Quiz Discussion

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

Which one of the following is procedural language?

• 1]

  Domain relational calculus

• 2]

  Tuple relational calculus

• 3]

  Relational algebra

• 4]

  Query language

SELECT * FROM employee WHERE dept_name="Comp Sci";

In the SQL given above there is an error . Identify the error.

• 1]

  Dept_name

• 2]

  Employee

• 3]

  “Comp Sci”

• 4]

  From

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

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

• 1]

  Query

• 2]

  Relational

• 3]

  Structural

• 4]

  Compiler

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 term _______ is used to refer to a row.

• 1]

  Attribute

• 2]

  Tuple

• 3]

  Field

• 4]

  Instance

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

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