Database Management System Coursework - 1100 Words

Database Management System (Coursework Sample) Content: Database Management Systems:An Evaluation of the Property-4-R-Us real estate agencyà ¢Ã¢â€š ¬s caseOmari SimbaUnit/Subject Name and CodeInstructorà ¢Ã¢â€š ¬s NameInstitutionà ¢Ã¢â€š ¬s NameDepartment NameDateTable of Contents TOC \o "1-3" \h \z \u Introduction PAGEREF _Toc385800798 \h 3Different DBMS approaches and the actual DBMS employing them PAGEREF _Toc385800799 \h 3File System Approach to data storage PAGEREF _Toc385800800 \h 4Relational Database Management Systems (RDBMS) PAGEREF _Toc385800801 \h 4Object-Oriented Database Management System Approach PAGEREF _Toc385800802 \h 5Object-Relational Database Management System (ORDMS) approach PAGEREF _Toc385800803 \h 5Other Database Management Systems PAGEREF _Toc385800804 \h 6Conclusion PAGEREF _Toc385800805 \h 6Entity relationship diagram (ERD), identifying entities in the problem domain and showing relationships among entities7Identifying entities and their attributes7Entity Agent7Entity Client8Entity Property9Re lationship Among Entities9Deriving Entity Relationships9Entity Relationships10Entity Relationship Diagram11Relational Model of ERD12 Creating and populating tables property, entity and agentà ¢Ã¢â€š ¬Ãƒ ¢Ã¢â€š ¬Ãƒ ¢Ã¢â€š ¬Ãƒ ¢Ã¢â€š ¬Ãƒ ¢Ã¢â€š ¬Ãƒ ¢Ã¢â€š ¬Ãƒ ¢Ã¢â€š ¬Ãƒ ¢Ã¢â€š ¬Ãƒ ¢Ã¢â€š ¬Ãƒ ¢Ã¢â€š ¬Ãƒ ¢Ã¢â€š ¬Ãƒ ¢Ã¢â€š ¬..13References17IntroductionMany organizations are rapidly embracing management information systems as opposed to the traditional off-the-shelf filing, prompting an urgent rise for the need of data warehousing. The data fed into the management information systems and the information produced as the processed data need to be stored for future retrieval, aid in further data processing and act as future reference. Data can be stored in various forms in the computer. However, the file system and the database system approaches are the main forms of data storage mechanisms. The efficient mechanism for data storage among the two is the database system. A database is a co llection of real-world related data, collected and maintained to represent a given organisationà ¢Ã¢â€š ¬s information needs (Kumar, N.d, p. 2). The users can interact with the database by creating and maintaining its data through the database management system which is simply a set of programs that provides abstraction between the database and the user (Robbins, 1995, p. 3). Different database management systems (DBMS) are in existence, employing the Relational database approach, Object-oriented database approach, object-relational approach or the file system approach.Different DBMS approaches and the actual DBMS employing themEvery actual database management system implementation has a theory of operation behind it. The theory models and simulates the way data is stored and manipulated through update, search, insertion, deletion and retrieval. The theory lays down the framework for the operation of the entire database management system. It is important therefore to explore the v arious theories that have been advanced to simulate the working of the various database management systems.In any one specific approach, the following requirements must be met to qualify that given database management system as effective: efficiency should be met in manipulation of very large data, fault-tolerance and resilience in case of hardware or software failure without inconsistence and loss of data, capability to incorporate access control mechanisms to allow only authorized personnel to access it, have a long perseverance ability transcending time and nature of programs accessing its contents (Sirpal, N.d, P.4). * File System Approach to data storageThe file system is part of the operating system that manages the storage, manipulation and retrieval of files. The files are records of interrelated data/information. However, the file system has been found to have the following main flaw: data redundancy. * Relational Database Management Systems (RDBMS)In relational database ma nagement systems, the stored data is modelled into relations that exist between attributes of entities, which are real world objects. The attributes of that given entity is represented in the columns while the instance of the entity representing the real world object is represented by the records; rows of the table. According to Bergholt et al (1998), a relational database management system is a system that organizes data/information into two-dimensional relations as represented in the rows and columns of the database table (p.11). The record, also known as a tuple, contains information about a given instance of an entity with the component of each cell being of a primitive data type; integer (int), character (char), float, strings. (Subau, 