Ch 7

Question 1

Authentication

Answer 1

Authentication is the process the DBMS uses to verify that only registered users access the database.

Question 2

Schema

Answer 2

In the SQL environment, a schema is a logical group of database objects, such as tables and indexes - that are related to each other. Usually, the schema belongs to a single user or application. A single database can hold multiple schemas that belong to different users or applications.

Question 3

Wildcard character

Answer 3

A wildcard character is a symbol that can be used as a general substitute for other characters or commands. For example, to list all attributes and all rows of the PRODUCT table, use the following:

SELECT * FROM PRODUCT;

Question 4

Subquery

Answer 4

A subquery, also known as a nested query or an inner query, is a query that is embedded (or nested) inside another query. The inner query is always executed first by the RDBMS.

Question 5

Alias

Answer 5

An alias is an alternate name given to a column or table in any SQL statement.

Question 6

Cascading order sequence

Answer 6

Used when you want to order a list by multiple values. It can be easily created by listing several attributes, separated by commas, after the ORDER BY clause:

ORDER BY EMP_LNAME, EMP_FNAME, EMP_INITIAL