Building index on a map element in DPL

Question

Hi,
If I have an entity which has a map in its data elements:
@Entity
static class Person {
@PrimaryKey
String ssn;
Map<String, String> attributes;
where the map takes key value pairs for the person attributes like { ("name","Jane"), ("age", "25") }. Is there a way to build a secondary index on the name attribute, meaning that the index is on attributes.get("name")?
Thanks,
Walaa.

Answer 1

Using the DPL, the only way to do this (that I know of) is to create a many-many secondary index. Each key in the index could be a two part (name, value) key object. For example:
@Entity
static class Person {
    @PrimaryKey
    String ssn;
    @SecondryKey(relate=MANY_TO_MANY)
    Set<Atrribute> attributes;
@Persistent
static class Attribute {
    @KeyField(1)
    String name;
    @KeyField(2)
    String value;
}You can use the SecondaryIndex<Attribute, String, Person> to query Person by Attribute.
You previously said that you're using the collections API with a TupleSerialBinding, so I'm a little confused. I guess you're exploring multiple APIs?
--mark