334 views

1 Answer

1 votes
1 votes
The second query always returns 0.

Thus, the table returned by second query consists of 1 tuple.

 

Now, exists( table containing single tuple)= true for every employee of 1st relation.

 

Thus, bove query will return all the tuples of the 1st relation.
Answer:

Related questions

0 votes
0 votes
1 answer
1
sumit chakraborty asked Nov 26, 2017
1,158 views
In 2PL protocol if all exclusive locks are acquired by transaction in increasing order of their accesses then is the 2PL starvation free ?
0 votes
0 votes
1 answer
3