1. A parallel computer system comprising: a plurality of nodes coupled together that each have clocks that are independent of each other, wherein each of the plurality of nodes includes a portion of a database that is referenced by a specified query that includes a timestamp parameter; a time server coupled to the plurality of nodes that provides a reference time; and a timestamp synchronization mechanism in each of the plurality of nodes that accesses the time server and assures values for the timestamp parameter for the specified query are identical in each of the plurality of nodes.