. Database Languages ► There are two languages works in DBMS, which are host languages and sublanguages. ► Host languages are high-level programming languages such as C, C++, C#, Java, VB, etc. ► Sublanguages are languages which exclude conditional and iterative provided by those host languages. DBMS has two sublanguages consisting of Data Definition Language (DDL) and Data Manipulation Language (DML). 11

12. 12 Data Definition Language (DDL)  DDL is used to specify the database schema,  DDL allows the DBA or user to describe and name entities, attributes, and relationships required for the application plus any associated integrity and security constraints. http://arief.ismy.web.id

13. 13 Data Manipulation Language (DML)  DML is used to both read and update the database.  DML provides basic data manipulation operations on data held in the database. ► Procedural DML  allows user to specify what data is needed and how to retrieve the data  Allow users to specify how the output of DML should be obtained  Operates on records individually ► Non-Procedural DML  allows user to specify what data is needed regardless how to retrieve the data  Allow users to specify what the output of DML should be obtained  Operates on a set of records http://arief.ismy.web.id

14. 14 Host Languages ► Fourth Generation Language (4GL)  Requires fewer lines  Non-procedural  The user defines parameters, not the steps  Improve productivity http://arief.ismy.web.id

15. 15 4GL  Forms Generators: data inputs & layout  Report Generators: reports  Graphics Generators: graph  Application Generators: programs & interfaces with database http://arief.ismy.web.id

16. 16 Data Model Data Model is an integrated collection of concepts for describing data, relationships between data, and constraints on the data in an organization. ► Data Model comprises:  a structural part: rules for constructing DB  a manipulative part: rules for changing DB  a set of integrity constraints: rules for data accuracy http://arief.ismy.web.id

17. Data Model refers to ANSI SPARC Architecture ► External Data Model  record based model & object based model ► Conceptual Data Model  record based model & object based model ► Internal Data Model  physical data model 17

18. 18 Record-Based-Data Models  Relational Data Model: Related tables  Network Data Model: Related records  Hierarchical Data Model: Tree structured records http://arief.ismy.web.id

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22. Object-Based Data Models  Entity-Relationship  Semantic  Functional  Object-Oriented (chapter 27-29) 22

23. Entity Relationship Model 23 StudentsKRS take NIMName Course Code Course Name

24. Semantic Relationship Model 24 NIMName Course Code Course Name take Students KRS

25. Functional Relationship Model 25 intstringintstring take Students KRS NIMCourse NameCourse CodeName

26. Individual Homework ► 2 most common of physical data model are unifying model and frame memory. ► Compare these 2 data models 26

27. 27 Functions of a DBMS by Codd (1982) ► Data storage, retrieval and update: DBMS can store, retrieve, and update data ► A user accessible catalog: DBMS provides a catalog which contains descriptions of data ► Transaction support: DBMS makes sure all updates are processed or ignored ► Concurrency control services: DBMS makes sure database is updated correctly although it’s being used by multi users ► Recovery services: DBMS can recover database from damages http://arief.ismy.web.id

28. 28 Functions of a DBMS ► Authorization services: DBMS allows authorized users only ► Support for data communication: DBMS can integrate with communication software ► Integrity services: DBMS follows certain rules in updating database ► Service to promote data independence: DBMS facilitates data independence ► Utility services: DBMS provides a set of utilities http://arief.ismy.web.id

29. Tugas Group ► Membuat aplikasi computer untuk data entry & maintenance pada unit bisnis tertentu. ► Aplikasi meng-cover 1 unit/proses business lengkap sesuai topicnya ► Aplikasi komputer bebas. ► Dikumpulkan 1 minggu sebelum Kelas terakhir! ► Isi paper: ► 1. Pendahuluan ► 2. Business Proses ► 3. Logical,Conceptual,&Physical Design ► 4. Aplikasi Design ► 5. Diskusi ► 6. Kesimpulan ► 7. Lampiran 29

30. Tugas Group-Topik ► Perpustakaan (peminjaman, pengembalian, etc) ► Persewaan Kendaraan (Mobil, alat berat, etc) ► Hotel (booking, reservasi, etc) ► Parkir ► Ticketing (pesawat, ka, kapal laut, etc) ► HRD (penggajian, etc) ► Toko ► Gudang ► Asuransi (perhitungan premi, claim premi, etc) ► Bank (kartu kredit, buku tabungam, etc) ► Club (Golf, etc) ► Café (Coffee shop, internet café, etc) ► Travel (schedule, etc) ► Healt Care (Hospital, Dokter, Dokter gigi, etc) ► Manufacturing (plan,produksi, etc) ► Kirimkan ke raymond@unimedia.ac.id subject “TI-403/Nama Kelas/Nama Ketua Kelompok/HAL” raymond@unimedia.ac.id 30