Lookup Join

A lookup join is similar to an index join. The only difference is that the lookup join reduces the number of fields in the inner relationship and performs a sort as part of the index creation on the inner table before performing the join. A lookup join is often used for static queries and ordered dynaset-type Recordset objects.

Algorithm for Performing a Lookup Join

1. Create a sorted and indexed temporary table, selecting the necessary fields from the inner table.
   
   
2. Retrieve a value from the outer table.
   
   
3. Create a primary key for the inner table.
   
   
4. Search on the temporary table to find matches, based on the key created in step 3.
   
   
5. Check the remaining restrictions for each match.