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Posted to solr-user@lucene.apache.org by Paolo Castagna <ca...@googlemail.com> on 2010/10/12 10:15:35 UTC

Faceting and omitNorms=true

Hi,
I am not completely sure on what's the recommended setting for fields
used for faceting regarding omitNorms and potitionIncrementGap.

Should I used omitNorms="true"?

What about positionIncrementGap?

At the moment I have this in my schema.xml:

   <dynamicField name="*_facet" type="keyword" indexed="true" 
stored="false" multiValued="true" />
   <fieldType name="keyword" class="solr.TextField">
    <analyzer class="org.apache.lucene.analysis.KeywordAnalyzer"/>
   </fieldType>

And I was thinking to change to:

   <dynamicField name="*_facet" type="keyword" indexed="true" 
stored="false" multiValued="true" omitNorms="true" 
positionIncrementGap="100" />

There is documentation, but I did not find a definite answer for
omitNorms in relation to faceting.

  "faceting: indexed='true'"
   -- http://wiki.apache.org/solr/FieldOptionsByUseCase

  "Only full-text fields or fields that need an index-time boost need
   norms."
   -- 
http://svn.apache.org/repos/asf/lucene/dev/trunk/solr/example/solr/conf/schema.xml


Thank you,
Paolo

Re: Faceting and omitNorms=true

Posted by Markus Jelsma <ma...@openindex.io>.
You can safely set it to 0 (default) for solr.Textfield types that you don't do 
sloppy phrase queries on.

From the schema.xml comments:
> The optional positionIncrementGap puts space between multiple fields
> of this type on the same document, with the purpose of preventing
> false phrase matching across fields.

Sloppyness can extend the boundary of a phrase, using a positionIncremenGap 
(higher than your slop)  can negate the sloppyness for multiple fields in the 
same document.


On Tuesday, October 12, 2010 10:56:18 am Paolo Castagna wrote:
> Thank you Markus for your quick reply.
> Do you have a recommendation|suggestion about positionIncrementGap?
> 
> Paolo
> 
> Markus Jelsma wrote:
> > You can omit norms in field that you only facet on. The matrix only lists
> > mandatory values for those parameters.
> > 
> > On Tuesday, October 12, 2010 10:15:35 am Paolo Castagna wrote:
> >> Hi,
> >> I am not completely sure on what's the recommended setting for fields
> >> used for faceting regarding omitNorms and potitionIncrementGap.
> >> 
> >> Should I used omitNorms="true"?
> >> 
> >> What about positionIncrementGap?
> >> 
> >> At the moment I have this in my schema.xml:
> >>    <dynamicField name="*_facet" type="keyword" indexed="true"
> >> 
> >> stored="false" multiValued="true" />
> >> 
> >>    <fieldType name="keyword" class="solr.TextField">
> >>    
> >>     <analyzer class="org.apache.lucene.analysis.KeywordAnalyzer"/>
> >>    
> >>    </fieldType>
> >> 
> >> And I was thinking to change to:
> >>    <dynamicField name="*_facet" type="keyword" indexed="true"
> >> 
> >> stored="false" multiValued="true" omitNorms="true"
> >> positionIncrementGap="100" />
> >> 
> >> There is documentation, but I did not find a definite answer for
> >> omitNorms in relation to faceting.
> >> 
> >>   "faceting: indexed='true'"
> >>   
> >>    -- http://wiki.apache.org/solr/FieldOptionsByUseCase
> >>   
> >>   "Only full-text fields or fields that need an index-time boost need
> >>   
> >>    norms."
> >> 
> >> http://svn.apache.org/repos/asf/lucene/dev/trunk/solr/example/solr/conf/
> >> sch ema.xml
> >> 
> >> 
> >> Thank you,
> >> Paolo

-- 
Markus Jelsma - CTO - Openindex
http://www.linkedin.com/in/markus17
050-8536600 / 06-50258350

Re: Faceting and omitNorms=true

Posted by Paolo Castagna <ca...@googlemail.com>.
Thank you Markus for your quick reply.
Do you have a recommendation|suggestion about positionIncrementGap?

Paolo


Markus Jelsma wrote:
> You can omit norms in field that you only facet on. The matrix only lists 
> mandatory values for those parameters.
> 
> On Tuesday, October 12, 2010 10:15:35 am Paolo Castagna wrote:
>> Hi,
>> I am not completely sure on what's the recommended setting for fields
>> used for faceting regarding omitNorms and potitionIncrementGap.
>>
>> Should I used omitNorms="true"?
>>
>> What about positionIncrementGap?
>>
>> At the moment I have this in my schema.xml:
>>
>>    <dynamicField name="*_facet" type="keyword" indexed="true"
>> stored="false" multiValued="true" />
>>    <fieldType name="keyword" class="solr.TextField">
>>     <analyzer class="org.apache.lucene.analysis.KeywordAnalyzer"/>
>>    </fieldType>
>>
>> And I was thinking to change to:
>>
>>    <dynamicField name="*_facet" type="keyword" indexed="true"
>> stored="false" multiValued="true" omitNorms="true"
>> positionIncrementGap="100" />
>>
>> There is documentation, but I did not find a definite answer for
>> omitNorms in relation to faceting.
>>
>>   "faceting: indexed='true'"
>>    -- http://wiki.apache.org/solr/FieldOptionsByUseCase
>>
>>   "Only full-text fields or fields that need an index-time boost need
>>    norms."
>> http://svn.apache.org/repos/asf/lucene/dev/trunk/solr/example/solr/conf/sch
>> ema.xml
>>
>>
>> Thank you,
>> Paolo
> 

Re: Faceting and omitNorms=true

Posted by Markus Jelsma <ma...@openindex.io>.
You can omit norms in field that you only facet on. The matrix only lists 
mandatory values for those parameters.

On Tuesday, October 12, 2010 10:15:35 am Paolo Castagna wrote:
> Hi,
> I am not completely sure on what's the recommended setting for fields
> used for faceting regarding omitNorms and potitionIncrementGap.
> 
> Should I used omitNorms="true"?
> 
> What about positionIncrementGap?
> 
> At the moment I have this in my schema.xml:
> 
>    <dynamicField name="*_facet" type="keyword" indexed="true"
> stored="false" multiValued="true" />
>    <fieldType name="keyword" class="solr.TextField">
>     <analyzer class="org.apache.lucene.analysis.KeywordAnalyzer"/>
>    </fieldType>
> 
> And I was thinking to change to:
> 
>    <dynamicField name="*_facet" type="keyword" indexed="true"
> stored="false" multiValued="true" omitNorms="true"
> positionIncrementGap="100" />
> 
> There is documentation, but I did not find a definite answer for
> omitNorms in relation to faceting.
> 
>   "faceting: indexed='true'"
>    -- http://wiki.apache.org/solr/FieldOptionsByUseCase
> 
>   "Only full-text fields or fields that need an index-time boost need
>    norms."
> http://svn.apache.org/repos/asf/lucene/dev/trunk/solr/example/solr/conf/sch
> ema.xml
> 
> 
> Thank you,
> Paolo

-- 
Markus Jelsma - CTO - Openindex
http://www.linkedin.com/in/markus17
050-8536600 / 06-50258350