I'm calculating distance between probability vectors, e.g. topics that a document belongs to and the topics of an ad. The distance function is already a C function. Topics are float8[150]. Distance is calculated against all documents in the database so it's arable scan. Sent from my comfortable recliner On 30/04/2011, at 19:04, Pierre C <lists@xxxxxxxxxx> wrote: > > If you want to search by geographical coordinates, you could use a gist index which can optimize that sort of things (like retrieving all rows which fit in a box). -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
