Q4 Consider the given schema and answer the questions.Q(a,b), R(b,c), S(b,d), T(b,e).a) For the following SQL query, give two equivalent logical plans in relationalalgebra such that one is likely to be more efficient than the other. Indicate whichone is likely to be more efficient. Explain.Q. aQ, RQ.b = R.b AND R.c = 3SELECTFROMWHEREb) By using the left-deep tree plan favored by optimizers. Write a left-deep tree planfor the below given SQL query. Use relational algebra; be sure to use parenthesesto indicate the order that the joins should be performed.SELECTQ, R, S, TQ.b = R.b AND R.b = S.b AND S.b = T.bFROMWHERE

Answer: a) i. πa(σc=3(Q ◃▹b=b (R))) ii. πa(Q ◃▹b=b σc=3(R)))

Consider the given schema and answer the questions. Q(a,b), R(b,c), S(b,d), T(b,e). a) For the following SQL query, give two equivalent logical plans in relational algebra such that one is likely to be more efficient than the other. Indicate which one is likely to be more efficient. Explain. SELECT FROM WHERE Q. a Q, R Q.b = R.b AND R.c = 3 b) By using the left-deep tree plan favored by optimizers. Write a left-deep tree plan for the below given SQL query. Use relational algebra; be sure to use parentheses to indicate the order that the joins should be performed. SELECT FROM Q, R, S, T Q.b = R.b AND R.b = S.b AND S.b =T.b WHERE

Consider the given schema and answer the questions. Q(a,b), R(b,c), S(b,d), T(b,e). a) For the following SQL query, give two equivalent logical plans in relational algebra such that one is likely to be more efficient than the other. Indicate which one is likely to be more efficient. Explain. SELECT FROM WHERE Q. a Q, R Q.b = R.b AND R.c = 3 b) By using the left-deep tree plan favored by optimizers. Write a left-deep tree plan for the below given SQL query. Use relational algebra; be sure to use parentheses to indicate the order that the joins should be performed. SELECT FROM Q, R, S, T Q.b = R.b AND R.b = S.b AND S.b =T.b WHERE

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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