© Copyright, 2002 Howard F.
Arner, Jr. All Rights Reserved. Unauthorized duplication prohibited.
What Logicals can be Used?
•SQL can use most logicals where
the file is marked as relational
•However, SQL will rarely use
logicals with select omit criteria**
•Join logicals are
almost always a bad idea**
•Always initially select
against the physical, do not name the logical in the from
clause