GATE CSE
First time here? Checkout the FAQ!
x
+9 votes
923 views

SELECT operation in SQL is equivalent to

  1. The selection operation in relational algebra
  2. The selection operation in relational algebra, except that SELECT in SQL retains duplicates
  3. The projection operation in relational algebra
  4. The projection operation in relational algebra, except that SELECT in SQL retains duplicates
asked in Databases by Veteran (29.1k points)   | 923 views

1 Answer

+17 votes
Best answer

option D is correct because SELECT operation in SQL is equivalent to The projection operation in relational algebra, except that SELECT in SQL retains duplicates but projection gives only distinct  

answered by Loyal (4.8k points)  
selected by
@Arjun Sir: This question is an perfect example where GATE gets really tricky. Most will write Option B.

Now such questions really clear the concepts. This should be marked as tricky. I'd ask you to add one more tag apart from easy normal hard a TRICKY tag. there are tons of such tricky questions. Pondering over these would help a lot of Gate Aspirants.
Actually I wouldn't mark this as tricky as GATE has more trickier questions in store :)

But, whichever question you find like this, you can mark as "favorite" and this can be useful during exam time for quick reference.
any source/material for explanation!


Top Users Mar 2017
  1. rude

    4758 Points

  2. sh!va

    3014 Points

  3. Rahul Jain25

    2910 Points

  4. Kapil

    2636 Points

  5. Debashish Deka

    2450 Points

  6. 2018

    1514 Points

  7. Vignesh Sekar

    1422 Points

  8. Akriti sood

    1322 Points

  9. Bikram

    1286 Points

  10. Sanjay Sharma

    1076 Points

Monthly Topper: Rs. 500 gift card

21,494 questions
26,815 answers
61,058 comments
23,069 users