class UnionDB extends CompositeDB implements Union {

	@Override
	public DataTypeComponent getComponent(int ordinal) {
		lock.acquire();
		try {
			checkIsValid();
			if (ordinal < 0 || ordinal >= components.size()) {
				return null;
			}
			return components.get(ordinal);
		}
		finally {
			lock.release();
		}
	}

	public  UnionDB(DataTypeManagerDB dataMgr, DBObjectCache<DataTypeDB> cache,
			CompositeDBAdapter compositeAdapter, ComponentDBAdapter componentAdapter,
			Record record);

}