Indexes
All record finding in Data Dictionaries occurs using indexes. Indexes are used to quickly find individual records and to navigate up or down a table in a specified order.
To be used properly by Data Dictionaries, each index entry must be unique. In other words, the segments used to create an index must not allow duplicates. Uniqueness is usually assured by appending the primary key field(s) as the last segment(s) of the index.
Indexes are defined within the Studio's Table Editor and assigned an index number. That number is used in Data Dictionaries and in your code to determine which index to use.