[Xapian-discuss] Current status of reverse sorting and unstemmed searching on stemmed database

[Olly Betts]

On Thu, Mar 09, 2006 at 11:27:31PM +0100, Eric Bus wrote:
> I remember a conversation from about a year ago about reverse sorting
> with Omega. Is this feature still on the TODO list?

It was implemented some time ago, and released in 0.9.3.  See the
SORTREVERSE cgi parameter.

> Second question. Is it possible to disable stemming at query time when
> the database has been indexed with a certain stemming algorithm? Some of
> our users don't like the stemming feature, others do. So I would like to
> disable the stemming for certain queries. Adding $set{stemming,none} to
> the Omega template resulted in no results, but maybe it's not possible
> at all?

Currently Omega stores the terms in stemmed form, so they aren't there
to search for unstemmed.  Capitalised terms are also stored unstemmed
with an R prefix, but that doesn't allow a general "unstemmed search".

The R-prefix approach isn't ideal, and I have some thoughts on a better
strategy, but I need to try them out and see how they actually perform.

Anyway, right now your simplest solution is probably to build a second
index without stemming to provide the "unstemmed search".

Cheers,
    Olly