Adding indexes

See the cqengine documentation for adding indexes and then, again, add your custom collection as backbone collection as described previously using the BarbelHistoBuilder class. Here is an example of adding an indexed collection as backbone. First define the index field.

public static final SimpleAttribute<Object, String> VERSION_ID_PK = new SimpleAttribute<Object, String>(
        "documentId") {
    public String getValue(Object object, QueryOptions queryOptions) {
        return (String) ((Bitemporal)object).getBitemporalStamp().getVersionId();
    }
};

POJOs get passed as Bitemporal proxies, thats why you can cast them to Bitemporal to get access to the Version information via the BitemporalStamp Then add the backbone collection to BarbelHisto.

BarbelHisto<T> core = BarbelHistoBuilder.barbel().withBackboneSupplier(()->{
                    IndexedCollection<T> backbone = new ConcurrentIndexedCollection<T>();
                    backbone.addIndex((Index<T>) NavigableIndex.onAttribute(VERSION_ID_PK));
                    return backbone;
                    }).build();