[Xapian-discuss] Re: Inexact resultset growing rapidly

[Olly Betts]

On Mon, Feb 20, 2006 at 02:17:40PM +0100, Eric Bus wrote:
> Eric Bus wrote:
> >Is this a knows issue and if so, what can I do about it?
> 
> In reply to my own message... I know of the MINHITS directive. But 
> shouldn't a one-word search always be exact? Even when Boolean queries 
> are added? Or is this only true when ONLY using a P= ?

A one-term search will always give the exact size, but boolean filters
count as terms (the only real difference between "FILTER" and "AND" is
that AND adds in weight from the right sub-query).

For flint, I'm planning to store the minimum and maximum docid indexed
by each term, which can then be used to improve the estimated number
of matches in many cases.

Cheers,
    Olly