[Xapian-discuss] Faster "sort by value"

[Olly Betts]

I noticed while working on something else that "sort by value" was
fetching the values in a stupid way such that the document data was also
being fetched every time a value was!  Assuming I'm right, this patch
should give a substantial speed boost for anyone using "sort by value":

http://www.oligarchy.co.uk/xapian/patches/xapian-faster-"sort by value".patch

I don't have time right now to set up a test database and time it, so if
you have a large database and use "sort by value", please apply the patch
and try timing some searches with and without it.

The patch changes "sort by value" to use the same code as "collapse on a
value" and "matchdecider" do and the test suite passes with it applied,
so I'd say it's a very safe patch suitable for use on a production system.

Cheers,
    Olly