Does anyone worked on the solr search to boost the result based on maximum search keyword match? Actually I am doing query on Solr to get the result based on multiple keywords search and need to boost the result based on maximum matches keyword.
Let say my search term is field:("suresh" or "ramesh" or "vikas"). Now if any result match all three word then should come first. If any any result match only two word then come 2nd position and so on.
Thanks !
Related
I am trying to use the eDismax Query Parser with the following requirements where a search query can be intepreted as a phrase and also individual words, but where phrase takes precedence over individual words.
Example:
Search query: We are cool
Results should be:
Documents fields with phrase 'we are cool' appearing top of list
Documents where fields comprises of either 'we', 'are', 'cool' where highest number of occurences take precedence.
How would I go about implementing this? Thanks.
The simplest way: use pf param boosting for that, check the doc here
So for example, adding this (if you had those two fields):
q=We are cool&pf=mytitle^10 mydescription
I'm looking into the possibility of de-boosting a set of documents during
query time. In my application, when I search for e.g. "preferences", I want
to de-boost content tagged with ContentGroup:"Developer" or in other words,
push those content back in the order. Here's the catch. I've the following
weights on query fields and boost query on source
qf=text^6 title^15 IndexTerm^8
As you can see, title has a higher weight.
Now, a bunch of content tagged with ContentGroup:"Developer" consists of a
title like "Preferences.material" or "Preferences Property" or
"Preferences.graphics". The boost on title pushes these documents at the
top.
What I'm looking is to see if there's a way to deboost all documents that are
tagged with ContentGroup:"Developer" irrespective of the term occurrence is
text or title. I tried something like, but didn't make any difference.
Source:simplecontent^10 Source:Help^20 (-ContentGroup-local:("Developer"))^99
I'm using edismax query parser.
Any pointers will be appreciated.
Thanks,
Shamik
You're onto something with your last attempt, but you have to start with *:*, so that you actually have something to subtract the documents from. The resulting set of documents (those not matching your query) can then be boosted.
From the Solr Relevancy FAQ
How do I give a negative (or very low) boost to documents that match a query?
True negative boosts are not supported, but you can use a very "low" numeric boost value on query clauses. In general the problem that confuses people is that a "low" boost is still a boost, it can only improve the score of documents that match. For example, if you want to find all docs matching "foo" or "bar" but penalize the scores of documents matching "xxx" you might be tempted to try...
q = foo^100 bar^100 xxx^0.00001 # NOT WHAT YOU WANT
...but this will still help a document matching all three clauses score higher then a document matching only the first two. One way to fake a "negative boost" is to give a large boost to everything that does not match. For example...
q = foo^100 bar^100 (*:* -xxx)^999
NOTE: When using (e)dismax, people sometimes expect that specifying a pure negative query with a large boost in the "bq" param will work (since Solr automatically makes top level purely negative positive queries by adding an implicit ":" -- but this doesn't work with "bq", because of how queries specified via "bq" are added directly to the main query. You need to be explicit...
?defType=dismax&q=foo bar&bq=(*:* -xxx)^999
We are trying to implement a very interesting search logic with custom boosting and I am wondering if Solr can support this.
We have the following fields in our index:
Name
Description
Keywords (array)
Each keyword will have an amount(int value) paired to it.
A search is run across Name, description and keywords field. If a keyword matches the search text, the corresponding index must be boosted based on the amount of the matching keyword only.
I've read through Solr DisMax and they can only boost a field using a fixed amount.
My scenario will be to boost the result by X amount based on matching keywords only.
Thanks in advance
The only viable solution i see to this problem (assuming ofcourse you DO NOT know the number of keywords in advance) would be to just make the query as a filter query (to skip the scoring stage), get all documents matching ( a bit problematic), then just sort them on your side using the matched term to build the a java Comparator.
Problems may arise when you get a particularly large number of documents, but you could probably side step this issue by pagination
If you don't have too much different amounts maybe you can try this on index-time:
Store "keywords" in different fields(dynamicfields->boost-*) based on it's amount:
boost-1 = keyword1,keyword4,keyword6 <br/>
boost-10 = keyword2<br/>
boost-100 = keyword5
You can search across all your boost fields(edismax), boost every dynamicfield with his amount in your (e)dismax conf(boost-1^1,boost-10^10,boost-100^100).
