Consider the following relations. • Student (zno, sname, age) · Enroll (zno, cno) • Course (cno, cname, semester) Given the following SQL, which one is the best index to improve the query performance. SELECT S.zno, S.sname, count(cno) FROM Student S, Enroll E WHERE S.zno = E.zno GROUP BY S.zno HAVING count(cno) >10;

Consider the following relations. • Student (zno, sname, age) · Enroll (zno, cno) • Course (cno, cname, semester) Given the following SQL, which one is the best index to improve the query performance. SELECT S.zno, S.sname, count(cno) FROM Student S, Enroll E WHERE S.zno = E.zno GROUP BY S.zno HAVING count(cno) >10;

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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