A little help with indexing joined words
Hi I am hoping someone can point me in the right direction with regards to indexing words that are concatenated together to make other words or product names. We have indexed a product database and have come across some search terms where zero results are returned. There are products in the index with 'Borderlands xxx xxx', 'Dragonfly xx xxx' in the title. Searches for 'Borderland' or 'Border Land' and 'Dragon Fly' return zero results respectively. Where do I look to resolve this? The product name field is indexed using a text field type. Thanks in advance Andrew
Re: A little help with indexing joined words
We have indexed a product database and have come across some search terms where zero results are returned. There are products in the index with 'Borderlands xxx xxx', 'Dragonfly xx xxx' in the title. Searches for 'Borderland' or 'Border Land' and 'Dragon Fly' return zero results respectively. Borderland should have worked for a regular text field. For all other desired matches you can use EdgeNGramTokenizerFactory. Cheers Avlesh On Mon, Oct 5, 2009 at 7:51 PM, Andrew McCombe eupe...@gmail.com wrote: Hi I am hoping someone can point me in the right direction with regards to indexing words that are concatenated together to make other words or product names. We have indexed a product database and have come across some search terms where zero results are returned. There are products in the index with 'Borderlands xxx xxx', 'Dragonfly xx xxx' in the title. Searches for 'Borderland' or 'Border Land' and 'Dragon Fly' return zero results respectively. Where do I look to resolve this? The product name field is indexed using a text field type. Thanks in advance Andrew
Re: A little help with indexing joined words
Using synonyms might be a better solution because the use of EdgeNGramTokenizerFactory has the potential of creating a large number of token which will artificially increase the number of tokens in the index which in turn will affect the IDF score. A query for borderland should have returned results though. It is difficult to troubleshoot why it didn't without knowing what query you used, and what kind of analysis is taking place. Have you tried using the analysis page on the admin section to see what tokens gets generated for 'Borderlands'? Christian On 10/05/2009 11:01 AM, Avlesh Singh wrote: We have indexed a product database and have come across some search terms where zero results are returned. There are products in the index with 'Borderlands xxx xxx', 'Dragonfly xx xxx' in the title. Searches for 'Borderland' or 'Border Land' and 'Dragon Fly' return zero results respectively. Borderland should have worked for a regular text field. For all other desired matches you can use EdgeNGramTokenizerFactory. Cheers Avlesh On Mon, Oct 5, 2009 at 7:51 PM, Andrew McCombeeupe...@gmail.com wrote: Hi I am hoping someone can point me in the right direction with regards to indexing words that are concatenated together to make other words or product names. We have indexed a product database and have come across some search terms where zero results are returned. There are products in the index with 'Borderlands xxx xxx', 'Dragonfly xx xxx' in the title. Searches for 'Borderland' or 'Border Land' and 'Dragon Fly' return zero results respectively. Where do I look to resolve this? The product name field is indexed using a text field type. Thanks in advance Andrew
Re: A little help with indexing joined words
Using synonyms might be a better solution because the use of EdgeNGramTokenizerFactory has the potential of creating a large number of token which will artificially increase the number of tokens in the index which in turn will affect the IDF score. Well, I don't see a reason as to why someone would need a length based normalization on such matches. I always have done omitNorms while using fields with this filter. Yes, synonyms might an answer when you have limited number of such words (phrases) and their possible combinations. Cheers Avlesh On Mon, Oct 5, 2009 at 10:32 PM, Christian Zambrano czamb...