© Copyright, 2002 Howard F. Arner, Jr. All Rights Reserved. Unauthorized duplication prohibited.
Slide: 27   4/2/2002
Real World
•Trucking company with 60,000,000 records in a physical file.
•60 Logical files
•All logicals begin with company number
•1 Company number
•All queries did not include where company = clause
•No logicals chosen to implement queries because left most key of logicals was not used in restriction