Lect 21 components_of_database_management_system
- 1. Components of DatabaseComponents of Database Management SystemManagement System What is DBMS?What is DBMS? AA DBMS is computer software designed for the purpose ofDBMS is computer software designed for the purpose of managing databases based on a variety of data modelsmanaging databases based on a variety of data models Why use a DBMS?Why use a DBMS? Reduced application development time (Queries)Reduced application development time (Queries) Data independence and efficient accessData independence and efficient access Concurrent accessConcurrent access Crash recoveryCrash recovery
- 2. DBMS benefitsDBMS benefits Improved strategic use of corporate dataImproved strategic use of corporate data Reduced complexity of the organisationReduced complexity of the organisation``s information systemss information systems environmentenvironment Reduced data redundancy and inconsistencyReduced data redundancy and inconsistency Enhanced data integrityEnhanced data integrity Application-data independenceApplication-data independence Improved securityImproved security Reduced application development and maintenance costsReduced application development and maintenance costs Improved flexibility of information systemsImproved flexibility of information systems Increased access and availability of data and informationIncreased access and availability of data and information
- 3. DBMS-a software packageDBMS-a software package DBMS is a large software package that carries out diverseDBMS is a large software package that carries out diverse tasks including the provision of facilities to enable the user totasks including the provision of facilities to enable the user to access and modify information in the database.access and modify information in the database. It is an intermediate link physical database,the computer andIt is an intermediate link physical database,the computer and the operating system,and ,on the other hand the users.the operating system,and ,on the other hand the users.
- 4. Intermediaries of componentsIntermediaries of components data hardware software users
- 5. UsersUsers Three broad classes of users:Three broad classes of users: Application programmersApplication programmers -develop the application programmes.-develop the application programmes. -can manipulate the database in all possible ways.-can manipulate the database in all possible ways. End usersEnd users -access the database from a terminal using a query language-access the database from a terminal using a query language provided by the database system.provided by the database system. Database administrator:Database administrator: -who is responsible for the design, construction, and maintenance-who is responsible for the design, construction, and maintenance of a database.of a database.
- 6. SoftwareSoftware controls the organization, storage, management, and retrieval ofcontrols the organization, storage, management, and retrieval of data in a database.data in a database. It includes operating system, network software,and theIt includes operating system, network software,and the application programsapplication programs which encompasses the physical interconnections and deviceswhich encompasses the physical interconnections and devices required to store and execute (or run) the software.required to store and execute (or run) the software. software consists of a machine language specific to an individualsoftware consists of a machine language specific to an individual processor.processor. It is usually written in high-level programming language moreIt is usually written in high-level programming language more efficient for humans to use .efficient for humans to use .
- 7. HardwareHardware Hardware of a system can range from a PC to a networkHardware of a system can range from a PC to a network of computers.of computers. It also includes various storage devices like hard discsIt also includes various storage devices like hard discs and input and output devices like monitor, printer, etc.and input and output devices like monitor, printer, etc. DATADATA Data stored in a database includes numerical data suchData stored in a database includes numerical data such as whole numbers and floating point numbers and nonas whole numbers and floating point numbers and non numerical data such as characters, date, or logical data.numerical data such as characters, date, or logical data. More advanced systems may include more complicatedMore advanced systems may include more complicated data entities such as pictures and images as data types.data entities such as pictures and images as data types.
- 8. Components of DBMSComponents of DBMS User InterfaceUser Interface Data ManagerData Manager File ManagerFile Manager Disk ManagerDisk Manager Physical DatabasePhysical Database
- 9. User InterfaceUser Interface The user interface is the is the aggregate of means by which theThe user interface is the is the aggregate of means by which the people –the user interacts with the system a particular machine,people –the user interacts with the system a particular machine, device,computer programme or other complex tools.device,computer programme or other complex tools. The user interface provides the means of:The user interface provides the means of: -Input,allowing the users to manipulate the system.-Input,allowing the users to manipulate the system. -Output,allowing the system to produce the effects of-Output,allowing the system to produce the effects of the users manipulation.the users manipulation. It refers to the graphical, textual and auditory information theIt refers to the graphical, textual and auditory information the programme presents to the user and the control sequences the userprogramme presents to the user and the control sequences the user employs to the program.employs to the program.
