Chapter 1 - Database Management Systems
What is a primary key?
A minimal collection of columns (attributes) in a table on which all columns are functionally dependent and that is chosen as the main direct-access vehicle to individual rows
What is an entity?
A person, place, object, event, or idea for which you want to store
What is a Database Management system (DBMS)
A program, or collection of programs, through which users interact with a database. Access, Oracle, DB2, MySQL, and SQL Server are examples of it
What is Integrity constraint?
A rule that must be followed by data in a database
What are Forms?
A screen objects used to maintain, view, and print data from a database
What is Entity-relationship (E-R) diagram?
A visual way to represent a database. Rectangles represent entities, and lines represent relationships between connected entities
What is an column or a field?
Another name for attribute
What are Reports?
DBMS asks questions about the desired content and appearance of each report then creates it automatically based on the answers
What are the problems associated with redundancy?
Difficulty accessing related data, limited security, size limitations, changes are cumbersome and time consuming, waste spaces, and leads to inconsistencies
What is a Database Administration?
The individual or group that is responsible for a database
What is a Database Administrator?
The individual who is responsible for a database, or the head of database administration.
What is an attribute?
A characteristic or property of an entity
What is a record?
A collection of related fields; can be thought of as a row in a table
What is Integrity?
A database has integrity if the data in it satis- fies all established integrity constraints
What is redundancy?
The duplication of data or the storing of the same data in more than one place
What is a one-to-many relationship?
The first entiy is associated with all of the occurances of the second entity, but the second entity is associated with only one of the occurance of the first entity
What is Security?
The prevention of unauthorized access to a database
What is a Database Design?
The process of determining the content and structure of data in a database in order to support some activity on behalf of a user or group of users
What is Data Independence?
The property that lets you change the structure of a database without requiring you to change the programs that access the database; examples of these programs are the forms you use to interact with the database and the reports that provide information from the database.
What is a data file?
a file that are used to store data and the computer counterpart to an ordinary paper file. Spreadsheets, word-processors documents, and web pages are examples of it
What is a database?
a structure that can store information about multiple types of entities, the attributes of those entities, and the relationships between the entities
What is a relationship?
an association between entities
