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From Chuck Williams <ch...@manawiz.com>
Subject Re: Combining search steps without re-searching
Date Mon, 28 Aug 2006 18:43:47 GMT
I presume your search steps are anded, as in typical drill-downs?

>From  a Lucene standpoint, each sequence of steps is a BooleanQuery of
required clauses, one for each step.  To add a step, you extend the
BooleanQuery with a new clause.  To not re-evaluate the full query,
you'd need some query that regenerated the results of the prior step
more efficiently than BooleanQuery.  For example, if you happened to
generate the entire result set for each step, presumably not feasible,
then the results might be cached for regeneration.  Assuming you cannot
generate the entire result set, it's not obvious to me how having
partially generated S1 and ... Sn-1 will help you generate S1 and ... Sn
any faster.

You will already get the the benefit of OS caching with Lucene as it
stands.  You might find further caching extension to the query types you
use to be a performance gain that achieves what you want.  You might
also consider some kind of query optimization by extending the rewrite()
methods.

Chuck


Fernando Mato Mira wrote on 08/28/2006 12:21 AM:
> Hello,
>
>  We think we would have a problem if we try to use lucene because we
> do search combinations which might have hundreds of steps, so creating
> a combined query and executing again each time might be a problem.
>  What would entail overhauling Lucene to do search combinations by
> taking advantage of the results already generated?
>
> Thanks
>
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