Is there any way to map analyzer to Query-types (phrase, range) similar to the way we do with Analyzer to field names?
I want to support exact match in case of phrase searches and search on even stemmed words if it's not a phrase search. During indexing I'm indexing both the original token and stemmed token at the same position.
Consider the following case:
document1 : feature flipping
document2 : feature flip
Tokens generated during indexing phase:
document1 : feature featur flipping flip
document2 : feature featur flip
feature & featur are at the same position and flipping & flip are at the same position
When I search using phrase query "feature flipping" query generated is
Your Query: +matchAllDocs:true +(alltext:("feature flipping"))
Lucene's: +matchAllDocs:true +alltext:"(feature featur) (flipping flip)"
And this returns both the documents. Is there any way to return only the exact match (document 1)? I thought that if it' possible to map analyzers to query-types, then i will skip phrase queries from stemFilter.
UPDATE
https://issues.apache.org/jira/browse/LUCENE-2892 is what I'm looking for.
Thanks
I want to provide for partial matching, so I am tacking on * to the end of search queries. What I've noticed is that a search query of gatorade will return 12 results whereas gatorade* returns 7. So * seems to be 1 or many as opposed to 0 or many ... how can I achieve this? Am I going about partial matching in Solr all wrong? Thanks.
First, I think Solr wildcards are better summarized by "0 or many" than "1 or many". I doubt that's the source of your problem. (For example, see the javadocs for WildcardQuery.)
Second, are you using stemming, because my first guess is that you're dealing with a stemming issue. Solr wildcards can behave kind of oddly with stemming. This is because wildcard expansion is based by searching through the list of terms stored in the inverted index; these terms are going to be in stemmed form (perhaps something like "gatorad"), rather than the words from the original source text (perhaps "gatorade" or "gatorades").
For example, suppose you have a stemmer that maps both "gatorade" and "gatorades" to the stem "gatorad". This means your inverted index will not contain either "gatorade" or "gatorades", only "gatorad". If you then issue the query gatorade*, Solr will walk the term index looking for all the stems beginning with "gatorade". But there are no such stems, so you won't get any matches. Similarly, if you searched gatorades*, Solr will look for all stems beginning with "gatorades". But there are no such stems, so you won't get any matches.
Third, for optimal help, I'd suggest posting some more information, in particular:
Some particular query URLs you are submitting to Solr
An excerpt from your schema.xml file. In particular, include A) the field elements for the fields you are having trouble with, and B) the field type definitions corresponding to those fields
so what I was looking for is to make the search term for 'gatorade' -> 'gatorade OR gatorade*' which will give me all the matches i'm looking for.
If you want a query to return all documents that match either a stemmed form of gatorade or words that begin with gatorade, you'll need to construct the query yourself: +(gatorade gatorade*). You could alternatively extend the SolrParser to do this, but that's more work.
Another alternative is to use NGrams and TokenFilterFactories, specifically the EdgeNGramFilterFactory. .
This will create indexes for ngrams or parts of words. Documents, with a min ngram size of 5 and max ngram size of 8, would index: Docum Docume Document Documents
There is a bit of a tradeoff for index size and time. One of the Solr books quotes as a rough guide: Indexing takes 10 times longer Uses 5 times more disk space Creates 6 times more distinct terms.
However, the EdgeNGram will do better than that.
You do need to make sure that you don't submit wildcard character in your queries. As you aren't doing a wildcard search, you are matching a search term on ngrams(parts of words).
My guess is the missing matches are "Gatorade" (with a capital 'G'), and you have a lowercase filter on your field. The idea is that you have filters in your schema.xml that preprocess the input data, but wildcard queries do not use them;
see this about how Solr deals with wildcard queries:
http://solr.pl/en/2010/12/20/wildcard-queries-and-how-solr-handles-them/
("Solr and wildcard handling").
From what I've read the wildcards only matched words with additional characters after the search term. "Gatorade*" would match Gatorades but not Gatorade itself. It appears there's been an update to Solr in version 3.6 that takes this into account by using the 'multiterm' field type instead of the 'text' field.
A better description is here:
http://bensch.be/the-solr-wildcard-problem-and-multiterm-solution