When using PC (not SQL or ODBC) databases,
the link field in the lookup database needs to be indexed in order to create a
valid link. You cannot link the tables in a single report when two tables
contain related data yet neither is indexed on the field which you want to use
as a link field, or when the primary table is indexed but the lookup table is
not. You must use subreports if you want to coordinate the data in both tables.
Note: It is important to note
that linking unindexed tables or linking from an indexed primary table to an
unindexed lookup table may cause inefficient reporting. If your data set is
large, this kind of report will take considerable time to run. Use this
technique only if you do not have other options.