lucene-java-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Lukas Vlcek" <lukas.vl...@gmail.com>
Subject Re: Question about highlighting returning nothing
Date Thu, 16 Aug 2007 15:06:36 GMT
Donna,

Now I understand what you are saying (seems that I had PBCAK as well ;-)

As for your last question: ...under what conditions would the highlighter
return nothing? Only if no terms matched?

I remember that I found that highlighter can return null or empty string in
different situations. I think it depends on the Analyzer used or something
like that...

BR
Lukas

On 8/16/07, Donna L Gresh <gresh@us.ibm.com> wrote:
>
> Actually I don't think I'm having trouble-- as I mentioned,
> my text is *not* stored, so to do highlighting I retrieve the
> text from the database, apply the appropriate analyzer,
> and do the highlighting. It seems to be working exactly as
> it should. My problem was that in a few cases, the document
> has been removed from the database (but not from the index)
> so when I queried the database using the identifier for the "best
> hit" from the index, nothing
> was being returned. Passing "nothing" to the highlighter
> resulted in, of course, nothing, so I was getting no highlighted
> text. Once I updated my index to be in synch with the database,
> I no longer had any empty returns from the highlighter.
>
> Donna L. Gresh
> Services Research, Mathematical Sciences Department
> IBM T.J. Watson Research Center
> (914) 945-2472
> http://www.research.ibm.com/people/g/donnagresh
> gresh@us.ibm.com
>
>
>
>
> "Lukas Vlcek" <lukas.vlcek@gmail.com>
> 08/15/2007 03:49 PM
> Please respond to
> java-user@lucene.apache.org
>
>
> To
> java-user@lucene.apache.org
> cc
>
> Subject
> Re: Question about highlighting returning nothing
>
>
>
>
>
>
> Donna,
>
> I have been investigation highlighters in Lucene recently a bit. The
> humble
> experience I've learned so far is that highlighting is completely
> different
> task from indexing/searching tandem. This simple fact is not obvious to a
> lot of people. In your particular casue it would be helpful if you can
> post
> more technical details about your system settings. Not only it is
> important
> if the field to be highlighted is stored but also it is important if you
> allow for query rewrite and what king of queries you are using (Prefix,
> Wildcard ... etc).
>
> Just my 2 cents.
>
> Lukas
>
> On 8/15/07, Donna L Gresh <gresh@us.ibm.com> wrote:
> >
> > Well, in my case the highlighting was returning nothing because of (my
> > favorite acronym) PBCAK--
> >
> > I don't store the text in the index, so I have to retrieve it separately
> > (from a database) for the highlighting, and my database was not in sync
> > with the index, so in a few cases the document in the index had been
> > deleted from the database--thus a score, but no document text.
> >
> > But I guess my original question remains; under what conditions would
> the
> > highlighter return nothing? Only if no terms matched?
> >
> > Donna
> >
>
>

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