SESSION 7 MANAGING DATA DATARESOURCES

File Organization Terms and Concepts Field: Group of words or a complete number Record: Group of related fields File: Group of records of same type Database: Group of related files ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT

Data Hierarchy in a Computer System Figure 7-1 File Organization Terms and Concepts ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT

Entity: Person, place, thing, event about which information is maintained Attribute: Description of a particular entity Key field: Identifier field used to retrieve, update, sort a record File Organization Terms and Concepts ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT

Figure 7-2 Entitities and Attributes File Organization Terms and Concepts ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT

Data redundancy Program-Data dependence Lack of flexibility Poor security Lack of data-sharing and availability Problems with the Traditional File Environment ORGANIZING DATA IN A TRADITIONAL FILE ENVIRONMENT

THE DATABASE APPROACH TO DATA MANAGEMENT Creates and maintains databasesCreates and maintains databases Eliminates requirement for data definition statementsEliminates requirement for data definition statements Acts as interface between application programs and physical data filesActs as interface between application programs and physical data files Separates logical and design views of dataSeparates logical and design views of data Database Management System (DBMS)

Relational DBMS Represents data as two-dimensional tables called relationsRepresents data as two-dimensional tables called relations Relates data across tables based on common data elementRelates data across tables based on common data element Examples: DB2, Oracle, MS SQL ServerExamples: DB2, Oracle, MS SQL Server TYPES OF DATABASES THE DATABASE APPROACH TO DATA MANAGEMENT

Three Basic Operations in a Relational Database Select: Creates subset of rows that meet specific criteriaSelect: Creates subset of rows that meet specific criteria Join: Combines relational tables to provide users with informationJoin: Combines relational tables to provide users with information Project: Enables users to create new tables containing only relevant informationProject: Enables users to create new tables containing only relevant information THE DATABASE APPROACH TO DATA MANAGEMENT

Figure 7-7 Three Basic Operations in a Relational Database THE DATABASE APPROACH TO DATA MANAGEMENT

Hierarchical and Network DBMS Hierarchical DBMS Organizes data in a tree-like structureOrganizes data in a tree-like structure Supports one-to-many parent-child relationshipsSupports one-to-many parent-child relationships Prevalent in large legacy systemsPrevalent in large legacy systems THE DATABASE APPROACH TO DATA MANAGEMENT

Hierarchical DBMS Figure 7-8 THE DATABASE APPROACH TO DATA MANAGEMENT

Hierarchical and Network DBMS Network DBMS Depicts data logically as many-to-many relationshipsDepicts data logically as many-to-many relationships THE DATABASE APPROACH TO DATA MANAGEMENT

Figure 7-9 Network DBMS THE DATABASE APPROACH TO DATA MANAGEMENT

DisadvantagesOutdated Less flexible compared to RDBMS Lack support for ad-hoc and English language-like queries Hierarchical and Network DBMS THE DATABASE APPROACH TO DATA MANAGEMENT

Object-oriented DBMS: Stores data and procedures as objects that can be retrieved and shared automatically Object-relational DBMS: Provides capabilities of both object-oriented and relational DBMS Object-Oriented databases THE DATABASE APPROACH TO DATA MANAGEMENT

Conceptual design: Abstract model of database from a business perspective Physical design: shows how the database is actually arranged on direct access storage devices. CREATING A DATABASE ENVIRONMENT Designing Databases THE DATABASE APPROACH TO DATA MANAGEMENT

Distributing databases Stored in more than one physical location Partitioned database Duplicated database CREATING A DATABASE ENVIRONMENT THE DATABASE APPROACH TO DATA MANAGEMENT

Multidimensional Data Analysis On-line analytical processing (OLAP) Multidimensional data analysis Supports manipulation and analysis of large volumes of data from multiple dimensions/perspectives DATABASE TRENDS

Data warehouse Supports reporting and query tools Stores current and historical data Consolidates data for management analysis and decision making DATABASE TRENDS

Improved and easy accessibility to information Ability to model and remodel the data Benefits of Data Warehouses DATABASE TRENDS

Data mart Subset of data warehouse Contains summarized or highly focused portion of data for a specified function or group of users DATABASE TRENDS

Datamining Tools for analyzing large pools of data Find hidden patterns and infer rules to predict trends DATABASE TRENDS

Database server Computer in a client/server environment runs a DBMS to process SQL statements and perform database management tasks Application server Software handling all application operations Databases and the Web DATABASE TRENDS

Linking Internal Databases to the Web Figure 7-18 DATABASE TRENDS