Quiz Discussion

Using which language can a user request information from a database?

• 1]

  Query

• 2]

  Relational

• 3]

  Structural

• 4]

  Compiler

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_____ 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

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;

   

Course(course_id,sec_id,semester)

Here the course_id,sec_id and semester are __________ and course is a _________

• 1]

  Relations, Attribute

• 2]

  Attributes, Relation

• 3]

  Tuple, Relation

• 4]

  Tuple, Attributes

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

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

Database __________ which is the logical design of the database, and the database _______ which is a snapshot of the data in the database at a given instant in time.

• 1]

  Instance, Schema

• 2]

  Relation, Schema

• 3]

  Relation, Domain

• 4]

  Schema, Instance

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