Re: KNNGiST for knn-search
Teodor Sigaev <teodor@sigaev.ru>
From: Teodor Sigaev <teodor@sigaev.ru>
To: Simon Riggs <simon@2ndQuadrant.com>
Cc: Pgsql Hackers <pgsql-hackers@postgresql.org>
Date: 2009-11-26T16:37:13Z
Lists: pgsql-hackers
> explain select col1 from s order by abs(col1 - 5) limit 10;
>
> is the one-dimensional equivalent of the type of query you're proposing
Exactly, it's already done in next version of patch :)
> and that doesn't work either until you put an index on abs(col1 - 5),
> then it just works, but only for k = 5.
BTW, it's possible to add this feature to plain btree by changing traversal
algorithm, but I'm fill enough power to do it.
--
Teodor Sigaev E-mail: teodor@sigaev.ru
WWW: http://www.sigaev.ru/