@gmail.comwrote: Using synonyms might be a better solution because the use of EdgeNGramTokenizerFactory has the potential of creating a large number of token which will artificially increase the number of tokens in the index which in turn will affect the IDF score. A query for borderland should have returned results though. It is difficult to troubleshoot why it didn't without knowing what query you used, and what kind of analysis is taking place. Have you tried using the analysis page on the admin section to see what tokens gets generated for 'Borderlands'? Christian On 10/05/2009 11:01 AM, Avlesh Singh wrote: We have indexed a product database and have come across some search terms where zero results are returned. There are products in the index with 'Borderlands xxx xxx', 'Dragonfly xx xxx' in the title. Searches for 'Borderland' or 'Border Land' and 'Dragon Fly' return zero results respectively. Borderland should have worked for a regular text field. For all other desired matches you can use EdgeNGramTokenizerFactory. Cheers Avlesh On Mon, Oct 5, 2009 at 7:51 PM, Andrew McCombeeupe...@gmail.com wrote: Hi I am hoping someone can point me in the right direction with regards to indexing words that are concatenated together to make other words or product names. We have indexed a product database and have come across some search terms where zero results are returned. There are products in the index with 'Borderlands xxx xxx', 'Dragonfly xx xxx' in the title. Searches for 'Borderland' or 'Border Land' and 'Dragon Fly' return zero results respectively. Where do I look to resolve this? The product name field is indexed using a text field type. Thanks in advance Andrew
Re: A little help with indexing joined words
Would you mind explaining how omitNorm has any effect on the IDF problem I described earlier? I agree with your second sentence. I had to use the NGramTokenFilter to accommodate partial matches. On 10/05/2009 12:11 PM, Avlesh Singh wrote: Using synonyms might be a better solution because the use of EdgeNGramTokenizerFactory has the potential of creating a large number of token which will artificially increase the number of tokens in the index which in turn will affect the IDF score. Well, I don't see a reason as to why someone would need a length based normalization on such matches. I always have done omitNorms while using fields with this filter. Yes, synonyms might an answer when you have limited number of such words (phrases) and their possible combinations. Cheers Avlesh On Mon, Oct 5, 2009 at 10:32 PM, Christian Zambranoczamb...@gmail.comwrote: Using synonyms might be a better solution because the use of EdgeNGramTokenizerFactory has the potential of creating a large number of token which will artificially increase the number of tokens in the index which in turn will affect the IDF score. A query for borderland should have returned results though. It is difficult to troubleshoot why it didn't without knowing what query you used, and what kind of analysis is taking place. Have you tried using the analysis page on the admin section to see what tokens gets generated for 'Borderlands'? Christian On 10/05/2009 11:01 AM, Avlesh Singh wrote: We have indexed a product database and have come across some search terms where zero results are returned. There are products in the index with 'Borderlands xxx xxx', 'Dragonfly xx xxx' in the title. Searches for 'Borderland' or 'Border Land' and 'Dragon Fly' return zero results respectively. Borderland should have worked for a regular text field. For all other desired matches you can use EdgeNGramTokenizerFactory. Cheers Avlesh On Mon, Oct 5, 2009 at 7:51 PM, Andrew McCombeeupe...@gmail.com wrote: Hi I am hoping someone can point me in the right direction with regards to indexing words that are concatenated together to make other words or product names. We have indexed a product database and have come across some search terms where zero results are returned. There are products in the index with 'Borderlands xxx xxx', 'Dragonfly xx xxx' in the title. Searches for 'Borderland' or 'Border Land' and 'Dragon Fly' return zero results respectively. Where do I look to resolve this? The product name field is indexed using a text field type. Thanks in advance Andrew
Re: A little help with indexing joined words
fyi, if you don't want to turn off norms entirely, try this option in lucene 2.9 DefaultSimilarity: public void setDiscountOverlaps(boolean v) Determines whether overlap tokens (Tokens with 0 position increment) are ignored when computing norm. By default this is false, meaning overlap tokens are counted just like non-overlap tokens. Well, I don't see a reason as to why someone would need a length based normalization on such matches. I always have done omitNorms while using fields with this filter. -- Robert Muir rcm...@gmail.com
Re: A little help with indexing joined words
Zambrano, I was too quick to respond to your idf explanation. I definitely
did not mean that idf and length-norms are the same thing.
