--%>
Assignment Help - homework help

Containee problem

For queries Q1 and Q2, we say Q1 is containedin Q2, denoted Q1 C Q2, iff Q1(D) C Q2(D) for every database D.

The container problern for a fixed Query Qo is the following decision problem:
Given a query Q, decide whether Qo C Q.

The containee probletn for a fixed guery Qo is the following decision problem:
Given a query Q, decide whether Q C Qo.

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 Qo by adding some atoms.

(c) For every conjunctive euery Qo, there is a polynomial-time algorithm to decide the containee problem for Q0 and for grven conjunctive queries  Q.

(d) For every flrst-order Query Q0, there is an algorithm to decide the containee problem for Qo 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 Questions in Mathematics

  • Q : Who developed a rigorous theory for

    Who developed a rigorous theory for Brownian motion?

    		•
  • Q : State Measuring complexity Measuring

    Measuring complexity: Many algorithms have an integer n, or two integers m and n, as input - e.g., addition, multiplication, exponentiation, factorisation and primality testing. When we want to describe or analyse the `easiness' or `hardness' of the a

    		•
  • Q : First-order formulas over the

    Consider the unary relational symbols P and L, and the binary relational symbol On, where P(a) and I(a) encode that a is apoint and a (sraight) line in the 2-dimensional space, respectively, while On(a,b) encodes  that a is a point, b is a line, and o lies on b.

    		•
  • Q : Numerical Analysis Hi, I was wondering

    Hi, I was wondering if there is anyone who can perform numerical analysis and write a code when required. Thanks

    		•
  • Q : The mean of the sampling distribution

    1. Caterer determines that 87% of people who sampled the food thought it was delicious. A random sample of 144 out of population of 5000 taken. The 144 are asked to sample the food. If P-hat is the proportion saying that the food is delicious, what is the mean of the sampling distribution p-hat?<

    		•
  • Q : Relationships Between Data Introduction

    Relationships Between Data - Introduction to Linear Regression Simple Regression Notes If you need guidance in terms of using Excel to run regressions, check pages 1 - 10 of the Excel - Linear Regression Tutorial posted to th

    		•
  • Q : Explain a rigorous theory for Brownian

    Explain a rigorous theory for Brownian motion developed by Wiener Norbert.

    		•
  • Q : Pig Game Using the PairOfDice class

    Using the PairOfDice class design and implement a class to play a game called Pig. In this game the user competes against the computer. On each turn the player rolls a pair of dice and adds up his or her points. Whoever reaches 100 points first, wins. If a player rolls a 1, he or she loses all point

    		•
  • Q : Simulation with Arena An office of

    An office of state license bureau has two types of arrivals. Individuals interested in purchasing new plates are characterized to have inter-arrival times distributed as EXPO(6.8) and service times as TRIA(808, 13.7, 15.2); all times are in minutes. Individuals who want to renew or apply for a new d

    		•
  • Q : Formal logic2 It's a problem set, they

    It's a problem set, they are attached. it's related to Sider's book which is "Logic to philosophy" I attached the book too. I need it on feb22 but feb23 still work

    		•