UGC NET CS 2009 Dec-Paper-2
October 16, 2023Data-Structures
October 16, 2023UGC NET CS 2015 June Paper-3
| Question 11 |
The relation schemas R 1 and R 2 form a Lossless join decomposition of R if and only if:
R 1 ∩ R 2 ↠ (R 1 – R 2 )
R 1 → R 2
R 1 ∩ R 2 ↠ (R 2 – R 1 )
(R 2 → R 1 ) ∩ R 2
R 1 ∩ R 2 ↠ (R 1 – R 2 )
R 1 → R 2
R 1 ∩ R 2 ↠ (R 2 – R 1 )
(R 2 → R 1 ) ∩ R 2
| (a) and (b) happens | |
| (a) and (d) happens | |
| (a) and (c) happens | |
| (b) and (c) happens |
Question 11 Explanation:
The decomposition of a relation is said to be lossless if and only if there exists a common attribute which is a primary key in any of the two decomposed relations. In this case statement (a) and statement (c) are satisfying this criteria. Hence option (C) is correct.
Correct Answer: C
Question 11 Explanation:
The decomposition of a relation is said to be lossless if and only if there exists a common attribute which is a primary key in any of the two decomposed relations. In this case statement (a) and statement (c) are satisfying this criteria. Hence option (C) is correct.
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