public DocumentDatabase getDocumentDatabase(Query query) {
        if (query.getModel().getRestrict().size() == 1) {
            String docTypeName = (String)query.getModel().getRestrict().toArray()[0];
            DocumentDatabase db = documentDbs.get(docTypeName);
            if (db != null) {
                return db;
            }
        }
        return defaultDocumentDb;
    }
Returns whether we need to send the query when fetching summaries.
This is necessary if the query requests summary features or dynamic snippeting.
container-search/src/main/java/com/yahoo/prelude/fastsearch/VespaBackend.java