A method of adaptively evaluating a top-k query involves (1204) forming a servers having respective server queues storing candidate answers, processing (1322) the candidate answers, and (1232) providing a top-k set as a query evaluation. Processing includes (1402) adaptively choosing a winning server to whose queue a current candidate answer should be sent; (1404) sending the current candidate answer to the winning server's queue; (1334) adaptively choosing a next candidate answer to process from the winning server's queue; (1336) computing a join between the current candidate answer and next candidate answers at the winning server, so as to produce a new current candidate answer; and (1338) updating the top-k set with the new current candidate answer only if a score of the new current candidate answer exceeds a score of a top-k answer in a top-k set. A method of calculating scores for candidate answers is also provided.