Exam 2: The Relational : Introduction, QBE, and Relational Algebra

QBE is a visual approach to writing queries.​

The attributes of an entity become the fields or columns in a table.​

Multiple entries in tables are often called ____________________.​

Explain what relational algebra is and how it is used.​

When duplicate column names exist in a database and you need to indicate the column to which you are referring,____.​

A relational database handles entities,attributes,and relationships by storing each entity in its own table.​

Two tables are considered to be ____ compatible if they have the same number of columns and their corresponding columns represent the same type of data.​

Rows are also called ____.​

A ____ query creates a new table using the query results.​

​Based on the statement below,which of the following is the primary key? Rep (RepNum,LastName,FirstName,Street,City,State,PostalCode Commission,Rate)

Which operation will allow you to extract data from more than one table?​

Discuss the difference between the major sort key and the minor sort key.​

The concept of grouping means that statistics will be calculated for individual records.​

The ____ command within relational algebra takes a vertical subset of a table.​

In an AND criterion,the overall criterion is true if either of the individual criteria is true.​

In a relation,the order of the columns is important.

You can restrict the output from a join to include only certain columns by using the ____ command.​

Using the product operator,if table A has 4 rows and table B has 4 rows,the number of rows in the product of these two tables is ____.​

A relational database is a collection of relations.

Each column in a table should have a unique name,and entries in each column should all "match" this column name.​