Suppose I want to create a recommendation system to suggest people you should connect with based off of certain attributes that I know about you and attributes I have about other people that are stored in a Solr index. Is it possible to query the index with a list of attributes (along with boosts for each attribute) and have Solr return scored results even if some of my fields return no matches? The way that I understand that Solr works is that if one of your fields doesn't contain a match in any documents found in your index, you get zero results for the entire query (even if other fields in the query matched) - is that right? What I would hope is that I could query the index and get a list of results back in order of a score given based on how many (and which) fields matched to something, even if some fields have no matches, for example:
Say that there are 2 people documents stored in the index as follows (figuratively):
Person 1:
Industry: Manufacturing
City: Oakland
Person 2:
Industry: Manufacturing
City: San Jose
And say that I perform a pseudo-Solr query that basically says "Search for everyone whose industry is equal to manufacturing and whose city is equal to Oakland". What I would like is to receive both results back in the result set, even though one of the "Persons" does not reside in Oakland. I just want that person to come back as a result with a lower score than Person1. Is this possible? What might a solr query look like to handle this? Assume that I have many more than 2 attributes for each person (so saying that I can use "And" and "Or" in my solr query isn't really feasible.. or is it?) Thanks in advance for your helpful input! (PS I'm using Solr 3.6)
You mention using the AND operator, which is likely your problem.
The default behavior of Lucene, and Solr, query syntax is exactly what you are asking for. A query like:
industry:manufacturing city:oakland
Will match either, with scoring preference on those that match both. See the lucene query syntax documentation
You can use the bq parameter (boost query) does not affect matching, but affects the scores only.
http://localhost:8983/solr/persons/select?q=industry:manufacturing&bq=City:Oakland^2
play with the boosting factor at the end to get the correct balance between matching score, and boosting score.
Related
I'm attempting to query solr for documents, given a basic schema with the following field names, data types irrelevant:
I'm attempting to match documents that match at least one of the following:
occupation, name, age, gender but i want to OR them together
How do you OR together many terms, and enforce the document to match at least one?
This seems to be failing: +(name:Sarah age:24 occupation:doctor gender:male)
How do you convert a boolean expression into solr query syntax? I can't figure out the syntax with + and - and the default operator for OR.
Still I don't get your requirement but you just need to query like:
+(age:24 OR gender:male)
Or if you want data for multiple value in same field with OR condition like.
i.e. You get data of age:24 and age:25 both.
+(age:24 OR age:25 OR gender:male)
Then you can:
+(age:(24 25) OR gender:male)
If it is't your requirement, then let me know.
If you want to make it as simple as possible for the client, just go for the dismax[1] or edismax[2] query parser.
Specifically you can configure a request parameter called "qf" :
"The qf parameter introduces a list of fields, each of which is assigned a boost factor to increase or decrease that particular field’s importance in the query. For example, the query below:
qf=fieldOne^2.3 fieldTwo fieldThree^0.4
assigns fieldOne a boost of 2.3, leaves fieldTwo with the default boost (because no boost factor is specified), and fieldThree a boost of 0.4.
These boost factors make matches in fieldOne much more significant than matches in fieldTwo, which in turn are much more significant than matches in fieldThree." from the wiki
Then you can just pass a free text query, and it will be searched in the fields you specified, giving also different importance to each one, if necessary.
[1] https://lucene.apache.org/solr/guide/6_6/the-dismax-query-parser.html
[2] https://lucene.apache.org/solr/guide/6_6/the-extended-dismax-query-parser.html
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
On our webshop I want to implement a feature which should do the following:
If a user e.g. searches for "phone magnum", there will be no results.
If there were no results I want to give him the possibility to see
that search for "phone" will give him 139 results
and search for "magnum" will get 12 results.
I don't want to start several queries only for getting those counts. But at the moment I have no Idea how to do that.
I read the Solr-wiki for faceting, but didn't find anything useful for my problem. Maybe I missed something ....
Not sure why you want to avoid multiple queries. If your first search on the phrase "phone magnum" does not return any results, you could issue one query per search keyword with rows=0 which will give you only the counts. This should be efficient, since you are not building any result documents and only getting the result counts.
However, if you really want to avoid the subsequent queries, here is one apporach: Have a field in your index which does not take IDF into account. (See this on how to do that.) Once that field is available (call it say name_no_idf) issue a query against this field name_no_idf:(phone magnum). Notice that this is not a phrase search.
