Requery transaction blocking?

CreateLotteries.java

public class CreateLotteries
{
    private static final String LOG_TAG = "CreateLotteries";
    private final SingleEntityStore<Persistable> data;

    public CreateLotteries(SingleEntityStore<Persistable> data)
    {
        this.data = data;
    }

    public List<Observable> getPopulation()
    {
        InitialLotteryProvider provider = new InitialLotteryProvider();
        List<LotteryEntityHolder> initialLotteries = provider.getEntities();

        List<Observable> observables = new LinkedList<>();
        for (LotteryEntityHolder holder : initialLotteries)
            observables.add(getObservable(holder));

        Log.v(LOG_TAG, String.format("Populated list with %d items", initialLotteries.size()));
        return observables;
    }

    private Observable<Object> getObservable(LotteryEntityHolder holder)
    {
        List<Single<? extends Persistable>> lotterySingles = new LinkedList<>();
        Single<LotteryEntity> lotterySingle = data.insert(holder.getLotteryEntity());
        lotterySingles.add(lotterySingle);

        for (LotteryNumbersEntity numberEntity : holder.getLotteryNumberEntities())
        {
            Single<LotteryNumbersEntity> lotteryNumberSingle = data.insert(numberEntity);
            lotterySingles.add(lotteryNumberSingle);
        }

        Single<?>[] elements = lotterySingles.toArray(new Single<?>[lotterySingles.size()]);
        return data.runInTransaction(elements);
    }
}

Log output

V/MainActivity: Populating database ...
V/CreateLotteries: Populated list with 12 items
V/MainActivity: Applying rx.Observable@eb7e78f
W/SQLiteConnectionPool: The connection pool for database '/data/user/0/app/databases/default' has been unable to grant a connection to thread 202 (pool-1-thread-1) with flags 0x2 for 30.000002 seconds.
                        Connections: 0 active, 1 idle, 0 available.
 W/SQLiteConnectionPool: The connection pool for database '/data/user/0/app/databases/default' has been unable to grant a connection to thread 205 (pool-1-thread-1) with flags 0x2 for 60.001003 seconds.
                        Connections: 0 active, 1 idle, 0 available.
W/SQLiteConnectionPool: The connection pool for database '/data/user/0/app/databases/default' has been unable to grant a connection to thread 205 (pool-1-thread-1) with flags 0x2 for 90.00101 seconds.
                        Connections: 0 active, 1 idle, 0 available.
W/SQLiteConnectionPool: The connection pool for database '/data/user/0/app/databases/default' has been unable to grant a connection to thread 205 (pool-1-thread-1) with flags 0x2 for 120.00101 seconds.
                        Connections: 0 active, 1 idle, 0 available.
W/SQLiteConnectionPool: The connection pool for database '/data/user/0/app/databases/default' has been unable to grant a connection to thread 205 (pool-1-thread-1) with flags 0x2 for 150.001 seconds.
                        Connections: 0 active, 1 idle, 0 available.

Lottery.java

@Table(name = "Lottery")
@Entity(name = "LotteryEntity")
public interface Lottery extends Observable, Parcelable, Persistable
{
    @Key
    @Generated
    int getID();

    @OneToMany(mappedBy = "lottery", cascade = {CascadeAction.DELETE, CascadeAction.SAVE})
    Result<LotteryNumbers> getNumbers();
}

LotteryNumbers.java

@Table(name = "LotteryNumbers")
@Entity(name = "LotteryNumbersEntity")
public interface LotteryNumbers extends Observable, Parcelable, Persistable
{
    @Key
    @Generated
    int getID();

    @ForeignKey
    @ManyToOne
    Lottery getLottery();

    int getName();
}

MainActivity.java

    private void populateDatabase()
    {
        int lotteryCount = data.count(Lottery.class).get().value();
        if (lotteryCount == 0)
        {
            Log.v(LOG_TAG, "Populating database ...");
            CreateLotteries createLotteries = new CreateLotteries(data);
            List<Observable> population = createLotteries.getPopulation();
            for (Observable observable : population)
            {
                Log.v(LOG_TAG, "Applying " + observable);
                observable.
                        observeOn(Schedulers.io()).
                        subscribe();
                Log.v(LOG_TAG, "\tDone " + observable);
            }
        }
      }