The Gateway to Computer Science Excellence
+2 votes

Suppose ORACLE relation R(A,B) currently has tuples {(1,2), (1,3), (3,4)} and relation S(B,C) currently has {(2,5), (4,6), (7,8)}.Consider the following two SQL queries SQ1 and SQ2:

SQ1:    Select * From R Full Join S On R.B=S.B;
SQ2:    Select * From R Inner Join S On R.B=S.B;

The numbers of tuples in the result of the SQL query SQ1 and the SQL query SQ2 are given by:

  1. 2 and 6 respectively
  2. 6 and 2 respectively
  3. 2 and 4 respectively
  4. 4 and 2 respectively
in Databases by Veteran
recategorized by | 2.5k views

2 Answers

+4 votes
Best answer
inner join gives the record of two tables based on = condition

here R.B=S.B holds for 2 records when B=2 and B=4 hence its result w hence 2

for SQ2 Full Join or full outer join gives the result of left outer join(all rows of left table whether there is match or not) + right outer join( all rows of right table whether there is match or not with the left) now both table has 3 records but there are 2 match and 2 mismatch

hence SQ1 will give 4 records

so ans is choice D
by Boss
selected by
+1 vote
I think inner join is same as natural join only difference Herr column name is given..

So it will return 2 tuples

1 2 5 and 3 4 6 from R.

Full join is similar to full outer join..

So it will result 4 tuples..

1 2 5 , 3 4 6, 1 3 null , null 7 8
by Boss

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
52,218 questions
59,890 answers
118,128 users