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

Debate over answer to an equation..., The math equation is written exactly ...

The math equation is written exactly this way: 0+50x1-60-60x0+10=??? The answer I get is 10 and others say 0 0+50=50 50x1=50 50-60=-10 -10-60=-70 -70x0=0 0+10=10

Graph and algebraic methods , To answer each question, use the function t(r...

To answer each question, use the function t(r) = d , where t is the time in hours, d is the distance in miles, and r is the rate in miles per hour. a. Sydney drives 10 mi at a c

Average function value, Average Function Value The average value of a ...

Average Function Value The average value of a function f(x) over the interval [a,b] is specified by, f avg = (1/b-a) a ∫ b f(x) dx Proof We know that the average

How to grow your brand with existing customers., "To grow your brand, you n...

"To grow your brand, you need to encourage your existing customers to buy your product a liitle more often. It is far more important to maximise the number of times your buyers buy

Geography, How do you find the maxima or minima on a parabolic graph?

How do you find the maxima or minima on a parabolic graph?

Trig substitutions - integration techniques, Trig Substitutions - Integrati...

Trig Substitutions - Integration techniques As we have completed in the last couple of sections, now let's start off with a couple of integrals that we should previously be

Differential equation (dy/dx) +x^2 = x^2*e^(3y), The general solution of th...

The general solution of the differential equation (dy/dx) +x^2 = x^2*e^(3y). Solution)(dy/dx) +x^2 = x^2*e^(3y) dy/dx=x 2 (e 3y -1) x 2 dx=dy/(e 3y -1) this is an elementar

Trapezoid rule - approximating definite integrals, Trapezoid Rule - Approxi...

Trapezoid Rule - Approximating Definite Integrals For this rule we will do similar set up as for the Midpoint Rule. We will break up the interval [a, b] into n subintervals of

Objectives to knowing your maths learner, Objectives After studying th...

Objectives After studying this unit, you should be able to briefly describe the developmental stages of children's thinking and learning processes; assess the levels

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