Quiz Discussion

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

• 1]

  Different

• 2]

  Indivisbile

• 3]

  Constant

• 4]

  Divisible

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

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 _______ 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

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

The ________ clause is used to list the attributes desired in the result of a query.

• 1]

  Where

• 2]

  Select

• 3]

  From

• 4]

  Distinct

Department (dept name, building, budget) and Employee (employee_id, name, dept name, salary)
Here the dept_name attribute appears in both the relations. Here using common attributes in relation schema is one way of relating ___________ relations.

• 1]

  Attributes of common

• 2]

  Tuple of common

• 3]

  Tuple of distinct

• 4]

  Attributes of distinct

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

’_____’ matches any string of ______ three characters. ’_____%’ matches any string of at ______ three characters.

• 1]

  Atleast, Exactly

• 2]

  Exactly, Atleast

• 3]

  Atleast, All

• 4]

  All, Exactly

The_____ operation allows the combining of two relations by merging pairs of tuples, one from each relation, into a single tuple.

• 1]

  Select

• 2]

  Join

• 3]

  Union

• 4]

  Intersection