Presentation on theme: "Lecture-7/ T. Nouf Almujally"— Presentation transcript:
1Lecture-7/ T. Nouf Almujally Data Resource ManagementSection 1: “Technical Foundations of Database Management”Chapter 5Lecture-7/ T. Nouf Almujally1
2Outline Section 1: Technical Foundations of Database Management Fundamental Data ConceptsDatabase StructuresDatabase DevelopmentData planning and Database Design (not required)
3Section 1Technical Foundations of Database Management
4Database ManagementData are a vital organizational resource that need to be managed like other important business assets.Today's business enterprise cannot succeed without quality data about their internal operations and external environment.In all information systems, data resources must be organized and structured in some logical manner so that they can be accessed easily, processed efficiently, retrieved quickly, and managed effectively.Database provide a logical organization method and easy access to the data stored in it.
5Logical Data Elements Data may be logically organized into: character fieldrecordfiledatabase
6Logical Data Elements Character Field (data item) Record Database File (table, flat file)DatabaseA single alphabetic, numeric, or other symbolConsists of a grouping of related characters.Represents an attribute (characteristic) of some entity (object, person, place, event)Examples… salary, job titleGrouping of all the fields used to describe the attributes of an entityExample… payroll records with name, SSN, pay ratePrimary Key.Group of related recordsIntegrated collection of logically related data elementsIt consolidates records previously stored in separate files into a common pool of data elements that provides data for many applications
8Fundamental Data Concepts The data stored in a database are independent of the application programs using them and of the type of storage devices on which they are stored.Databases contain data elements describing entities and relationships among entities.
9Electric Utility Database Business applications that access the data in the DB
10Database StructuresThe relationships among the many individual data elements stored in databases are based on one of several logical data structures, or models.Database management system (DBMS) packages are designed to use a specific data structure to provide end users with quick, easy access to information stored in databases.Five fundamental database structures:Hierarchical , network , relational, object-oriented and multidimensional models.
11Common Database Structures: Hierarchical Root ElementEarly mainframe DBMS packages used this structure.Records arranged in a hierarchy or tree-like structureRelationships are one-to-many
12Common Database Structures: Network Can represent more complex logical relationships and is still used by mainframe DBMS packages.Many-to-many relationships among records.
13Common Database Structures: Relational Most widely used structureUsed by microcomputer DBMS packages, as well as by most midrange and mainframe systems.Data elements are stored in tables (sometimes referred to as relations).Row represents a record; column is a field.DBMS packages based on relational model can relate data in one table with data in another, if both tables share a common data element.Relational operations include:Select… Create a subset of records that meet a stated criterion. Example: employees earning more than $30,000Join… Combine two or more tables temporarily. Looks like one big table.Project… Create a subset of columns in a table
14Common Database Structures: Relational A lot of commercial products exist to create and manage relational models:Mainframe relational DB applications:Oracle10g from OracleDB2 from IBMMidrange DB applications:SQL Server from Microsoft.The most commonly used DB application for the PC is Microsoft Access.
15Common Database Structures: Multidimensional Variation of relational model that uses multidimensional structures to organize data and express the relationships between them.Data elements are viewed as being in cubes. Each side of the cube is considered a dimension of the data.Each dimension represent a different category.Have become the most popular database structure for the analytical databases that support Online Analytical Processing (OLAP) applications, in which fast answers to complex business quires are expected.
19Common Database Structures: Object-Oriented the object-oriented model is considered one of the key technologies of a new generation of multimedia Web-based applications.An object consists ofData values describing the attributes of an entityOperations that can be performed on the dataEncapsulation Combine data and operationsInheritance New objects can be created by replicating some or all of the characteristics of parent objectsOODBMS now is popular in CAD and in multimedia Web-based applications.Supports complex data types more efficiently than relational databasesExamples: graphic images, video clips, web pages
20Common Database Structures: Object-Oriented major relational DBMS vendors add object-oriented modules to their relational software.Examples include multimedia object extensions to IBM’s DB2 and Oracle’s object- based “cartridges” for Oracle.
21Evaluation of Database Structures Hierarchical- Was for DB’s used for the structured, routine types of transaction processing of many business in the early years of data processing and computing.- Can’t handle many-to-many relationshipNetwork- More flexible than hierarchical- Unable to handle ad hoc requestsRelational- Easily responds to ad hoc requests- Easier to work with & maintainCan't process large amounts of bus. Transactions as efficient or quick as hierarchical or networkcan’t process complex applications as object-oriented models.- Ex: Oracle, DB2, Access , Lotus Approach
22Con. Object-Oriented Multidimensional Can process complex, high volume applications.- The use of this model is growing steadily.- Play a great role in web-based applications.MultidimensionalThe use of this model is growing steadily.- Play a great role in OLAP applications.
23Database DevelopmentDatabase management package like Microsoft Access or Lotus Approach allow end users to develop the databases they need easily.Large organizations usually place control of enterprise database development in the hands of (DBA) and other database specialists.
24Database Development Database Administrator (DBA) In charge of enterprise-wide database developmentImproves integrity and security of organizational databasesUses Data Definition Language (DDL) in DBMS to develop and specify data content, relationships, and structureThis information is then stored in a database of data definitions andspecifications called a data dictionary or metadata repositorywhich is managed by the DBA
25Data Dictionary Data Dictionary Contains information on… Directory holds information about the database and the data that it stores (data about data = metadata)Relies on specialized software component to manage a database of data definitionsNames and descriptions of all types of data records and their interrelationshipsRequirements for end users’ access and use of applicationsContains information on…Database maintenanceSecurity
27Database DevelopmentDeveloping a large DB of complex data types can be a complicated task.Database administrator and the database design analyst work with end users and system analysts to model the business processes and the data they require. Then they determine:What data definitions should be included in the DB.What relationships should exist among the data elements.