formal relational query languages

MCQsQuestion.com has 15 Question/Answers about Topic formal relational query languages

Operation of projection is a

Operation of projection is a
  • A. Dimensional operations
  • B. Multidimensional operations
  • C. Unary operations
  • D. Binary operations
  • Correct Answer: Option C

It must be ensured that union operation is taken between

It must be ensured that union operation is taken between
  • A. Incompatible relations
  • B. Compatible relations
  • C. Consistent relations
  • D. Integrated relation
  • Correct Answer: Option B

Join operation that takes all tuples in left relation that is not matching with any tuple in right relation, is called

Join operation that takes all tuples in left relation that is not matching with any tuple in right relation, is called
  • A. Right outer join
  • B. Full outer join
  • C. Left outer join
  • D. Natural outer join
  • Correct Answer: Option C

Operation that permits to find tuples that are in one relation but not in another, is said to be

Operation that permits to find tuples that are in one relation but not in another, is said to be
  • A. Union
  • B. Set difference
  • C. Projection
  • D. Selection
  • Correct Answer: Option B

Relational algebra is a

Relational algebra is a
  • A. Formal language
  • B. Informal language
  • C. Structured language
  • D. Procedural language
  • Correct Answer: Option A

At result of left outer join, present information is from the

At result of left outer join, present information is from the
  • A. Right relation
  • B. Left relation
  • C. Combination of relations
  • D. Left and right relation
  • Correct Answer: Option B

A query that involves a Cartesian product includes a

A query that involves a Cartesian product includes a
  • A. Projection operation
  • B. Selection operation
  • C. Union operation
  • D. Set-intersection operation
  • Correct Answer: Option B

Attributes are listed that are desired to appear in result list as a subscript to

Attributes are listed that are desired to appear in result list as a subscript to
  • A. beta
  • B. sigma
  • C. gamma
  • D. pi
  • Correct Answer: Option D

Expression r -s represents a

Expression r -s represents a
  • A. Arity
  • B. Unity
  • C. Projection
  • D. Set-difference
  • Correct Answer: Option D

Rename operation is expressed by lower case Greek letter, named

Rename operation is expressed by lower case Greek letter, named
  • A. alpha
  • B. beta
  • C. sigma
  • D. rho
  • Correct Answer: Option D

Instead of rename operation it is possible for attributes to use a

Instead of rename operation it is possible for attributes to use a
  • A. Positional notation
  • B. Nonpositional notation
  • C. Fixed notation
  • D. Logical notation
  • Correct Answer: Option A

Theta join operation is a variant of the

Theta join operation is a variant of the
  • A. Natural join
  • B. Compound join
  • C. Composite join
  • D. Assignment join
  • Correct Answer: Option A

Operations with ability to express queries that cannot be expressed by basic relational-algebra operations, is known as

Operations with ability to express queries that cannot be expressed by basic relational-algebra operations, is known as
  • A. Compound relational-algebra
  • B. Composite relational-algebra
  • C. Embedded relational-algebra
  • D. Extended relational-algebra
  • Correct Answer: Option D

A join operation that deals with missing information, is said to be

A join operation that deals with missing information, is said to be
  • A. Natural join
  • B. Inner join
  • C. Outer join
  • D. Full join
  • Correct Answer: Option C

Select project, and rename operations are called unary operations, because they operate on

Select project, and rename operations are called unary operations, because they operate on
  • A. One tuple only
  • B. One relation only
  • C. One attribute only
  • D. One instance only
  • Correct Answer: Option B