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

Estimate the value of x and y in liner equation, ( a+2b)x + (2a - b)y = 2...

( a+2b)x + (2a - b)y = 2, (a - 2b)x + (2a +b)y = 3 (Ans: 5b - 2a/10ab , a + 10b/10ab ) Ans: 2ax + 4ay = y , we get 4bx - 2by = -1 2ax+ 4ay = 5  4bx- 2by = - 1

F distribution, The F Distribution The F distribution is the dis...

The F Distribution The F distribution is the distribution of the ratio of 2 random variables. Both random variables have yet another distribution, called the c 2 Distri

Calculus, the limit of f(x) as x approaches 5 is equal to 7. write the defi...

the limit of f(x) as x approaches 5 is equal to 7. write the definition of limit as it applies to f at this point

Evaluate the linear equation, Evaluate the linear equation: Solve the ...

Evaluate the linear equation: Solve the equation ax - b = c for x in terms of a, b, and c. Solution: Step 1. Using Axiom 1, add b to both sides of the equation. a

Demerits and merit-the mode, The mode Merits i.  This can be dete...

The mode Merits i.  This can be determined from incomplete data given the observations along with the highest frequency are already known ii.  The mode has some applic

Estimate the total cost of the books, Frederick bought six books which cost...

Frederick bought six books which cost d dollars each. What is the total cost of the books? Frederick would multiply the number of books, 6, through how much each one costs, d.

Geometric applications to the cross product, Geometric Applications to the ...

Geometric Applications to the Cross Product There are a so many geometric applications to the cross product also.  Assume we have three vectors a → , b → and c → and we make

Calculate the acceleration time, Question A 22 kW, 3-phase, 415 V, 40 A,...

Question A 22 kW, 3-phase, 415 V, 40 A, 50 Hz, 960 rpm, 0.88 PF squirrel cage induction motor drives a pump. The total inertia of the drives system is 1.2 kg-m2. Determine th

Prove the boolean expression, Prove the subsequent Boolean expression: ...

Prove the subsequent Boolean expression: (x∨y) ∧ (x∨~y) ∧ (~x∨z) = x∧z Ans: In the following expression, LHS is equal to:   (x∨y)∧(x∨ ~y)∧(~x ∨ z) = [x∧(x∨ ~y)] ∨ [y∧(x∨

Surds and logarithms, what are these all about and could i have some exampl...

what are these all about and could i have some examples of them please

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