Statement 1: Referential Integrity refers to the validity of an
attribute domain. True or False.
Statement...
Statement 1: Referential Integrity refers to the validity of an
attribute domain. True or False.
Statement 2: In SQL, when Create a table, the foreign key must
be not null. True or False.
a) Both are True
b) 1 is True, 2 is False
c) 1 is False, 2 is True
d) Both are False
Here are SQL declarations for three tables R, S, and T:
CREATE TABLE R(e INT PRIMARY...
Here are SQL declarations for three tables R, S, and T:
CREATE TABLE R(e INT PRIMARY KEY, f INT);
CREATE TABLE S(c INT PRIMARY KEY, d INT REFERENCES R(e) ON DELETE CASCADE);
CREATE TABLE T(a INT PRIMARY KEY, b INT REFERENCES S(c) ON DELETE CASCADE);
Suppose R(e,f) contains tuples
(1,0), (2,4), (3,5), (4,3), and (5,7).
Suppose S(c,d) contains tuples
(1,5), (2,2), (3,3), (4,5), and (5,4).
Suppose T(a,b) contains tuples
(0,2), (1,2), (2,3), (3,4), and (4,4).
As a result of the...
Determine whether the binary relation R on {a, b,
c} where R={(a, a), (b, b)), (c,...
Determine whether the binary relation R on {a, b,
c} where R={(a, a), (b, b)), (c, c), (a, b), (a,
c), (c, b) } is:
a.
reflexive, antisymmetric, symmetric
b.
transitive, symmetric, antisymmetric
c.
antisymmetric, reflexive, transitive
d.
symmetric, reflexive, transitive
Please quesiton on database function
dependency: Suppose we have relation R (A, B, C, D, E),...
Please quesiton on database function
dependency: Suppose we have relation R (A, B, C, D, E), with some
set of FD’s , and we wish to project those FD’s onto relation S (A,
B, C). Give the FD’s that hold in S if the FD’s for R are:
c) AB --> D, AC --> E, BC -->
D, D --> A, and E --> B.
d) A --> B, B --> C, C --> D,
D --> E, and E...
4. Consider the relation schema R(ABCDE) with the set of
functional dependencies F={B→E, A→B, DE→C, D→A,...
4. Consider the relation schema R(ABCDE) with the set of
functional dependencies F={B→E, A→B, DE→C, D→A, C→AE}. For the
following relations resulting from a possible decomposition of R,
identify the non-trivial functional dependencies which can be
projected to each of the decomposed relations.
a) S(ABC)
b) T(BCE)
c) U(ABDE
Suppose we have the following relation R with composite primary
key {A,B} together with the set...
Suppose we have the following relation R with composite primary
key {A,B} together with the set FD of functional
dependencies:
R(A,B,C,D,E,F,G).
FD = { C -> G, E -> B, A -> D, AB -> C, AB -> D, AB
-> E. AB -> F, AB -> G }
Draw the initial dependency diagram using the above
information.
The relation from part a) is in first normal form. Using the
techniques described in the lecture, convert it to 2NF by...
Consider the following set S = {(a,b)|a,b ∈ Z,b 6= 0} where Z
denotes the integers....
Consider the following set S = {(a,b)|a,b ∈ Z,b 6= 0} where Z
denotes the integers. Show that the relation (a,b)R(c,d) ↔ ad = bc
on S is an equivalence relation. Give the equivalence class
[(1,2)]. What can an equivalence class be associated with?
In Locality Sensitive Hashing, we divide signature columns to b
bands where there are r elements...
In Locality Sensitive Hashing, we divide signature columns to b
bands where there are r elements in each band for each column.
Consider two columns C1 and C2 of length m = br. Suppose that for
each i = 1, .., m, the probability that C1(i) = C2(i) is equal to s
independently from other elements. Note that s is in fact the
similarity of the two columns.
(a) Show that the probability that the two columns are equal in...