Return index only fields in Apache Ignite Index Query

Question

I am trying to run Index Query on Sample code and able to fetch records. Ignite docs say it is possible to configure the value type returned in response(key, value, indexed fields) but I dont see any such fields in Index Query class.(Refer Phase4 in doc below)

"User will specify a flag in IndexQuery: KeyOnly, ValueOnly, IndexFieldsOnly. Result for queries are:

• KeyOnly: QueryCursor<Cache.Entry<K, V>> where value is always NULL;
• ValueOnly: QueryCursor<Cache.Entry<K, V>> where key is always NULL;
• IndexFieldsOnly: QueryCursor<Cache.Entry<K, V>> where key is always NULL, value is an object with NULL in non-indexed fields. "

https://cwiki.apache.org/confluence/display/IGNITE/IEP-71%3A+Public+API+for+secondary+index+search

POJOs:

public class Department {
    @QuerySqlField(orderedGroups = {@QuerySqlField.Group(name = "dept_idx", order = 0)})
    private final int deptId;
    @QuerySqlField
    @AffinityKeyMapped
    private final String deptName;
    @QuerySqlField
    private final String hod;
}
public class DepartmentKey {
    private final int deptId;
}

Query code:

IndexQueryCriterion endKeyFilter = lte("deptId", 4);
        IndexQuery<DepartmentKey, Department> indexQuery = new IndexQuery<>(Department.class, "DEPT_IDX");
        indexQuery.setCriteria(gte("deptId", 2), endKeyFilter);
        Iterator<Cache.Entry<DepartmentKey, Department>> it = cache.query(indexQuery.setPageSize(100)).iterator();

Answer 1

IndexQuery is an experimental API that was introduced in Ignite 2.12.0, and currently, only the first two phases have been implemented, due to that it has limited functionality.

You can find a discussion regarding this feature development on the dev list here.