Quiz Discussion

SELECT name
FROM instructor
WHERE salary <= 100000 AND salary >= 90000;

This query can be replaced by which of the following ?

• 1]

  SELECT name
  FROM instructor
  WHERE salary BETWEEN 90000 AND 100000;

   

• 2]

  SELECT name
  FROM employee
  WHERE salary <= 90000 AND salary>=100000;

   

• 3]

  SELECT name
  FROM employee
  WHERE salary BETWEEN 90000 AND 100000;

   

• 4]

  SELECT name
  FROM instructor
  WHERE salary BETWEEN 100000 AND 90000;

   

The _________ provides a set of operations that take one or more relations as input and return a relation as an output.

• 1]

  Schematic representation

• 2]

  Relational algebra

• 3]

  Scheme diagram

• 4]

  Relation flow

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

Which one of the following is procedural language?

• 1]

  Domain relational calculus

• 2]

  Tuple relational calculus

• 3]

  Relational algebra

• 4]

  Query language

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

A domain is atomic if elements of the domain are considered to be ____________ units.

• 1]

  Different

• 2]

  Indivisbile

• 3]

  Constant

• 4]

  Divisible

The term attribute refers to a ___________ of a table.

• 1]

  Record

• 2]

  Column

• 3]

  Tuple

• 4]

  Key

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 name
FROM instructor
WHERE dept name = ’Physics’
ORDER BY name;

By default, the order by clause lists items in ______ order.

• 1]

  Descending

• 2]

  Any

• 3]

  Same

• 4]

  Ascending