As the title says which one I need to use for boosting in solr. whether its q.alt or bq. I tried the boosting in both however I'm not clear on how the boosting is working. Because in q.alt I got the correct results when I specified boosting value as 1000 at the same time I got the same results in bq with the boosting value as 2
Can someone help me to get the best practices for boosting?
My SOLR version is 3.5.
It depends upon what are you trying to boost.
Use qf (query fields) - to boost the individual search fields which have different weightage.
for e.g. For a document title has a higher weightage then description then you would use title^2 description^1
q.alt is just an alternate query factor in case on q is specified.
Use bq and bf for boosting certain matches, ranges or when the need to apply some functions on them. These usually are the extar boost and not the part of the search boost.
for e.g. for latest documents you would boost by date, or Price range or you want to boost on sum of fields etc ...
use qf parameter for boosting
Dismax Query Parser Wiki
Related
I would like to apply negative boost on the documents which does not have specific fields. But its not working and results the same boost value for the document with and without that field.Any pointers would be of great help.
bf=if(not(exists('image-small_string')),0,-500)
The answer is to boost those documents that do not match your query, instead of trying to apply a negative boost to those that do.
To boost documents that has a specific field, you can use bq=foo:[* TO *]^5 (and adjust the boost factory to match the behaviour you're looking for).
I want boost at query time all documents that have value user_id=2. Basically I want on the top of my results all the documents belonged to a specific user.
After looking at some Solr resources I ended up writing a query like, but it is not working properly.
/solr/public-main/select?q={!boost b=if(div(155623,user_id),2,1)}sometext&wt=json&indent=true&debugQuery=true
Any hints?
Thanks
You don't need to use the boost with a dynamic boost. Apply a boost query which will boost all the documents that match the query: bq=user_id:2^4. Adjust 4 to a suitable boost value depending on the rest of your boosts (if any in q or qf).
One option is to have a function query with fl=x,y,userexists:exists(query({!v='user_id:2'})) and then u can sort by userexists and then by score field.
I'm doing a "More Like This" query on 3 text fields, but I'd like to also boost the results based on a numeric "views" field. In a normal query I'd add a boost term like "{!boost b=scale(sqrt(views),1,2)}" or something similar, but this doesn't seem to work if I specify it in the mlt.qf field. Is formula based boosting allowed in MLT queries?
According to the More Like This page on the Solr Wiki, the mlt.qf field allows for boosts.
Query fields and their boosts using the same format as that used in DisMaxQParserPlugin. These fields must also be specified in mlt.fl.
Checkout the syntax for boosting with the DisMaxQParserPlugin and you should be able to get the boosting you desire.
Also, check out the answer to this previous question - Is it possible to boost mlt queries in Solr
All my results are of type "active, inactive, historical" - this is a field indexed by Solr.
I want my results to be returned with a boost to type="active".
I could do ordering which will suffice, but its not great.
So, when a user searches for a term "sick", they get the most relevant results to sick, but with a higher boost for documents where its active.
Not just a sorted result set!
You can use the edismax parser and the following boost query bq paramter to get your desired results to be boosted to the top...
http://localhost:8983/solr/select/?q=sick&defType=edismax&bq=type:active^5.0
In this example you are adding a boost query to increase the relevancy of documents whose type is active.
Here are some more examples on the Solr Wiki DisMaxQParserPlugin page.
The above example will create an additive boost.
If you want an multiplicative boost for "type=active" you could add:
&boost=if(termfreq(type,"active"),2,1)
Which gives a factor 2 boost for "type=active"
I already have the boost determined before hand. I have a field in the solr index called boost1 . This boost field will have a value from 1 to 10 similar to google PR rank. This is the boost that should be applied to every query ran in solr. here are the fields in my index
Id
Title
Text
Boost1
The boost field should be apply to every query. I am trying to implement functionality similar to Google PR rank. Is there a way to do this using solr?
you can add the boost during query e.g.
q={!boost b=boost1}
How_can_I_boost_the_score_of_newer_documents
However, this may need to be added explicitly by you.
If you are using dismax or edismax with the request handler, The bf (Boost Functions) parameter could be used to boost the documents.
http://wiki.apache.org/solr/DisMaxQParserPlugin#bf_.28Boost_Functions.29
bf=boost1^0.5
This can be added to defaults with the request handler definition, so that they are applied to all the search queries.
you can use function queries to vary the amount of boost FunctionQuery
I think you need to use index time document boosts. See this if you are indexing XML or this if using DataImportHandler.