Index Link Analysis

Index link analysis generates the links between the tables in the data dictionary.

1. On the Database Creation/Changes menu, select option 5 - Makelink/Setlink:
   

   DP4 performs an index analysis on your database structure in this order:

   • Tables are checked for missing and duplicate keys.
   • The field positions within tables are set and data independence records created.
   • Old index records are marked for deletion.
   • Index records are created for the primary index of each table.
   • Index records are created for secondary indexing. Secondary indexes are created for fields that are the primary keys of higher tables. For example, the CUSTOMER_NUMBER, which is the primary key of the CUSTOMER table, is a secondary key in the ORDER_HEADER table. This allows ORDER_HEADER records to be indexed in customer sequence.
   • Index records are created for indirect joins. These are links between indirectly related tables: child to grand parent, child to great grandparent and so on.
   • Obsolete index records are removed.
   MAKELINK creates a log file which will list any new links that have been created or old links that have been removed.

2. When the Index Analysis is complete MAKEDB will display a menu allowing you to view the MAKELINK log, run the Index Scrutiny program, SETLINK, or return to the MAKEDB main menu. You should always run SETLINK when you first create a database, or whenever you have added new tables or indexes later on, or have modified the keys of an existing table.