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

Complex numbers, How t determine locus of a goven point

How t determine locus of a goven point

Example of hcf, Example  Find the Highest Common Factor of 54, 72...

Example  Find the Highest Common Factor of 54, 72 and 150. First we consider 54 and 72. The HCF for these two quantities is calculated as follows:

What are the three sides of a right triangle, What are the Three Sides of a...

What are the Three Sides of a Right Triangle? Each side of a right triangle can be labeled opposite, adjacent, or hypotenuse, based on its relationship to the right angle and o

Divisiblety test, find the greater value of a and b so that the following e...

find the greater value of a and b so that the following even numbers are divisible by both 3 and 5 : 2ab2a

Variation and proportion, i am not getting what miss has taught us please w...

i am not getting what miss has taught us please will you will help me in my studies

Separable differential equations, We are here going to begin looking at non...

We are here going to begin looking at nonlinear first order differential equations. The first type of nonlinear first order differential equations which we will see is separable di

Sketch the graph of h (t ) = 1 - 5e 1/(t/2), Sketch the graph of h (t ) = ...

Sketch the graph of h (t ) = 1 - 5e  1/(t/2) Solution : Let's primary get a table of values for this function. Following is the sketch. The major point behin

General rule - probability rule, GENERAL RULE A general rule is to sub...

GENERAL RULE A general rule is to subtract the probabilities with an even number of components inside the parentheses and add those with an odd number of components (one or th

Mount everest is 29, Mount Everest is 29,028 ft high. Mount Kilimanjaro is ...

Mount Everest is 29,028 ft high. Mount Kilimanjaro is 19,340 ft high. How much taller is Mount Everest? Subtract Mt. Kilimanjaro's height from Mt. Everest's height; 29,028 - 19

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