Some Approaches to Best-Match File Searching
The problem of searching the set of keys in
a file to find a key which is closest to a given 
query key is discussed.  After "closest," in terms of
a metric on the the key space, is suitably defined, 
three file structures are presented together with their
corresponding search algorithms, which are intended 
to reduce the number of comparisons required to achieve
the desired result. These methods are derived 
using certain inequalities satisfied by metrics and by
graph-theoretic concepts.  Some empirical results 
are presented which compare the efficiency of the methods.
CACM April, 1973
Burkhard, W. A.
Keller, R. M.
