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From "Mohammad Norouzi" <mnr...@gmail.com>
Subject Re: regarding FieldSelector
Date Sat, 15 Sep 2007 04:53:00 GMT
well, I can't see any doc() method with FieldSelector argument, perhaps this
is provided in nightly builds of Lucene, currently I am using Lucene v2.1.0
I am using org.apache.lucene.search.Searcher and new
IndexSearcher(a_directory) to instantiate an instance of it


On 9/14/07, Grant Ingersoll <grant.ingersoll@gmail.com> wrote:
>
> Searcher is a Searchable and Searchable defines the doc() method with
> FieldSelector, but I suppose we could add an abstract declaration of
> it to Searcher, since it has to be implemented on all derived
> classes anyway due to it being on the Searchable interface.
>
> So, you can either cast to a known Searcher or I suppose you can
> figure out a way to get the IndexReader.  What kind of Searcher are
> you using?
>
> -Grant
>
> On Sep 13, 2007, at 4:50 AM, Mohammad Norouzi wrote:
>
> > Thanks
> > as I saw the documents, we can only use this great field selector in
> > IndexReader.document() method the problem is I have a Searcher in
> > my result
> > set structure and when the client calls getString("a_field_name")
> > at that
> > time I invoke the searcher.doc(current_doc_id).get("a_field_name),
> > I already collected the result IDs. so in my case, I can't use
> > FieldSelector.
> >
> > Do I have to revise the way of retrieving documents in my code?
> >
> >
> >
> > On 9/12/07, Erick Erickson <erickerickson@gmail.com> wrote:
> >>
> >> Well, it depends on what "improve the search process" means
> >> in your context <G>..
> >>
> >> But I had a case similar to yours that I wrote up in the Wiki where
> >> my search times improved about 10X by using lazy loading. You
> >> might want to read that entry here...
> >>
> >> http://wiki.apache.org/lucene-java/FieldSelectorPerformance
> >>
> >> Note the peculiar characteristics of my data set, I really suspect
> >> that a 10x improvement in retrieval speed is atypical...
> >>
> >> As for when lazily-loaded fields actually get loaded, I didn't really
> >> have to explore it very fully, but a short experiment should do it
> >> for you.....
> >>
> >> Best
> >> Erick
> >>
> >> On 9/12/07, Mohammad Norouzi <mnrz57@gmail.com> wrote:
> >>>
> >>> Hi Grant,
> >>> Really thanks for your nice document about advanced Lucene. it
> >>> was very
> >>> useful for me.
> >>>
> >>> as I understand, we can set some large fields to be lazily
> >>> loading, now
> >> my
> >>> question is when it will be loaded? it make sense when we call
> >>> doc.get("field_name")
> >>> it will load from the index, Am I right?
> >>>
> >>> in my application, I've provided a result set structure to navigate
> >>> between
> >>> results and documents and provide a get(String fieldname) method
> >>> just
> >> like
> >>> java.sql.ResultSet.getString() method, and also this result set
> >> implements
> >>> HitCollector in order to collect my own ID rather than Lucene's
> >>> document
> >>> id,
> >>> so I think I can set my field ID to be loaded always and the other
> >> fields
> >>> to
> >>> be lazily loading, Does this improve the search process?
> >>>
> >>> again, thank you very much indeed.
> >>>
> >>>
> >>> On 9/12/07, Grant Ingersoll <gsingers@apache.org> wrote:
> >>>>
> >>>> Hi Mohammad,
> >>>>
> >>>> The typical use cases are:
> >>>> 1. You have several small fields used in a results display and
> >>>> one or
> >>>> two large fields (i.e. the original document) and you don't want to
> >>>> pay the cost of loading the large fields for results display
> >>>> because
> >>>> most of them won't be chosen.  When a result is chosen, the lazily
> >>>> loaded field will be retrieved.
> >>>>
> >>>> 2. You only want to load certain fields, or the first field, or you
> >>>> just want to know the size of a field.
> >>>>
> >>>> Basically, it gives you control over how fields are loaded from
> >>>> disk
> >>>> in Lucene.
> >>>>
> >>>> See my ApacheCon Europe presentation http://cnlp.org/presentations/
> >>>> slides/AdvancedLuceneEU.pdf for a few slides (towards the end) on
> >>>> FieldSelector.
> >>>>
> >>>> On Sep 12, 2007, at 5:13 AM, Mohammad Norouzi wrote:
> >>>>
> >>>>> Hi all,
> >>>>>
> >>>>> Can anyone explain what is the FieldSelector and the usage or
> >>>>> benefits of
> >>>>> this structure? I read the javadocs but I can't get for what goal
> >>>>> it is
> >>>>> provided in Lucene.
> >>>>>
> >>>>> Thanks in advance
> >>>>>
> >>>>> --
> >>>>> Regards,
> >>>>> Mohammad
> >>>>> --------------------------
> >>>>> see my blog: http://brainable.blogspot.com/
> >>>>> another in Persian: http://fekre-motefavet.blogspot.com/
> >>>>
> >>>> --------------------------
> >>>> Grant Ingersoll
> >>>> http://lucene.grantingersoll.com
> >>>>
> >>>> Lucene Helpful Hints:
> >>>> http://wiki.apache.org/lucene-java/BasicsOfPerformance
> >>>> http://wiki.apache.org/lucene-java/LuceneFAQ
> >>>>
> >>>>
> >>>>
> >>>> -------------------------------------------------------------------
> >>>> --
> >>>> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
> >>>> For additional commands, e-mail: java-user-help@lucene.apache.org
> >>>>
> >>>>
> >>>
> >>>
> >>> --
> >>> Regards,
> >>> Mohammad
> >>> --------------------------
> >>> see my blog: http://brainable.blogspot.com/
> >>> another in Persian: http://fekre-motefavet.blogspot.com/
> >>>
> >>
> >
> >
> >
> > --
> > Regards,
> > Mohammad
> > --------------------------
> > see my blog: http://brainable.blogspot.com/
> > another in Persian: http://fekre-motefavet.blogspot.com/
>
> ------------------------------------------------------
> Grant Ingersoll
> http://www.grantingersoll.com/
> http://lucene.grantingersoll.com
> http://www.paperoftheweek.com/
>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
> For additional commands, e-mail: java-user-help@lucene.apache.org
>
>


-- 
Regards,
Mohammad
--------------------------
see my blog: http://brainable.blogspot.com/
another in Persian: http://fekre-motefavet.blogspot.com/

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