Dimitri Fontaine <dimitri@2ndQuadrant.fr> writes:
> Greg Stark <gsstark@mit.edu> writes:
>> I kind of assumed the natural client for KNN-gist was the tsearch full
>> text search indexes handling sorting by relevance. For example if I
>> search for "Postgres DBA" I should find documents where those words
>> appear adjacent first and documents where the two words appear far
>> apart in the document sorted further down. Is that not on the list of
>> operators supported or planned to be supported?
> From the presentation I've seen, the typical use case is more searching
> "PostgreSQL DBA" at 100 km around a known location. Or more typical yet,
> Pizza restaurants around a known place :)
Right offhand I don't see how KNNGIST could usefully be applied to the
problem Greg is thinking about. A KNNGIST search is only going to be
fast if the target items can be found in a reasonably small part of the
index. Nearest-neighbor in a geometrically organized index qualifies,
but I don't see how Greg's problem matches the structure of a tsearch
index.
regards, tom lane