UGC NET CSE | June 2019 | Part 2 | Question: 31

Question

Which of the following has same expressive power with regard to relational query language?

1. Rational algebra and domain relational calculus
2. Relational algebra and tuples relational calculus
3. Relational algebra and domain relational calculus restricted to safe expression
4. Relational algebra and tuples relational calculus restricted to safe expression

• A. i and ii only
• B. iii and iv only
• C. i and iii only
• D. ii and iv only

Comments

2

Relational Algebra equivalent in expressing power to A. TRC B. DRC restricted to safe Operation.

Answer 1

The expressive power of TRC,DRC is equivalent to relational aljebra .hence the option B is correct.

Answer 2

please refer here: 1)https://gateoverflow.in/3554/gate2006-it-15

                              2)https://gateoverflow.in/825/gate2002-1-20

Answer 3

Ans: (B) c and d only. 

see here: https://gateoverflow.in/3554/gate2006-it-15

Answer 4

Relational algebra has same expressive power as safe relational calculus (safe tuple relational calculus and safe domain relational calculus.

So B is correct.