Write a Theta join expression that has the same effect of a natural
join between R...
Write a Theta join expression that has the same effect of a natural
join between R (A, B, C, D) and S (C, D, E, F)
2. Define a relation R on pairs of real numbers as follows: (a,
b)R(c, d) iff...
2. Define a relation R on pairs of real numbers as follows: (a,
b)R(c, d) iff either a < c or both a = c and b ≤ d. Is R a
partial order? Why or why not? If R is a partial order, draw a
diagram of some of its elements.
3. Define a relation R on integers as follows: mRn iff m + n is
even. Is R a partial order? Why or why not? If R is...
Here are two relations:
R(A,B): {(0, 1), (2,3), (0, 1), (2,4), (3,4)}
S(B, C): {(0, 1),...
Here are two relations:
R(A,B): {(0, 1), (2,3), (0, 1), (2,4), (3,4)}
S(B, C): {(0, 1), (2, 4), (2, 5), (3, 4), (0, 2), (3, 4)}
Compute the following: a) 11'A+B.A2,B2(R); b) 71'B+l,C-l(S); c)
TB,A(R); d) TB,c(S); e) J(R); f) J(S); g) /A, SUM(Bj(R); h)
IB.AVG(C)(S'); ! i) !A(R); ! j) IA,MAX(C)(R t:><1 S); k) R ~L
S; I) R ~H S; m) R ~ S; n) R ~R.B<S.B S.
I want to know the solution for j to m
Given a relation R(A, B, C, D, E) with the following FD
Set
FD = {...
Given a relation R(A, B, C, D, E) with the following FD
Set
FD = { A→C, B→C, C→D, DE→A, CE→A}
Suppose we decompose it into R1(A, D), R2(A, B), R3(B, E), R4(C, D,
E) and R5(A, E), is it a lossless decomposition? Show your
proof.
Give direct and indirect proofs of:
(a) a → b, c → b, d → (a...
Give direct and indirect proofs of:
(a) a → b, c → b, d → (a ∨ c), d ⇒ b.
(b) (p → q) ∧ (r → s),(q → t) ∧ (s → u), ¬(t ∧ u), p → r ⇒
¬p.
(c) p → (q → r), ¬s\/p, q ⇒ s → r.
(d) p → q, q → r, ¬(p ∧ r), p ∨ r ⇒ r.
(e) ¬q, p → q, p ∨ t ⇒ t...