-Re: It's hard to google on _val_
Yonik Seeley 2012-04-15, 16:14
On Sun, Apr 15, 2012 at 11:34 AM, Benson Margulies
<[EMAIL PROTECTED]> wrote:
> So, I've been experimenting to learn how the _val_ participates in scores.
> It seems to me that http://wiki.apache.org/solr/FunctionQuery should
> explain the *effect* of including an _val_ term in an ordinary query,
> starting with a constant.
It's simply added to the score as any other clause in a boolean query would be.
> Positive values of _val_ did lead to
> positive increments in the score, but clearly not by simple addition.
That's just because Lucene "normalizes" scores. By default, this is
really just multiplying scores by a magic constant (that by default is
the inverse of the sum of squared weights) and doesn't change relative
orderings of docs. If you add debugQuery=true and look at the scoring
explanations, you'll see that queryNorm component.
If you want to go down the rabbit hole on trunk, see
lucenerevolution.com - Lucene/Solr Open Source Search Conference.
Boston May 7-10