[Xapian-discuss] 100% relevant

[Olly Betts]

On Tue, Aug 17, 2004 at 08:31:35AM +0100, Francis Irving wrote:
> Every query seems to be returning 100% relevant for every result, all
> the way down to the last one returned.
> 
> That is if I search for something like "treatment OR centre", it
> returns 16758 responses, all with the same relevancy, being 100%.  And
> get_weight returns 0 as well.
>
> There are only 581 documents containing "treatment AND centre", so
> surely some of those should have a higher relevancy than others?

Definitely.  It sounds like the query is being run with boolean weights.

> This is with Xapian 0.8.1, using either the PHP or the Perl bindings.
> It's for TheyWorkForYou.com, but my examples above are from a command
> line query tool I have for testing (the site itself always does AND).
> 
> We noticed the problem because people found they weren't getting
> relevant search results.  Everything appears to come vaguely in date
> order because of the order stuff is loaded into the database with, but
> only vaguely and it's quite confusing - you can certainly try that for
> yourself searching on the live site.

With boolean weighting documents will be ordered with lower docids
first.

> I'm pretty sure I've broken something.  Any suggestions how I can find
> out what?  Thanks very much for any help.

Probably the first thing to try is "make check" on the xapian-core
tarball.  If that fails, it'll give us somewhere to look.  If it
doesn't, then the xapian library is probably OK - if get_weight()
always returned zero, several tests would fail.

Cheers,
    Olly