[Xapian-discuss] Rqt for Features 2

[Olly Betts]

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 could prove expensive on large databases so I wonder if it should be
optional or at least allow the minimum stem length to be specified (or
perhaps the maximum number of terms to allow expansion to).  It would
be good to allow control of other features too - some people may not
want to support boolean operators for example.

> What are the odds of getting something like this hooked directly into 
> Xapian?  Either the QueryParser or the Query/Matcher?

I don't think pushing it into the matcher would allow a more efficient
implementation, so I guess it should probably just go in the QueryParser,
at least for now.

> Also, quite frequently I need to simply find "all documents that do 
> *not* contain term X".  I haven't been able to successfully construct a 
> Query to make this happen.  If I'm remembering the API docs correctly, 
> the null ctor for Query "matches no documents".  Would be useful to 
> have a form that matches *all* documents.

There isn't one currently.  The plan is that the empty term should index
all documents to allow things like this, but my patch to do this hasn't
made much progress recently I'm afraid...

Cheers,
    Olly