lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jason Rutherglen" <jason.rutherg...@gmail.com>
Subject Re: Suggestions for drill downs
Date Fri, 05 Dec 2008 02:51:42 GMT
The field cache is completely reloaded.  LUCENE-831 solves this by merging
the field caches of the segments.  For realtime search systems, merging the
field caches is not desirable though.

On Thu, Dec 4, 2008 at 6:45 PM, John Wang <john.wang@gmail.com> wrote:

> Glad to be of help.
> Understand that FieldCache lives in a map in the static memory and is keyed
> by an IndexReader. So if your reader updates often there might be an issue
> of cleaning the map.
>
> This is a question for the Luceners, when you call IndexReader.reopen, how
> is FieldCache updated?
>
> -John
>
> On Thu, Dec 4, 2008 at 5:46 PM, Muralidharan V <muralidharan@gmail.com
> >wrote:
>
> > John,
> >
> >     Using the FieldCache worked well. Thanks!
> >
> > -Murali
> >
> > On Thu, Dec 4, 2008 at 3:10 PM, John Wang <john.wang@gmail.com> wrote:
> >
> > > Easiest way to do this is using the FieldCache. It constructs a
> > StringIndex
> > > object which gives you very fast lookup to the field value (index)
> given
> > a
> > > docid. Create a parallel count array to the lookup array for the
> > > StringIndex. Run your HitCollector thru should be fast.
> > > Loading FieldCache maybe expensive, but you do it only once when
> opening
> > > the
> > > reader.
> > >
> > > This is one way of implementing Faceted Search with Lucene but there
> are
> > > lotsa things you can do to make this faster.
> > >
> > > This is of course assuming your Brand field is indexed and not
> tokenized.
> > >
> > > One side-benefit is that if you do this, sorting on Brand would be fast
> > > because FieldCache would be already loaded.
> > >
> > > Hope this helps
> > >
> > > -John
> > >
> > >
> > > On Thu, Dec 4, 2008 at 3:02 PM, Muralidharan V <muralidharan@gmail.com
> > > >wrote:
> > >
> > > > We are evaluating lucene for a product search engine. One requirement
> > is
> > > > that we be able to suggest the top n brands(the ones with most
> products
> > > in
> > > > the result set) for a given search term to further refine the search
> > > query.
> > > > The brand is stored in a separate field and searches are performed
> > > against
> > > > product description and brand.
> > > >
> > > > One option is to use a custom HitCollector to keep track of the
> brands
> > in
> > > > the result set but that would require reading the brand field for
> each
> > > doc
> > > > that matches the search term. We think this will be an order of
> > magnitude
> > > > slower. Is there anything else that we can do?
> > > >
> > > > Thanks,
> > > > Murali
> > > >
> > >
> >
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message