2007, p.2). The RDBMS is advantageous in that it provides an easier approach in the analysis, design, implementation, testing, maintenance and use of the database, excellent conceptual simplification, excellent SQL querying ability which in comb ination produces an efficient database management system (Sirpal, N.d, p.30). It however has the following advantages: lack of enough space to handle the storage of media files like audio and visual files, the restriction of data being stored in rows and columns and poor design possibility (Sirpal. N.d, P. 30). * Object-Oriented Database Management System ApproachAccording to Bergholt et al (1998) the entity in the RDMS is modelled to be an object in the OODBMS, having the attributes of procedures, a group of values or simple values and pointers/references to other objects (p. 15). Data is stored along with those procedures that can act on that data (Subau, 2007, p.3). Structural properties and Behavioural properties of an object are defined by a finite set of attributes and finite set of methods that are uniquely inherent in any particular object ( Wang, N.d, p. 6). The OODBMS was designed to handle complex and large data while ensuring consistent, secure, extensible and controlle d data management, controlled and extensible data management, data independent mechanisms that would allow the implementation of the object-oriented model of database design (Sirpal, N.d, p. 31). The theory also inherits other powerful object-oriented language capabilities like data encapsulation, inheritance, polymorphism and use of objects to represent real world entities, making it better than RDBMS (Sirpal, N.d, p.31). * Object-Relational Database Management System (ORDMS) approachThe object-relational approach is an attempt to extend the functionalities of relational database managements (RDBMS) systems with the object-oriented approach of database design by attempting to bridge the gap between the two (Wang, N.d, p. 4). Both features from the two approaches must be combines to produce a real ORDBMS (Bergholt et al., 1998). * Other Database Management SystemsApart from the three main database design approaches discussed above, other minor database design theories have been ad vanced. GÃÆ' ¼ting (1994) proposes a spatial database model system that supports spatial data types and querying languages to achieve spatial join methods and indexing suitable for geographic information system applications (p. 1). Parallel and distributed database management systems have also been proposed. Parallelism achieved through partition and pipelining techniques have proven to achieve database access efficiency through indexing, querying and data loading experimental techniques (Ramakrishnan et al. 1992). Combining parallelism in a distributed environment can highly increase the efficiency of access to any distributed DBMS.ConclusionObject-Relational approach to database management system design proves to be the most efficient design mechanism for the database management system in our case. To improve it further, aspects of spatial, parallelism and distributed computing environments can be added to the database management system to make it more efficient to handle vir tually any data, from any geographical area in an efficient manner. A spatial distributed parallel ORDMS can be proposed to be deployed in managing the data warehousing needs of Property-4-R-Us real estate agency. 1 Entity relationship diagram (ERD), identifying entities in the problem domain and showing relationships among entities * Identifying entities and their attributes * Entity Agentagent_idCommission_rateW_phoneM_phonel-namesurnamef-nameCommission_codeAgent_contactsAgentAgent_nametotal_monthly_salesbase_salarypayment_datecheque_numberClient_id * Entity ClientClient-idFirst_nameproperty_idclient_phonemobile-phonelast_namesurnameClientClient-typeaddress * Entity PropertyProperty_idlocationAgreed_pricelistingForSale_dateYear_buildsizeAsking_priceHouse_designPropertyBuyer_idbuterDeposit_paidSettlement_dateroom_numbers * Relationship Among Entities * Deriving Entity Relationships Agent Property Client Agent Values Pays/Receives-payment Property valued Sold/bought Client Books a ppointment Buys/sells * Entity RelationshipsAgentValuesPropertyClientAgentPropertyAgentValuedPays or PaidBook AppointClientAgentClientBuys/SellsBought/soldPropertyClientProperty 2 * Entity Relationship DiagramA_nameagent_idchequeNoclient_idNo.RmsYr_buildH_designListDatetotalMonthsalesBaseSalarySettlementDatedescriptionAgreePricephoneClient_idPro_idAddressmobilef_namesurnamel_nameC_typeAddressrateMobilepayDatePro_idDepositAskPricesizelocationPaid/pays/Book AppointmentClientBuys/sells/bought/soldPropertyValued/ValuesAgent * Relational Model of ERDProperty Property_id (PK) Size Location ...