[Xapian-discuss] Rqt for Features 2

[Olly Betts]

On Wed, Aug 11, 2004 at 07:41:33PM -0400, Eric B. Ridge wrote:
> On Aug 11, 2004, at 5:43 PM, Olly Betts wrote:
> >On Wed, Aug 11, 2004 at 05:25:01PM -0400, Eric B. Ridge wrote:
> >>What about (at least right-truncation) wildcard support in the
> >>QueryParser?
> >
> >It wouldn't be very hard to add, especially if you could post the code
> >you use.
> 
> it amounts to a TermIterator::skip_to() and a while() loop.  :)

I know, but a working implementation would still save me time.

> I'm going on vacation the first week of September (yay!).  I've got a 
> long flight to my destination.  I can take a stab at implementing 
> something at least equivalent to the basic matching I've done in java, 
> and then we can tweak it from there...

That would save me more time!

> Another thing I'd like to see is range searching.  Date, number, and 
> character ranges.  This could be done as another QueryParser thing 
> (syntax like "1:5" or "1...5" maybe).

Google uses the syntax 1..5 :

http://www.google.com/help/refinesearch.html#numrange

> What do you think about this?

Seems reasonable, especially if we allow people to control the features
they want to support.

> I seem to remember reading/seeing that Omega does 
> something special for date-range searches.

Yes, we generate terms for each date, and also the month and year.  Then
we can build an OR query of reasonable size for even a long date range -
whole years in the range are expressed by a single term, as are whole
months in partial years at the ends of the range.  Any partial months are
expressed by OR-ing individual date terms together.

We could do something similar to improve the speed of large number
ranges.

Cheers,
    Olly