When you use a composite key, the number of search keys increases. The increased number of keys in a composite key results in higher specificity and selectivity that narrows down search results to a fewer and more relevant records. As a result, the search handles less data and results in improved performance.

Consider a scenario where you specify the

Organization_Name

field to create an index without using a composite key. The search results might include a large number of records that match the search key. In this scenario, if you want to refine the search based on the

Address_Part1

field, the match request needs to compare the

Organization_Name

and

Address_Part1

fields in all of these records. This approach might take longer.

Consider another scenario where you combine the

Organization_Name

and

Address_Part1

fields to generate the composite key. In this case, the search is initially limited to the records that match the values in the

Organization_Name

and

Address_Part1

fields. This approach improves the search performance.

When you use a composite key, the search results don't include fields that contain empty values. To include fields with empty values in search results, use

N3KEYWORDS

along with a composite key. For example, to retrieve records that have fields with empty values, you can use keywords such as

INSERTNULLCLOSINGRANGE

and

INSERTNULLCLOSINGKEY

with a composite key.

For more information about these keywords, see

Additional keywords and controls for composite keys

in the

Informatica SSA-Name3 API Reference Guide

.