Xapian devel - Feb 2011 - Is it possible to reset the parameters in BM25 each time a new query enters?

Hi guys,

I'm trying to improve the search results of our collection by tuning the
parameters in the BM25 weighting schema. Since our collection includes several
databases, such as for pictures, websites, etc., I would like to use different
values of the same schema to calculate the weights. Yet, rebuilding each time
after the change was done to the head file seems not an optimal approach and
costs too much time. Then I'm wondering that whether there's some way to
change the values without rebuilding. Also, I'm considering applying the
BM25 schema with different parameters values according to a specific query, or
according to the kind of databases it searches. Any suggestion is welcomed and
appreciated!

Thanks,
Peyton 
 		 	   		  
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2011/2/18 Shen Li <te_quira at hotmail.com>:
> I'm trying to improve the search results of our collection by tuning
the
> parameters in the BM25 weighting schema. Since our collection includes
> several databases, such as for pictures, websites, etc., I would like to
use
> different values of the same schema to calculate the weights. Yet,
> rebuilding each time after the change was done to the head file seems not
an
> optimal approach and costs too much time. Then I'm wondering that
whether
> there's some way to change the values without rebuilding. Also, I'm
> considering applying the BM25 schema with different parameters values
> according to a specific query, or according to the kind of databases it
> searches. Any suggestion is welcomed and appreciated!
You absolutely can set the BM25 parameters without reindexing - the
parameters are just set when setting the weight object on the enquire
object - this is all done at search time, not at index time.

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