Quantum computers can search arbitrarily large databases by a single query

This paper shows that a quantum mechanical algorithm that can query information relating to multiple items of the database can search a database for a unique item satisfying a given condition, in a single query [a query is defined as any question to the database to which the database has to return a (YES/NO answer]. A classical algorithm will be Limited to the information theoretic bound of at least log(2) N queries, which it would achieve by using a binary search.