[Xapian-devel] Last minute feature for 1.0.0

[Olly Betts]

On Fri, May 04, 2007 at 03:38:14PM +0100, Richard Boulton wrote:
> Olly Betts wrote:
> >I understand your motivation for wanting this in 1.0.0, but I'm afraid
> >the time really has passed for crowbarring random new features into the
> >release.  I've already said "not until after 1.0.0" to patches submitted
> >weeks or months ago!
> 
> Fair enough - I just thought I'd ask, since the feature requires an 
> incompatible database change.

I didn't look at the patch itself, but presumably it just adds extra
information to the end of the metadata record, so this change can at
least quietly upgrade existing flint databases?

Flint databases without the metainfo would be the same before and after
anyway, and an application relying on this feature would need to require
a particular Xapian version anyway.

> I don't _think_ there's a bug here, but I understand your worries.  I 
> think I'll pull the patch back out and merge it with the patch in bug 
> #143 for later application.

I don't actually think there is either, but I worry there might be.

Removing the unused transaction method declarations is certainly fine
(but they're non-virtual, so I doubt it actually makes any different to
the generated code).

> >Also, we now always retrieve and parse the metainfo record, even if we
> >never use the information - if you're using a weighting scheme which
> >ignores document length, I think that means that the first search on a
> >cold database will now be slower.  At least that's not the default
> >for BM25Weight.
> 
> On the other hand, we only retrieve and parse the information once now, 
> rather than every time we calculate the average document length.

Yes, that is certainly an improvement (though I think the layers
generally don't reread such values).

Cheers,
    Olly