[Xapian-discuss] Question about synonyms and relevancy results.

[Olly Betts]

On Thu, Jan 03, 2008 at 04:18:15PM +0000, James Aylett wrote:
> I suppose in theory we could have an operator that acts as OP_OR but
> returns the highest BM25 termweight or something (so the synonyms act
> as an expansion inside the query, rather than outside as at the
> moment), but I have no idea if that would be generally useful, or
> practical with respect to any of the optimisations we do.

Richard is working on a new OP_SYNONYM operator on SVN branch opsynonym:

http://svn.xapian.org/branches/opsynonym/

See also:

http://www.xapian.org/cgi-bin/bugzilla/show_bug.cgi?id=50

OP_SYNONYM is like OP_OR except that the statistics are calculated as if
all the sub-postlists were postings of the same term (some
approximations are required to achieve this without the computations
being prohibitively expensive).

All being well this will be in 1.1.0.  

Cheers,
    Olly