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

What is the formula to know total area square shaped quilt, Cathy is formin...

Cathy is forming a quilt out of fabric panels that are 6 in through 6 in. She needs to know the total area of her square-shaped quilt. Which formula will she use? The area of a

Learning to count in maths, Here we learn: 1) Discussed what counting me...

Here we learn: 1) Discussed what counting means, and stressed that it is not the ability to recite number names. 2) Talked about the need for a child to understand several pr

Word problems, A patient will receive hemodialysis for 2.5 hours. The amoun...

A patient will receive hemodialysis for 2.5 hours. The amount of fluid removed per hour is 1.4 liters. The total amount removed in liters, will be

Interpretation of r – problems in interpreting r values, Interpretation of ...

Interpretation of r - Problems in interpreting r values A high value of r as +0.9 or - 0.9 only shows a strong association among the two variables but doesn't imply that th

Simplify, X^2 – y^2 – 2y - 1

X^2 – y^2 – 2y - 1

Mashed patatos, I have 6 cups of patatos that I have to share with 13 frien...

I have 6 cups of patatos that I have to share with 13 friends write that as the nearest hundredth

Long distance calls cost x cent how much 5-minute call cost, A long distanc...

A long distance calls costs x cents for the first minute and y cents for every additional minute. How much would a 5-minute call cost? The cost of the call is x cents plus y ti

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