Andrew, this is how i would have done it -
First, I would create a field called prefix_text as undeneath in my
schema.xml
fieldType name=prefix_text class=solr.TextField
analyzer type=index
tokenizer class=solr.KeywordTokenizerFactory/
filter class=solr.LowerCaseFilterFactory/
filter class=solr.PatternReplaceFilterFactory
pattern=([^a-z0-9]) replacement= replace=all/
filter class=solr.RemoveDuplicatesTokenFilterFactory/
filter class=solr.EdgeNGramFilterFactory maxGramSize=100
minGramSize=1/
/analyzer
analyzer type=query
tokenizer class=solr.KeywordTokenizerFactory/
filter class=solr.LowerCaseFilterFactory/
filter class=solr.PatternReplaceFilterFactory
pattern=([^a-z0-9]) replacement= replace=all/
filter class=solr.PatternReplaceFilterFactory
pattern=^(.{20})(.*)? replacement=$1 replace=all/
filter class=solr.RemoveDuplicatesTokenFilterFactory/
/analyzer
/fieldType
Second, I would declare a field of this and populate the same (using
copyField) while indexing.
Third, while querying I would query on the both the fields. I would boost
the matches for original field to a large extent over the n-grammed field.
Scenarios where Dragon Fly is expected to match against Dragonfly in the
index, query on the original field would not give you any matches, thereby
bringing results from the prefix_token field right there on top.
Hope this helps.
Cheers
Avlesh
On Mon, Oct 5, 2009 at 11:10 PM, Christian Zambrano czamb...@gmail.comwrote:
Would you mind explaining how omitNorm has any effect on the IDF problem I
described earlier?
I agree with your second sentence. I had to use the NGramTokenFilter to
accommodate partial matches.
On 10/05/2009 12:11 PM, Avlesh Singh wrote:
Using synonyms might be a better solution because the use of
EdgeNGramTokenizerFactory has the potential of creating a large number of
token which will artificially increase the number of tokens in the index
which in turn will affect the IDF score.
Well, I don't see a reason as to why someone would need a length based
normalization on such matches. I always have done omitNorms while using
fields with this filter.
Yes, synonyms might an answer when you have limited number of such words
(phrases) and their possible combinations.
Cheers
Avlesh
On Mon, Oct 5, 2009 at 10:32 PM, Christian Zambranoczamb...@gmail.com
wrote:
Using synonyms might be a better solution because the use of
EdgeNGramTokenizerFactory has the potential of creating a large number of
token which will artificially increase the number of tokens in the index
which in turn will affect the IDF score.
A query for borderland should have returned results though. It is
difficult to troubleshoot why it didn't without knowing what query you
used,
and what kind of analysis is taking place.
Have you tried using the analysis page on the admin section to see what
tokens gets generated for 'Borderlands'?
Christian
On 10/05/2009 11:01 AM, Avlesh Singh wrote:
We have indexed a product database and have come across some search
terms
where zero results are returned. There are products in the index with
'Borderlands xxx xxx', 'Dragonfly xx xxx' in the title. Searches for
'Borderland' or 'Border Land' and 'Dragon Fly' return zero results
respectively.
Borderland should have worked for a regular text field. For all other
desired matches you can use EdgeNGramTokenizerFactory.
Cheers
Avlesh
On Mon, Oct 5, 2009 at 7:51 PM, Andrew McCombeeupe...@gmail.com
wrote:
Hi
I am hoping someone can point me in the right direction with regards to
indexing words that are concatenated together to make other words or
product
names.
We have indexed a product database and have come across some search
terms
where zero results are returned. There are products in the index with
'Borderlands xxx xxx', 'Dragonfly xx xxx' in the title. Searches for
'Borderland' or 'Border Land' and 'Dragon Fly' return zero results
respectively.
Where do I look to resolve this? The product name field is indexed
using
a
text field type.
Thanks in advance
Andrew
