Load balancing in a parallel database system is performed using multi-reordering, in which a sequence of multiple processors (two, three, or more) that have small average load (for example, the smallest of any such sequence) is selected to participate in load balancing. In the case of three adjacent low-load processors, the load of all three is evenly distributed over two of them, and the remaining processor becomes a free processor. The free processor is moved adjacent to a high-load processor, the load of which is then shared with the free processor. Data is moved in a “transaction” so that the view of data is always consistent. The database continues to service requests from a former location while data undergoes a transfer.