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Posted to java-user@lucene.apache.org by blazingwolf7 <bl...@gmail.com> on 2008/08/18 04:59:48 UTC
Index of Lucene
Hi,
I am currently using Lucene for indexing. After a index a file, I will use
LUKE to open it and check the index. And there is 1 part that I am curious
about. In Luke, under the Document tab, I randomly select a document and
display it. At the bottom will be 4 columns, Field, ITSVopLBC, Norm and
String Value.
I am wondering, what is Norm for? And where is it created during indexing
time? Which method calculates it?
Could anyone advise me on this? Thanks for the help
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Re: Index of Lucene
Posted by Doron Cohen <cd...@gmail.com>.
On Mon, Aug 18, 2008 at 7:28 AM, blazingwolf7 <bl...@gmail.com>wrote:
>
> Thanks for the info. But do you know where this is actually perform in
> Lucene? I mean the method involved, that will calculate the value before
> storing it into the index. I track it to one method known as lengthNorm()
> in
> DefaultSimilarity.java, but the value is different from what is stored in
> the index
>
I believe the answer to your question is in this paragraph:
http://lucene.apache.org/java/2_3_2/scoring.html#Score%20Boosting
Re: Index of Lucene
Posted by blazingwolf7 <bl...@gmail.com>.
Thanks for the info. But do you know where this is actually perform in
Lucene? I mean the method involved, that will calculate the value before
storing it into the index. I track it to one method known as lengthNorm() in
DefaultSimilarity.java, but the value is different from what is stored in
the index
Doron Cohen-2 wrote:
>
> Norms information comes mainly from lengths of documents - allowing the
> search time scoring to take into account the effect of document lengths
> (actually
> field length within a document). In practice, norms stored within the
> index
> may include
> other information, such as index time boosts - for a document, for a
> field.
> A single
> byte is stored for each field, - so for this the actual value is
> compressed.
> At search
> time, norms are loaded into memory, and so consume 1 byte for each
> document.
> It is possible to disable norms for a field while indexing. This is
> explained
> better in the javadoc for Similarity, and here:
> http://lucene.apache.org/java/2_3_2/scoring.html
>
> Doron
>
> On Mon, Aug 18, 2008 at 5:59 AM, blazingwolf7
> <bl...@gmail.com>wrote:
>
>>
>> Hi,
>>
>> I am currently using Lucene for indexing. After a index a file, I will
>> use
>> LUKE to open it and check the index. And there is 1 part that I am
>> curious
>> about. In Luke, under the Document tab, I randomly select a document and
>> display it. At the bottom will be 4 columns, Field, ITSVopLBC, Norm and
>> String Value.
>>
>> I am wondering, what is Norm for? And where is it created during indexing
>> time? Which method calculates it?
>>
>> Could anyone advise me on this? Thanks for the help
>> --
>> View this message in context:
>> http://www.nabble.com/Index-of-Lucene-tp19025490p19025490.html
>> Sent from the Lucene - Java Users mailing list archive at Nabble.com.
>>
>>
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
>> For additional commands, e-mail: java-user-help@lucene.apache.org
>>
>>
>
>
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Re: Index of Lucene
Posted by Doron Cohen <cd...@gmail.com>.
Norms information comes mainly from lengths of documents - allowing the
search time scoring to take into account the effect of document lengths
(actually
field length within a document). In practice, norms stored within the index
may include
other information, such as index time boosts - for a document, for a field.
A single
byte is stored for each field, - so for this the actual value is compressed.
At search
time, norms are loaded into memory, and so consume 1 byte for each document.
It is possible to disable norms for a field while indexing. This is
explained
better in the javadoc for Similarity, and here:
http://lucene.apache.org/java/2_3_2/scoring.html
Doron
On Mon, Aug 18, 2008 at 5:59 AM, blazingwolf7 <bl...@gmail.com>wrote:
>
> Hi,
>
> I am currently using Lucene for indexing. After a index a file, I will use
> LUKE to open it and check the index. And there is 1 part that I am curious
> about. In Luke, under the Document tab, I randomly select a document and
> display it. At the bottom will be 4 columns, Field, ITSVopLBC, Norm and
> String Value.
>
> I am wondering, what is Norm for? And where is it created during indexing
> time? Which method calculates it?
>
> Could anyone advise me on this? Thanks for the help
> --
> View this message in context:
> http://www.nabble.com/Index-of-Lucene-tp19025490p19025490.html
> Sent from the Lucene - Java Users mailing list archive at Nabble.com.
>
>
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> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
> For additional commands, e-mail: java-user-help@lucene.apache.org
>
>