Polynomial time algorithm - first order query, Mathematics

Assignment Help:

For queries Q1 and Q2, we say Q1 is contained in Q2, denoted Q1 ⊆ Q2, iff Q1 (D) ⊆ Q2(D) for every database D.

  • The container problem for a fixed Query Q0 is the following decision problem: Given a query Q, decide whether Q0 ⊆ Q.
  • The containee problem for a fixed query Q0 is the following decision problem: Given a query Q, decide whether Q ⊆ Q0.

Formally prove or disprove the following statements:

(a) For every conjunctive query Q0, there is a polynomial-time algorithm to decide the container problem for Q0 and for given conjunctive queries Q.

(b) For every conjunctive query Q0, there is a polynomial-time algorithm to decide the container problem for Q0 and for given conjunctive queries Q that can be obtained from Q0 by adding some atoms.

(c) For every conjunctive query Q0, there is a polynomial-time algorithm to decide the containee problem for Q0 and for given conjunctive queries Q.

(d) For every first-order Query Q0, there is an algorithm to decide the containee problem for Q0 and for given first-order queries Q. To prove a statement, sketch an algorithm, along with an argument why it is polynomial, if possible. To disprove it, provide an M-hardness or undecidability proof.


Related Discussions:- Polynomial time algorithm - first order query

Chain rule, Chain Rule :   If f(x) and g(x) are both differentiable func...

Chain Rule :   If f(x) and g(x) are both differentiable functions and we describe F(x) = (f. g)(x) so the derivative of F(x) is F′(x) = f ′(g(x)) g′(x).  Proof We will s

Determine the number of combinations, 3 items x, y and z will have 6 differ...

3 items x, y and z will have 6 different permutations however only one combination. The given formular is generally used to determine the number of combinations in a described situ

Sequencing model, theory about solving sequencing problem using graphical m...

theory about solving sequencing problem using graphical method

Adding fractions, please give the answer 1/9+1/3 with working out

please give the answer 1/9+1/3 with working out

Draw the digraph for the partial order, 1. Consider the relation on A = {1,...

1. Consider the relation on A = {1, 2, 3, 4} with relation matrix: Assume that the rows and columns of the matrix refer to the elements of A in the order 1, 2, 3, 4. (a)

Cycloid - parametric equations and polar coordinates, Cycloid The param...

Cycloid The parametric curve that is without the limits is known as a cycloid.  In its general form the cycloid is, X = r (θ - sin θ) Y = r (1- cos θ)  The cycloid pre

Algebra, simplify mn+mp+nq+pq /n+p

simplify mn+mp+nq+pq /n+p

Definition and theorem of derivation, Definition : A function f ( x ) is c...

Definition : A function f ( x ) is called differentiable at x = a if f ′ ( x ) exists & f ( x ) is called differentiable onto an interval if the derivative present for each of the

Matric, fgdg ggghfr hhrhfrf hfrrg jhj hjgg dear friend ghr tu vgu jyyiu ui ...

fgdg ggghfr hhrhfrf hfrrg jhj hjgg dear friend ghr tu vgu jyyiu ui u huik bgyuiiyts husk

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd