*All* columns you use in your query (SELECT or WHERE clause) must be within the index, of course this might be less than all columns defined in the SI.
Additonaly details are in the Database Design manual
Chapter 10: Secondary Indexes
NUSIs and Query Covering
*All* columns you use in your query (SELECT or WHERE clause) must be within the index, of course this might be less than all columns defined in the SI.
Additonaly details are in the Database Design manual
Chapter 10: Secondary Indexes
NUSIs and Query Covering
Dieter