- 10. Data ManagerData Manager itit is a program which allows you to process and manipulate your data in a easy and logical manneris a program which allows you to process and manipulate your data in a easy and logical manner using a graphical interface.using a graphical interface. DataManager reads and writes deliminated files such as comma seperated files (CSV) and also canDataManager reads and writes deliminated files such as comma seperated files (CSV) and also can read data from ODBC Data Sourcesread data from ODBC Data Sources.. It allows you to construct a conceptial design on how you are going to process your data andIt allows you to construct a conceptial design on how you are going to process your data and transform it into another form.transform it into another form. You form your design by adding functional nodes and linking them such that the links form the dataYou form your design by adding functional nodes and linking them such that the links form the data flow through nodes on a graphical work area.flow through nodes on a graphical work area. You form your design by adding functional nodes and linking them such that the links form the dataYou form your design by adding functional nodes and linking them such that the links form the data flow through nodes on a graphical work area.flow through nodes on a graphical work area. Each node performs a single function on your data, once it completes it passes your data to the nodeEach node performs a single function on your data, once it completes it passes your data to the node it is linked to and the process continues until the data encounters a output node.it is linked to and the process continues until the data encounters a output node. You can form a simple design or a complicated design with hundreds of nodes and multiple inputYou can form a simple design or a complicated design with hundreds of nodes and multiple input and output nodes.and output nodes.
- 11. File ManagerFile Manager A file manager or file browser is a computer program that provides aA file manager or file browser is a computer program that provides a user interface to work with file systems.user interface to work with file systems. They are very useful for speeding up interaction with filesThey are very useful for speeding up interaction with files The most common operations on files are create, open, edit, view,The most common operations on files are create, open, edit, view, print, play, rename, move, copy, delete, attributes, properties,print, play, rename, move, copy, delete, attributes, properties, search/find, and permissions.search/find, and permissions. File managers may contain features inspired by web browsers,File managers may contain features inspired by web browsers, including forward and back navigational buttonsincluding forward and back navigational buttons.. file managers also provide the ability to extend operations using userfile managers also provide the ability to extend operations using user written scripts.written scripts. It passes request to disk manager.It passes request to disk manager.
- 12. Disk ManagerDisk Manager Disk manager is a simple filesystem configurator that allows you to:Disk manager is a simple filesystem configurator that allows you to: -Automatically detect new partitions at startup.-Automatically detect new partitions at startup. -Fully manage configuration of filesystem-Fully manage configuration of filesystem.. Disk Manager logs every change you make to the filesystemDisk Manager logs every change you make to the filesystem configurationconfiguration explaining hardware conceptsexplaining hardware concepts documenting switches of many of the existing disksdocumenting switches of many of the existing disks putting into place custom software drivers, notably those related toputting into place custom software drivers, notably those related to maximum disk or partition sizemaximum disk or partition size providing testing and informational utilitiesproviding testing and informational utilities
- 13. Interaction of DBMSInteraction of DBMS componentscomponents DataData ManagerManager PhysicalPhysical DatabaseDatabase FileFile ManagerManager DBMS userDBMS user interfaceinterface DiskDisk ManagerManager Recovery Manager Transaction Manager
- 14. Explanation of interactionsExplanation of interactions The user requests for specific information with the help of userThe user requests for specific information with the help of user interface.interface. This request is processed by data manager and after processing ,dataThis request is processed by data manager and after processing ,data manager request for specific records to the file manager.manager request for specific records to the file manager. The file manager then request for the specific block to the diskThe file manager then request for the specific block to the disk manager.manager. The disk manager then then retrives the block and sends it to fileThe disk manager then then retrives the block and sends it to file manager,which sends the required record to data manager.manager,which sends the required record to data manager. The transaction manager supervises the data transactions that isThe transaction manager supervises the data transactions that is carried out between the data manager, file manager, and the diskcarried out between the data manager, file manager, and the disk manager.manager. The recovery manager keeps a check on the transacted data so thatThe recovery manager keeps a check on the transacted data so that in case of system failure, the data can be protected.in case of system failure, the data can be protected.