> encode spatial proximity. Is there an API (backend C-level is fine) to
> access a GIST index?
The best way is to extend existing interface to GiST to support KNN-search. But
you can see how to get access to index structure from module in gevel module
(http://www.sigaev.ru/cvsweb/cvsweb.cgi/gevel/). GiST-related functions in this
module is invented to help to developers, not for production use, so they
acquire exclusive lock on index.
--
Teodor Sigaev E-mail: teodor@sigaev.ru
WWW: http://www.sigaev.ru/