Matakuliah Tahun Versi : M0174/OBJECT ORIENTED DATABASE : 2005 : 1/0 Pertemuan 1 Database Approach 1 Learning Outcomes Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu : • Mahasiswa dapat Menjelaskan penerapan penggunaan dan konsep data model dari generasi teknologi database (C2) 2 Outline Materi • • • • The Organization Data and information An organization's database File oriented system vs dbms 3 The Organization • A database system exists to provide an organization with the information system necessary for it to carry out its activities. • An organization is a very general term which refers to “any organized body or system or society”, and the database approach is applicable to organizations in general 4 Data and information • What is data ? • What is information ? • Examples 5 An organization's database • Computer program are used to assist people to carry out many of the activities that enable organization of all type to operate effectively • To do this these application program will usually have to access stored information about organization and environments 6 An organization's database • Information about organization and environments is usually represented within computer as data which is stored as data file on storage device. • Database Management System(DBMS) is a particular type of computer program which is used by application program to manage and provide access to the stored data 7 An organization's database • The collection of data managed by a DBMS is called a Database. • Examples 8 File oriented system vs dbms • File-Oriented Systems – The traditional (pre-database technology) approach, database exist as a collection of files – Here we have file are recorded details of information about organization and environment – The application program inputs data, check the new data is valid, and updates appropriate files. 9 File oriented system vs dbms • Two characteristic of file-oriented system – Data files are organized for convenience of specific programs. – Programs must have built into them knowledge of how files are organized, the ways in which records can be accessed, and the meaning of the data. 10 File oriented system vs dbms • That characteristic have two undesirable consequences – File-Oriented computer system are likely to be unstable. – Management of data can be difficult. Data may be distributed across a number of files to be accessed by different application programs 11 File oriented system vs dbms • Database Approach – The database approach to computerizing information activities is to treat the organization data as a resource which is shared by all relevant application program. – The data is made shareable by structuring in it such a way that it has the same structure as the information that it represents 12 File oriented system vs dbms – Application programs can then be programmed to access the logical structures of the information that is processed, rather than the structure of files that are used to store the data that represent it 13 File oriented system vs dbms • The general objective of the database approach: “A database should be a natural representation of information as data, with few imposed restrictions, capable of use by all relevant application without duplication.” • The database approach is therefore centered on data, rather than on the process applied to the data 14 File oriented system vs dbms • A DBMS enables an organization to implement the database approach. It does this by supporting description of data, both in term of how it is physically stored and in term of the logical structure of the data • The physical structure of the data is to do with how the data is represented on storage device. The logical structure of the data is to do with how it appears to the user of the database 15 File oriented system vs dbms • DBMS makes possible a natural representation of data by shielding the user from the physical data structures. • The users sees only the data which is structured in a way that models the structure of the information it represents, and not the ways in which it is stored. 16 File oriented system vs dbms • The description of the data structures are called schemas. • The database has two parts: – Database intension which is the set of schemas which define the structure of database. – Database extension which is the data values themselves, contained in the database 17 SUMMARY • An organization can be viewed as a system of activities coordinated by a flow information. • The conventional file-oriented approach is to build computer systems to support activities, or applications. • The database approach is to treat the database as an entity in its own right, and to design it to model the organization. 18 SUMMARY • A special program called a database management system (DBMS) is used to manage and provide access to the database. • The database administrator (DBA) is responsible for managing the database 19