The documents which contain both phone and magnum in the name_no_idf field will get a score of 2, while the docs matching only one word will get a score of 1. To this query you add facet=true&facet.field=name. Then the facet counts you get for these two words will be the counts you are looking for. But few warnings:
if one of the words is very infrequent, you may need to increase facet.limit
facet queries are expensive
I'd like to submit a query to SOLR/Lucene, plus a list of document IDs. From the query, I'd like the usual top-N scored results, but I'd also like to get the scores for the named documents... no matter how low they are.
Can anyone think of an easy/supported way to do this in a single index scan, where the scores for the 'added' (non-ranking/pinned-for-inclusion) docs are comparable/same-scaled as those for the top-N results? (Patching SOLR with specialized classes would be OK; I figure that's what I may have to do if there's no existing support.)
Or failing that, could it be simulated with a followup query, ideally in a way that the named-document scores could be scaled to be roughly comparable to the top-N for the reference query?
Alternatively -- and perhaps as good or better for my intended use -- could I make a single request against a SOLR/Lucene index which includes M (with M=2 or more) distinct queries, and return the results that are in the top-N for any of the M queries, and for every result include its score against all M of the distinct queries?
(Even in my above formulation, the list of documents that I want scored along with a new query will typically have been the results from a prior query.)
Solutions or even just fragments of possible approaches appreciated!
I am not sure if I understand properly what you want to achieve but wouldn't a simple
q: (somequery) OR id: (1 OR 2 OR 4)
be enough?
If you would want both parts to be boosted by the same scale (I am not sure if this isn't the default behaviour of Solr) you would want to use dismax or edismax and your query would change to something like:
q: (somequery)^10 OR id: (1 OR 2 OR 4)^10
You would then have both the elements defined by the IDs and the query results scored the same way.
To self-answer, reporting what I've found since posting...
One clumsy option is the explainOther parameter, which takes another query. (This query could be a OR list of interesting document IDs.) The response will then include a full scoring explanation for documents which match this other query. explainOther only has effect when combined with the also-required debugQuery parameter.
All that debug/explain information is overkill for the need, but may be useful, or the code paths that implement it might provide a guide to making a hypothetical new more narrowly-focused 'scoreOther' option.
Another option would be to make use of pseudo-field calculated using the query() function to report how any set of results score on some other query/queries. So if for example the original document set was the top-N from query_A, and then those are the exact documents that you also want to score against query_B, you would execute query_A again with a reporting-field …&fl=bscore:query({!dismax v="query_B"})&…. Then the document's scores against query_B would be included in the output (as bscore).
Finally, the result-grouping functionality can be used both collect the top-N for one query and scores for lesser documents intersecting with other queries in one go. For example, if querying for query_B and adding …&group=true&group.query=query_B&group.query=query_A&…, you'll get back groups that satisfy query_B (ranked by query_B), and that satisfy both query_B and query_A (but again ranked by query_B). This could be mixed with the functional field above to get the scores by another query (like query_A) as well.
However, all groups will share the same sort order (from either the master query or something specified by a group.sort parameter), so it's not currently possible (SOLR-4.0.0-beta) to get several top-N results according to different scorings, just the top-Ns according to one scoring, limited by certain groups. (There's a comment in the source code suggesting alternate sorts per group may be envisioned as a future capability.)
Is it possible in solr to index key-value pairs for a single document, like:
Document ID: 100
2011-05-01,20
2011-08-23,200
2011-08-30,1000
Document ID: 200
2011-04-23,10
2011-04-24,100
and then querying for documents with a specific value aggregation in a specific time range, i.e. "give me documents with sum(value) > 0 between 2011-08-01 and 2011-09-01" would return the document with id 100 in the example data above.
Here is a post from the Solr User Mailing List where a couple of approaches for dealing with fields as key/value pairs are discussed.
1) encode the "id" and the "label" in the field value; facet on it;
require clients to know how to decode. This works really well for simple
things where the the id=>label mappings don't ever change, and are
easy to encode (ie "01234:Chris Hostetter"). This is a horrible approach
when id=>label mappings do change with any frequency.
2) have a seperate type of "metadata" document, one per "thing" that you
are faceting on containing fields for id and the label (and probably a
doc_type field so you can tell it apart from your main docs) then once
you've done your main query and gotten the results back facetied on id,
you can query for those ids to get the corrisponding labels. this works
realy well if the labels ever change (just reindex the corrisponding
metadata document) and has the added bonus that you can store additional
metadata in each of those docs, and in many use cases for presenting an
initial "browse" interface, you can sometimes get away with a cheap
search for all metadata docs (or all metadata docs meeting a certain
criteria) instead of an expensive facet query across all of your main
documents.