Thursday, December 5, 2019
Design of Database Assignment
Questions: 1. Describe how the design of a database can affect data quality, integrity, and security. 2. Discuss the role of a data dictionary in ensuring both the quality of enterprise-wide data and data within a specific database application. 3. Explain the concept of data warehousing and its application to decision support. Answers: 1) The design of database can affect the data quality, integrity, and security in following ways-: 1) Data Quality As we all know that in any organization there are various objects that seems to be important from the designing point of view. However, the database designer studies the system properly and after that generates the overall design of the system. And the type of data he use to design the database affect the quality of database. And if the quality of data is used in the database design it helps in providing reliability to the data that helps the organization in decision making. 2) Integrity As in the good database design the designer use the concept of referential integrity which means referencing the data in terms of primary key and foreign key. And if this concept is used in designing it ultimately affect the data integrity of the system. suppose if there is some changes required in the same data used at various places in the database. Then with the help of integrity concepts the value of data get changed at every place. 3) Security If the database designer use the concept of permission in the database in order to provide permission for accessing the confidential data of the organization. So in this way design of the database affect the security of the system by providing permissions to particular user who have authority to access the data. 2) Role of a data dictionary in ensuring both the quality of enterprise-wide data and data within a specific database application are as follows. 1) Data dictionary is a term which is used for explaining the data about data, or in simple words we can say that metadata. Data dictionary explain the organizational data or each entity in the database which shows the quality of data the organization have. 2) As Data dictionary explains the each term in the database very clearly so it also helps any new database administrator to understand the database system fastly and also represent the organization the quality of data it have within the particular database application. 3) As the data dictionary expand the entity with its part. Then after viewing those part one can easily estimate the quality of data the database system of the organization have. And how effectively the database system helps in decision making. 3. Data warehousing Concept Data warehousing is a technique used to store the current and historical data of the organization in particular system of the organization. Data warehousing helps the organization in order to make comparison between the data of two different session. Data warehousing keeps all the details of the database. And after accessing the ware house it helps in presenting the details infront of organization in the forms of reports. And it also helps in making decision. The two main application of data warehousing towards decision support system are as-: 1) Data mining 2) Web mining References McHugh, J., Abiteboul, S., Goldman, R., Quass, D., Widom, J. (1997). Lore: A database management system for semistructured data. SIgMOD Record, 26(3), 54-66. Selinger, P. G., Astrahan, M. M., Chamberlin, D. D., Lorie, R. A., Price, T. G. (1979, May). Access path selection in a relational database management system. In Proceedings of the 1979 ACM SIGMOD international conference on Management of data (pp. 23-34). ACM. Stonebraker, M., Kemnitz, G. (1991). The POSTGRES next generation database management system. Communications of the ACM, 34(10), 78-92. Wakayama, S., Shimoi, T., Kobayashi, S., Munechika, H. (1999). U.S. Patent No. 5,920,869. Washington, DC: U.S. Patent and Trademark Office.