[Xapian-devel] How the matcher knows when to prune and decay

[Matt Chaput]

> On Wed, Mar 03, 2010 at 06:33:10PM -0500, Matt Chaput wrote:
>> But how can the leaf object reading the posting list know its maximum  
>> future score?
> 
> It asks its weight object (or just knows if it is a PostingSource).

I'm asking about the on-disk structures that allow a posting source to "just know". If the postings are written to disk in document order, and the posting reader object is reading through them linearly, then I would naively assume it can't know what weights are coming up in the list. So presumably there's some clever structure in the storage format the allows this. If you see what I mean.

Thanks,

Matt