DATABASE APPLICATION DEVELOPMENT SAK 3408 Introduction (week 1)

SAK3408 by PSS (W1) What is a DATABASE ?  Definition: A collection of data stored in a standardized format, designed to be shared by multiple users.

SAK3408 by PSS (W1) What is DBMS ?  Definition Software that defines a database, stores the data, supports a query language, produces reports, and creates data entry screens.

SAK3408 by PSS (W1) Everyday example  Maybank2u, CIMBClick  Sistem JPN  Library, Amazon  Universities student records  ……………….. Discussion: Is Google a DBMS or not?

SAK3408 by PSS (W1) History of DBMS end70s E.F Codd proposed relational model Ingres and System R was developed Developed at UCB Led to Ingres Corp, Sybase, MS SQL server Used QUEL Developed at IBM Led to IBM SQL & DB2, HP Allbase Used SEQUEL The term : RDBMS was developed P. Chen proposed ER model (1976) Commercialization of relational system SQL The intergalactic standard The Internet usability Introducing web/Internet/DB connector ASP, Front Page, Java Servlets JDBC. Dream Weaver, Oracle Developer 2000, MySQL, Apache, Gcc, cgi etc. Solid growth of DB system with more interactive application Future Trends? Terabyte system appearing, needing clickstream analysis with focus on data mining, data warehousing, data marts…

SAK3408 by PSS (W1) The old file method  Uncontrolled Duplication Wastes space Hard to update all files  Inconsistent data  Inflexibility Hard to change data Hard to change programs  Limited data sharing  Poor enforcement of standards  Poor programmer productivity  Excessive program maintenance

SAK3408 by PSS (W1) Problem with file method  Files defined in program Cannot read file without definition Hard to find definition Every time you alter file, you must rewrite code Change in a program/file will crash other code Cannot tell which programs use each file

SAK3408 by PSS (W1) Problem with file method  Multiuser problems Concurrency Security  Access  Backup & Restore Efficiency  Indexes  Programmer talent System Application

SAK3408 by PSS (W1) Advantages of Database Approach  Minimal data redundancy.  Data consistency.  Integration of data.  Sharing of data.  Enforcement of standards.  Ease of application development.  Uniform security, privacy and integrity.  Data independence.

SAK3408 by PSS (W1) DesignSQLProgram Best: Spend your time on design and SQL. Design SQL Program Worst: Compensate for poor design and limited SQL with programming. Building a DBMS application

SAK3408 by PSS (W1) Environment of database system  Data is most important Data defined first Standard format  Access through DBMS Queries, Reports, Forms Application Programs 3GL Interface  Data independence Change data definition without changing code Alter code without changing data Move/split data without changing code All Data DBMS Program1Program2 Queries Reports

SAK3408 by PSS (W1) Components of DBMS All Data Database Engine Data Dictionary Security Query Processor Form Builder Report Writer 3GL Connector Program Application Generator

SAK3408 by PSS (W1) Database Model  Hierarchical  Network  Relational  Entity relational  Object-oriented

SAK3408 by PSS (W1) Hierarchical Database  Hierarchical model’s basic logical structure is best understood with manufacturing process.  Example : A Table Customer Order Items Ordered

SAK3408 by PSS (W1) Network Database  Similar to hierarchical database model, but allows a record to have more than one parent.  A relationship is called a set.  Each set have two record Owner member SALESREPCOSTUMER Invoice Inventory Product Payment

SAK3408 by PSS (W1) Relational Database  Adding advantage by a host of other function that make easier to understand and implement.  Is perceived by the user as a collection of table.  Table are related to each other by sharing the common entity. Pelajar Kursus daftar

SAK3408 by PSS (W1) Entity relational Database  Graphical representation of relational model  Is illustration of entities and their representation in database structure.

SAK3408 by PSS (W1) Object-Oriented DBMS Customer CustomerID Name … Add Customer Drop Customer Change Address Order OrderID CustomerID … NewOrder DeleteOrder … OrderItem OrderID ItemID … OrderItem DropOrderItem … Item ItemID Description … New Item Sell Item Buy Item … Government Customer ContactName ContactPhone Discount, … NewContact Commercial Customer ContactName ContactPhone … NewContact

SAK3408 by PSS (W1) Examples of Commercial Systems  Oracle  Ingres  Informix (Unix)  DB2, SQL/DS (IBM)  Access (Microsoft)  SQL Server (Microsoft +)  Many older (Focus, IMS,...)  Many limited PC (dBASE, Paradox, …)

SAK3408 by PSS (W1) Class Discussion  Multimedia Database ?

SAK3408 by PSS (W1) Recalled : Teaching Plan W1  Database Definition, Database Management System (DBMS)  Advantages of Database Management  Environment of Database System  Components of Database Management System  Brief History of Database Management System