When there is more than one link,
Crystal Reports needs to know in what order it should process
the links. By default, the processing order matches the order in which the
links appear on the Data page.
For example, if you have chosen the
Credit, Customer, Orders, and Orders Details tables from the Xtreme sample
database, the links will be processed first between the Credit/Customer tables,
then between the Customer/Orders tables, and finally between the Orders/Orders
Details tables.
Note: Different link orders
may result in different data sets returned for use in your report. As well,
link order has a significant effect on performance.