Question

5. Q5: Consider S from Q2. Is the decomposition of S into S1(E,G,F) and S2(A,B,C,D,G) a lossless join decomposition? Choose one of the following queries as your answer: SELECT 'lossy'; SELECT 'lossless'; Submit your chosen query in file Q5.sql. 6. Q6: Consider relation W(A,B,C,D), different than the relations in prior questions. We are told that W is in BCNF, and that exactly 3 out of the 4 FDs listed below hold for W. Choose the FD that W does not satisfy. 1: C ? ABD 2: AD ? C 3: B ? D 4: BD ? A Format your answer in a query as follows: SELECT answer; where answer is 1, 2, 3, or 4, e.g., SELECT 1. Submit your answer as a query in file Q6.sql. 7. Q7: Assume a relation X(A,B,C) defined by the following statement: CREATE TABLE X (A int, B int, C int); The relation is currently empty. You have to insert exactly 3 tuples into the relation, without duplicates, to create a data instance in which the functional dependency A ? BC holds and the functional dependencies B ? C and C ? B do not hold. Submit your 3 insert statements in file Q7.sql.

          5. Q5: Consider S from Q2. Is the decomposition of S into S1(E,G,F) and S2(A,B,C,D,G)
a lossless join decomposition?

Choose one of the following queries as your answer:

SELECT 'lossy';

SELECT 'lossless';

Submit your chosen query in file Q5.sql.

6. Q6: Consider relation W(A,B,C,D), different than the relations in prior questions. We
are told that W is in BCNF, and that exactly 3 out of the 4 FDs listed below hold for
W. Choose the FD that W does not satisfy.

1: C ? ABD
2: AD ? C
3: B ? D
4: BD ? A

Format your answer in a query as follows:

SELECT answer;

where answer is 1, 2, 3, or 4, e.g., SELECT 1. Submit your answer as a query in file
Q6.sql.

7. Q7: Assume a relation X(A,B,C) defined by the following statement:

CREATE TABLE X (A int, B int, C int);

The relation is currently empty. You have to insert exactly 3 tuples into the relation,
without duplicates, to create a data instance in which the functional dependency A ?
BC holds and the functional dependencies B ? C and C ? B do not hold.

Submit your 3 insert statements in file Q7.sql.

5. Q5: Consider S from Q2. Is the decomposition of S into S1(E,G,F) and S2(A,B,C,D,G)
a lossless join decomposition?

Choose one of the following queries as your answer:

SELECT 'lossy';

SELECT 'lossless';

Submit your chosen query in file Q5.sql.

6. Q6: Consider relation W(A,B,C,D), different than the relations in prior questions. We
are told that W is in BCNF, and that exactly 3 out of the 4 FDs listed below hold for
W. Choose the FD that W does not satisfy.

1: C ? ABD
2: AD ? C
3: B ? D
4: BD ? A

Format your answer in a query as follows:

SELECT answer;

where answer is 1, 2, 3, or 4, e.g., SELECT 1. Submit your answer as a query in file
Q6.sql.

7. Q7: Assume a relation X(A,B,C) defined by the following statement:

CREATE TABLE X (A int, B int, C int);

The relation is currently empty. You have to insert exactly 3 tuples into the relation,
without duplicates, to create a data instance in which the functional dependency A ?
BC holds and the functional dependencies B ? C and C ? B do not hold.

Submit your 3 insert statements in file Q7.sql.

Added by Samantha E.

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