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Date: Sat, 16 Mar 2013 10:36:36 +0800
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Subject: Re: potential query performance issue
From: Lin Ma <linlma@gmail.com>
To: java-user@lucene.apache.org, lukai1984@gmail.com
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Hi lukai, thanks for the reply. Do you mean WAND is a way to resolve this
issue? For "native support", do you mean there is no built-in (existing
ready to use externally open source) module in Lucene to implement WAND? If
so, the performance will really be bad.

regards,
Lin

On Sat, Mar 16, 2013 at 2:49 AM, lukai <lukai1984@gmail.com> wrote:

> I had implemented wand with solr/lucene. So far there is no performance
> issue.  There is no native support for this functionality, you need to
> implement it by yourself..
>
> On Fri, Mar 15, 2013 at 10:09 AM, Lin Ma <linlma@gmail.com> wrote:
>
> > Hello guys,
> >
> > Supposing I have one million documents, and each document has hundreds of
> > features. For a given query, it also has hundreds of features. I want to
> > fetch most relevant top 1000 documents by dot product related features of
> > query and documents (query/document features are in the same feature
> > space).
> >
> > I am not sure how Lucene implement internally? If we have to go through
> all
> > one million document to dot product the query, then I am concerning about
> > the performance. Appreciate if anyone could confirm (1) how Lucene works
> > internally for this use case (2) any smart ideas to make improvement for
> > query efficiency to select top 1000 documents?
> >
> > thanks in advance,
> > Lin
> >
>

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