Data Definition Language

Describe the ways in which database technologies could be used by an office stationery supply company to achieve low-cost leadership. Answer: Sales databases could be used to make the supply chain more efficient and minimize warehousing and transportation costs.

 

You can also use sales databases, as well as text mining and sentiment analysis, to determine what supplies are in demand by which customers and whether needs are different in different geographical areas. Business intelligence databases could be used to predict future trends in office supply needs, to help anticipate demand, and to determine the most efficient methods of transportation and delivery.

Identify and describe three basic operations used to extract useful sets of data from a relational database. Answer: The select operation creates a subset consisting of all records (rows) in the table that meets stated criteria.

The join operation combines relational tables to provide the user with more information than is available in individual tables. The project operation creates a subset consisting of columns in a table, permitting the user to create new tables that contain only the information required.

List and describe three main capabilities or tools of a DBMS. Answer: A data definition capability to specify the structure of the content of the database. This capability would be used to create database tables and to define the characteristics of the fields in each table.

A data dictionary to store definitions of data elements in the database and their characteristics. In large corporate databases, the data dictionary may capture additional information, such as usage; ownership; authorization; security; and the individuals, business functions, programs, and reports that use each data element.

A data manipulation language, such as SQL, that is used to add, change, delete, and retrieve the data in the database. This language contains commands that permit end users and programming specialists to extract data from the database to satisfy information requests and develop applications.