[Xapian-discuss] Matches estimate varies with sorting method

[Fabrice Colin]

On 10/25/07, Olly Betts <olly at survex.com> wrote:
> On Mon, Oct 22, 2007 at 07:09:06PM +0800, Fabrice Colin wrote:
> > When sorting by relevance, all three get_matches methods return 10.
>
> The problem here is for the case where checkatleast is set, and we're
> sorting by relevance with forward ordering by docid, and the query is
> pure boolean.  The optimisation to terminate processing fires before
> the checkatleast requirement is satisfied, and adjustments made to the
> estimated and max statistics based on checkatleast then make the
> statistics wrong in the way we see.
>
> Can you confirm this patch fixes it for you:
>
> http://oligarchy.co.uk/xapian/patches/xapian-fix-checkatleast-boolean-sortforward.patch
>
Okay, I can confirm this patch fixes the problem I reported.
Thanks for that.

Fabrice