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

Design an automaton that accepts only even numbers, Design an automaton tha...

Design an automaton that accepts just only even numbers of 0s and even number of 1's. Ans: The needed automata that accepts even number of 0's and even number of 1's is specifi

#i need help on my math homework its on algabraitle.., The question is: If ...

The question is: If 0.2 x n = 1.4,what is the value of n.

Logarithms, find any integer from 1-128 on a logarithmic scale

find any integer from 1-128 on a logarithmic scale

Determine the mean of the subsequent numbers, Determine the mean of the sub...

Determine the mean of the subsequent numbers: Example: Determine the mean of the subsequent numbers: 5, 7, 1, 3, 4 Solution: where x'          =

Sin3? = cos2? find the most general values of ?, sin3θ = cos2θ find the mos...

sin3θ = cos2θ find the most general values of θ satisfying the equatios? sinax + cosbx = 0 solve ? Solution)  sin (3x) = sin(2x + x) = sin(2x)cos(x) + cos(2x)sin(x) = 2sin(x)cos(

How organize data by circle graphs, Q. How organize data by Circle Graphs? ...

Q. How organize data by Circle Graphs? Ans. Circle graphs, or pie charts, are another way of organizing data sets into an easy-to-read format. They make it very easy to c

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