Quiz Discussion

For each attribute of a relation, there is a set of permitted values, called the ________ of that attribute.

• 1]

  Domain

• 2]

  Relation

• 3]

  Set

• 4]

  Schema

The _______ operator takes the results of two queries and returns only rows that appear in both result sets.

• 1]

  Union

• 2]

  Intersect

• 3]

  Difference

• 4]

  Projection

SELECT instructor.*
FROM instructor, teaches
WHERE instructor.ID= teaches.ID;

This query does which of the following operation?

• 1]

  All attributes of instructor and teaches are selected

• 2]

  All attributes of instructor are selected on the given condition

• 3]

  All attributes of teaches are selected on given condition

• 4]

  Only the some attributes from instructed and teaches are selected

A ________ is a pictorial depiction of the schema of a database that shows the relations in the database, their attributes, and primary keys and foreign keys.

• 1]

  Schema diagram

• 2]

  Relational algebra

• 3]

  Database diagram

• 4]

  Schema flow

The ______ clause allows us to select only those rows in the result relation of the ____ clause that satisfy a specified predicate.

• 1]

  Where, from

• 2]

  From, select

• 3]

  Select, from

• 4]

  From, where

A ________ in a table represents a relationship among a set of values.

• 1]

  Column

• 2]

  Key

• 3]

  Row

• 4]

  Entry

The most commonly used operation in relational algebra for projecting a set of tuple from a relation is

• 1]

  Join

• 2]

  Projection

• 3]

  Select

• 4]

  Union

SELECT name ____ instructor name, course id
FROM instructor, teaches
WHERE instructor.ID= teaches.ID;

Which keyword must be used here to rename the field name?

• 1]

  From

• 2]

  Rename

• 3]

  As

• 4]

  Join

The term attribute refers to a ___________ of a table.

• 1]

  Record

• 2]

  Column

• 3]

  Tuple

• 4]

  Key

SELECT *
FROM instructor
ORDER BY salary ____, name ___;

To display the salary from greater to smaller and name in ascending order which of the following options should be used?

• 1]

  Ascending, Descending

• 2]

  Asc, Desc

• 3]

  Desc, Asc

• 4]

  Descending, Ascending