The Gateway to Computer Science Excellence
First time here? Checkout the FAQ!
x
+22 votes
818 views

With regards to the expressive power of the formal relational query languages, which of the following statements is true?

  1. Relational algebra is more powerful than relational calculus
  2. Relational algebra has the same power as relational calculus
  3. Relational algebra has the same power as safe relational calculus
  4. None of the above
asked in Databases by Veteran (68.8k points) | 818 views

2 Answers

+19 votes
Best answer

Answer: C

Relational algebra has the same power as safe relational calculus as:

  • A query can be formulated in safe Relational Calculus if and only if it can be formulated in Relational Algebra.
answered by Veteran (35.8k points)
edited by
Reference ?
Difference between safe relational calculus and relational calculus
you may find an answer in korth book
+3 votes

Option "B" is also correct but option "C" is more appropriate because Relational calculus have some unsafe operations and because of those unsafe operations sometimes it may fall in ∞(infinite) loop.

so relational algebra has the same power as safe relational calculus

answered by (497 points)
Answer:

Related questions



Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true

32,442 questions
39,188 answers
108,800 comments
36,561 users