ICS (072)Database Systems: A Review1 Database Systems: A Review Dr. Muhammad Shafique

ICS (072)Database Systems: A Review2 Outline A historical perspective Fundamentals Classifications Development process Administration

ICS (072)Database Systems: A Review3 History of DBMS Hardware 1970s Mainframes & Minicomputers 1980s Personal Computers & Workstations (desktop machines) Mid 1980s LAN to share resources 1990s LAN + PCs client-server computing LAN + WANdistributed computing

ICS (072)Database Systems: A Review4 History of DBMS Software 1970s Hierarchical & Network Data Models 1980s Relational Model Mainframe Relational DBMSs (DB2, Oracle,...) Late 1980s Database Servers (Oracle, Sybase, SQL Server) 1990s Database Serves + Front-end tools (client-server databases) Distributed & Replicated Databases Databases and World Wide Web Data Warehouses 2000s Data Streams

ICS (072)Database Systems: A Review5 Fundamentals Database concepts Database A database represents some aspect of the real world A database is a logically coherent collection of data with some inherent meaning. A database is designed, built, and populated with data for a specific purpose. It has an intended group of users and some preconceived applications in which these users are interested. Database Management System A database management system (DBMS) is a collection of programs that enables users to create and maintain a database.

ICS (072)Database Systems: A Review6 Fundamentals (Cont.) Database concepts Data model A collection of concepts that can be used to describe the structure of a database Schema The description of a database is called the database schema, which is specified during database design and is expected not to change frequently The three-schema architecture Internal schema Conceptual schema External schema

ICS (072)Database Systems: A Review7 Fundamentals (Cont.) Database concepts Data independence: logical and physical Database languages DBMS languages Database interfaces Data modeling Conceptual Logical Physical Database design Normalization

ICS (072)Database Systems: A Review8 Fundamentals (Cont.) Database issues Query processing and optimization Transaction processing and concurrency control Database backup and recovery Security Performance monitoring and reorganization

ICS (072)Database Systems: A Review9 Classifications Logical organization of data Records-based database systems Object-oriented database systems Object-relational database systems Deductive/logic database systems Functional database systems Physical organization of data Centralized database systems Distributed database systems Homogeneous and heterogeneous Client-server database systems Mobile database systems

ICS (072)Database Systems: A Review10 Classifications (Cont.) Contents Symbolic databases Textual databases Multi-media databases Image databases Spatial databases Temporal databases Application domain Engineering databases Scientific databases Statistical databases Manufacturing databases Business

ICS (072)Database Systems: A Review11 Classifications (Cont.) Data usage Operational databases Decision-support databases Data warehousing Data mining Tactical and planning databases Nature of data Structured databases Semi-structured (like XML data) Unstructured (like Web)

ICS (072)Database Systems: A Review12 Classifications (Cont.) Self modifiability Passive databases Active databases Triggers

ICS (072)Database Systems: A Review13 Historical Development of Database Technology Early Database Applications The Hierarchical and Network Models were introduced in mid 1960’s and dominated during the seventies. A bulk of the worldwide database processing still occurs using these models. Relational Model based Systems The model that was originally introduced in 1970 was heavily researched and experimented with in IBM and the universities. Relational DBMS Products emerged in the 1980’s.

ICS (072)Database Systems: A Review14 Historical Development of Database Technology Object-oriented applications OODBMSs were introduced in late 1980’s and early 1990’s to cater to the need of complex data processing in CAD and other applications. Data on the Web and E-commerce Applications Web contains data in HTML (Hypertext markup language) with links among pages. This has given rise to a new set of applications and E-commerce is using new standards like XML (eXtended Markup Language).

ICS (072)Database Systems: A Review15 Database Development Organizational context for using database systems Early1970s to mid-1980s: large centralized repositories of data managed by single centralized DBMS Mid-1980s to late 1990s: personal databases, client-server databases, data dictionary systems, data warehousing, and data mining Current trend: distributed client-server database systems with Web applications Data administration Strategic planning, Setting policies and standards, DBMS independent Database administration Control and supervision, Enforce policies and standards, DBMS specific

ICS (072)Database Systems: A Review16 Database Development (Cont.) Information system life cycle Feasibility analysis Requirements collection and analysis, Design (database design and application design), Implementation, Validation and acceptance testing, Deployment, operation and maintenance

ICS (072)Database Systems: A Review17 Database Development (Cont.) Database application system life cycle System definition ---scope of the database, its users, and its applications are defined Database design Database implementation Loading or data conversion Application conversion Testing and validation Operation Monitoring and maintenance

ICS (072)Database Systems: A Review18 Database Design

ICS (072)Database Systems: A Review19 Database Design (Cont.) Requirements collection and analysis User groups, application areas, existing documentation, current operating environment Conceptual database design Conceptual schema design Centralized approach View integration approach Transaction design Choice of DBMS Logical design (Data model mapping) Physical design System implementation

ICS (072)Database Systems: A Review20 Administration Database Administration Functions Data as an organizational asset Data-information-decision cycle Database planning, including the definition of standards, procedures, and enforcements Database Development Database operations, performance monitoring and tuning Database training and support DBA must define, communicate, and enforce procedures for Database security, privacy, and integrity Database backup and recovery

ICS (072)Database Systems: A Review21 Summary Fundamentals of database systems Classifications of database systems Development process of database systems Database administration