hollow/src/main/java/com/netflix/hollow/core/index/key/HollowPrimaryKeyValueDeriver.java
public Object[] getRecordKey(int ordinal) {
        Object[] results = new Object[fieldPathIndexes.length];

        for (int i = 0; i < fieldPathIndexes.length; i++) {
            results[i] = readValue(ordinal, i);
        }
        return results;
    }
public Object[] getRecordKey(int ordinal) {
        Object[] results = new Object[fieldPathIndexes.length];

        for (int i = 0; i < fieldPathIndexes.length; i++) {
            results[i] = readValue(ordinal, i);
        }
        return results;
    }
Retrieve the primary key value for the specified ordinal.

@param ordinal the oridinal
@return the primary keys