What is an attribute? How is it related to an entity? An attribute is a characteristic of an entity. Specific values of attributes—called data items. Entity: A generalized class of people, places, or things for which data is collected, stored, and maintained. 2. Define the term database. How is it different from a database management system? A database is an organized collection of data. Like other components of an information system, a database should help an organization achieve its goals. A database provides an essential foundation for an organization’s information and decision support system Database management system (DBMS) :Group of programs that manipulate the database and provide an interface between the database and the user of the database and other application programs.
3. What is the hierarchy of data in a database 3. What is the hierarchy of data in a database? hierarchy of data Bits, characters, fields, records, files, and databases. 4. What is a flat file? in databases a flat file refers to data files that contain records with no structured relationships. Flat files may contain only basic formatting, have a small fixed number of fields, and it may or may not have a file format.
5. What is the purpose primary key 5. What is the purpose primary key? How can it be useful in controlling data redundancy? A primary key is a field or set of fields that uniquely identifies the record. It can be useful in distinguishing records so that they can be accessed, organized, and manipulated. An employee key is another example that is the employee number is an example of a primary key. Locating a particular record that meets a specific set of criteria might be easier and faster using a combination of secondary keys. An example would be if several customers had the same last name then the clerk would be able to check other fields such as address, first name, and so on to find the correct customer record. 6. What Is the purpose of data cleanup? The process of looking for and fixing inconsistencies to ensure that data is accurate and complete.
7. What are the advantages of the database approach 7. What are the advantages of the database approach? Improves strategic use of data, ease of modification, and ease of access to data and information. 8. What is data modeling? What is its purpose? Briefly describe three commonly used data models. Diagramming data entities and their relationships. Three types are: Enterprise Data Models, Entity-Relationship Models, and Relational Database Models. The purpose is to give a visual model of the organization of data.
9. What is a database schema, and what is its purpose 9. What is a database schema, and what is its purpose? database schema is a set of formulas (sentences) called integrity constraints imposed on a database. A database schema is a way to logically group objects such as tables, views, stored procedures etc. Think of a schema as a container of objects. 10. How can a data dictionary be useful to database administrators and DBMS software engineers? A data dictionary is a detailed description of all the data used in the database. It is useful because administrators and engineers are able to see a detailed description of all of the data used in a particular database.
11. Identify important characteristics in selecting a database management system. Data integration,data independence,data sharing,data redundancy,data security,integrity and consistency,concurrency and recovry 12. What is the difference between a data definition language (DDL) and a data manipulation language (DML)? A DDL is a collection of instructions and commands used to define and describedata and relationships in a specific database.A DML is a specific language, provided with a DBMS, which allows users toaccess and modify the data, to make queries, and to generate reports.
13. What is the difference between projecting and joining 13. What is the difference between projecting and joining? Manipulating data to eliminate columns in a table. While joining is to manipulating data to combine two or more tables. 14. What is a distributed database system? Database in which the data may be spread across several smaller databases connected via telecommunications devices.
15. What is a data warehouse, and how is it different from a traditional database used to support OLTP? A data warehouse is a subject-oriented,Integrated, time varient and non-volatile collection of data in support of managements decision making process. The OLTP database records transactions in real time and aims to automate clerical data entry processess of a bussiness entity. A traditional DBMS might only store the monthly expenses. 16. What is meant by the “front end” and the “back end” of a DBMS? The front-end is also reffered to as the client-side and is sometimes considered “web design”. The back-end of the web industry is often called the server side. Often when someone says they are a “web developer” they are saying they work on the back-end of sites.
17. What is data mining. What is OLAP. How are they different 17. What is data mining? What is OLAP? How are they different? An information-analysis tool that involves the automated discovery of patterns and relationships in a data warehouse. Software that allows users to explore data from a number of perspectives. 18. What is an ORDBMS? What kind of data can it handle? A DBMS capable of manipulating audio, video, and graphical data. An object relational database is also called an object relational database management system (ORDBMS). This system simply puts an object oriented front end on a relational database (RDBMS).
19. What is business intelligence. How is it used 19. What is business intelligence? How is it used? Bussines intelligence is an ubrella term that referes to a variety of software applications used to analyze andorganizations raw data. BI use to improve decision making ,cutcosts and identifty new bussiness oppportunities.Cios use BI to identify inefiicient bussiness processess that are ripe for re-engineering. 20. In what circumstances might a database administrator consider using an object-oriented database?