Answered: 1. PART Evaluation and optimization: A…

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

See similar textbooks

Related questions

Concept explainers

Question

Transcribed Image Text:1. PART Evaluation and optimization: A schema of the ski shop information system is given: Customer (cid, name, surname, address, telephone); Employee (eid, name, surname, address, telephone); Purchase (pid, sid, cid, eid, date); Skiis (sid, brand, model, length, hardness) Additional information is given: |Customer] =150 pages, 40 records/page | Employee | = 2 pages, 40 records/page | Purchase | = 2000 pages, 100 records/page |Skiis | = 250 pages, 30 records/page Buffer can store up to 2500 pages. Let's assume that the following indices are now set on the schema from the previous task: Level 2 B+ index on the attribute Purchase.date Hash index on the attribute Skiis.sid - Our DBMS has the following algorithms to perform the join: Hash join - Index nested loops join Sort-merge join Translate the following SQL query into relational algebra and find the plan that reads the fewest pages or blocks: SELECT Skiis.model, Skiis.length FROM Skiis JOIN Purchase ON (Skiis.sid = Purchase.sid) WHERE Skiis.brand = 'Elan' AND Purchase.date > '31.12.2023'

Expert Solution

Step by step

Solved in 3 steps with 2 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, computer-science and related others by exploring similar questions and additional content below.

Similar questions