Consider the following Relation instance of R1(A, B, C, D): A D Null Null 1 Null Null 1 1 Null 1 2 4 2 3 2 4 6 1 3 2 We also have relation R2 (E, F) which has no tuples. Suppose the attributes of R1 and R2 are all integers. How many tuples will there be in relation R2 after we perform the following 3 insertion statements? Insert into R2 (select B, sum(A) from R group by B); Insert into R2 (select A, sum(D) from R where D < 5 group by A); Insert into R2 (select C, sum(A) from R where A = A group by C); Answer: 3. 3.

Consider the following Relation instance of R1(A, B, C, D): A D Null Null 1 Null Null 1 1 Null 1 2 4 2 3 2 4 6 1 3 2 We also have relation R2 (E, F) which has no tuples. Suppose the attributes of R1 and R2 are all integers. How many tuples will there be in relation R2 after we perform the following 3 insertion statements? Insert into R2 (select B, sum(A) from R group by B); Insert into R2 (select A, sum(D) from R where D < 5 group by A); Insert into R2 (select C, sum(A) from R where A = A group by C); Answer: 3. 3.

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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