Quiz Discussion

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

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

• 1]

  Query

• 2]

  Relational

• 3]

  Structural

• 4]

  Compiler

The _______operation performs a set union of two “similarly structured” tables

• 1]

  Union

• 2]

  Join

• 3]

  Product

• 4]

  Intersect

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

• 1]

  Column

• 2]

  Key

• 3]

  Row

• 4]

  Entry

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

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

_____ operator is used for appending two strings.

• 1]

  &

• 2]

  %

• 3]

  ||

• 4]

  _

The result which the operation contains all pairs of tuples from the two relations, regardless of whether their attribute values match.

• 1]

  Join

• 2]

  Cartesian product

• 3]

  Intersection

• 4]

  Set difference

In SQL the spaces at the end of the string are removed by _______ function.

• 1]

  Upper

• 2]

  String

• 3]

  Trim

• 4]

  Lower

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