HP Intelligent Management Center Standard Software Platform - Manual (Page 659)

Often, data in two different tables can be related by a common field. For
example, a Customers table will have a Customer ID for each customer, and
an Orders table will have the Customer ID of each customer who placed an
order, demonstrating a relationship between tables. The two tables can be
linked by a common field see
Linking tables .
The following diagram displays how two tables can have a relationship:
Aliases
For a variety of reasons, database names and locations get changed. If you
create a report, then change the name or location of a table or file, the Report
Designer must be able to find the new name or location. This is especially
important when you create formulas in your report that access a table that
has been renamed or moved. To fix the reference for a single field would
Crystal Reports 2008 SP3 User's Guide 659
25 Understanding Databases
Databases overview