I have a database which I have indexed in Lucene (using Pylucene) by section (specified by markup in the document) using lucene's fields. This index seems to work fine. I can search it using the default field which is simply the entire document and get reasonable results.
The problem is, when I search it using a specific section (not the default), I expect to get a certain number of results back (as specified by IndexSearcher.search(query, results)), but instead it might simply return nothing. So my question is: how can I get it to return a ranked list with the number of results I specify?
The only place I specify the field is in the QueryParser, by calling:
QueryParser(Version.LUCENE_CURRENT, field, StandardAnalyzer)
I would verify the index using Luke (which is something I do often when modifying my index strategy).
Related
I have typesense server running and working. However I have found strange behaviour. There are documents in index with string column called "product_number". And there are product numbers in format "BKP001", "BKP002", .... "BKP999". There is 60 such documents.
However, when I query typesense and search for "BKP", it finds only 4 random matching documents. Strange is that if I do more specific search for "BKP01", it returns 4 documents "BKP010", "BKP011", "BKP012" and "BKP013".
And when I search for "BKP03" then it returns 4 documents "BKP031", "BKP032", "BKP033" and "BKP034". So it is clear that all the documents are correctly in index.
What could be the reason why it doesn't find all the documents ?
When there are several possible prefix matches for a particular keyword, Typesense limits the number of results picked for performance reasons, until more of the keyword is typed. If you want all results to be returned, you want to add max_candidates=1000 and exhaustive_search=true as search parameters.
You also want to make sure that you're using the latest version of Typesense as relevance improvements are regularly released with each version.
I am using Lucene.net via Kentico. I am trying to boost results that have a particular value in a field. For example:
myfield:"myvalue"^2
Unfortunately this is treated as a search term and alters the scores (via tf and idf etc) anyway.
Is there a way of boosting a result based on the presence of a value, but not including that value as a search term?
update
So I want to boost the score of records that contain that value in that field only, its not a search value in any way.
Failing that, as I am actually using two indexes, could I apply a boost to a particular index? For example, items from in index-1 have a slightly higher score overall than those from index-2
If you added this field in the "Search Condition" then behind the scenes it adds a "+" to the value, so the lucene is rendering:
+(myfield:"myvalue"^2)
Which then requires the field.
I believe (you will have to test) if you add a Smart Search Filter, set the value to myfield:"myValue"^2 and then set the "Filter is conditional" to false, this should properly add in your field to the lucene to boost, then just wrap the filter with some <div style="display:none"></div> to hide it.
Point that to your Results and see if it does the trick!
I am using Solr 4.1.0 and I'm facing a strange issue. If I give a value to search for a field, even be it exact or involving a wildcard, it gives me 0 search results. On the other hand if I just give the field name and a * in place of value, I get all the results.
Also, if I search in the text field, i.e where I have copied values of all my fields, it gives me correct output. text is by default, my catch-all for all fields. feature is a field which has value Butter.
So now, what is happening here is that if I try to find in the actual field with the exact value or even with starting alphabet and a *, it doesn't give me a value while if I search in the text field, which is a catch-all field, I'm able to retrieve the value. Although if I try to find in the feature field using *, it gives me complete result list correctly.
You can view the logs for text:Butter here, logs for feature:Butter here, logs for feature:B* here and logs for feature:* here
I'm facing this issue with this particular field only. Any pointers to what could be the reason behind this strange problem?
If you search without the field name, Solr is going to search in the default search field.
So make sure you are marking the fields you want to search on as default.
If you are using dismax query handler, you can add them to the qf parameter.
Also, for Wildcard Queries check [Analyzers][1]
On wildcard and fuzzy searches, no text analysis is performed on the search word.
As no analysis is done at query time for wilcard searches and hence the lower casing, stemming would not be applied during query time but just the index time.
In Lucene, using a Standard Analyzer, I want to make fields with space searchable.
I set Field.Index.NOT_ANALYZED and Field.Store.YES using the StandardAnalyzer
When I look at my index in LUKE, the fields are as I expected, a field and a value such as:
location -> 'New York'.
Here I found that I can use the KeywordAnalyzer to find this value using the query:
location:"New York".
But I want to add another term to the query. Let's say a have a body field which contains the normalized and analyzed terms created by the StandardAnalyzer. Using the KeywordAnalyzer for this field I get different results than when I use the StandardAnalyzer.
How do I combine two Analyzers in one QueryParser, where one Analyzer works for some fields and another one for another fields. I though of creating my own Analyzer which could behave differently depending on the field, but I have no clue how to do it.
PerFieldAnalyzerWrapper lets you apply different analyzers for different fields.
I'm running a simple test--trying to index something and then search for it. I index a simple document, but then when a search for a string in it, I get back what looks to be an empty document (it has no fields). Lucene seems to be doing something, because if I search for a word that's not in the document, it returns 0 results.
Any reason why Lucene would reliably return a document when it finds one that matches the given query, and yet that document has nothing in it?
More details:
I'm actually running Lucandra (Lucene + Cassandra). That certainly may be a relevant detail, but not sure.
The fields are set to Field.Store/YES and Field.Index/ANALYZED
Interestingly, I'm able to get this to work just fine on my local machine, but when we put it on our main server (which is a multi-node cassandra setup), I get the behavior described above. So this seems like probably the relevant detail, but unfortunately, I see no error message to clue me in to what specifically is causing it.
Unsure if this will work with Lucandra, but you have tried opening the index using Luke? Viewing the index contents with Luke might help
It's hard to tell what the problem is since you only provide a very abstract description. However, it sounds a bit like you are not storing the field value in the index. There are different modes for indexing a field. One option determines whether the original value is stored in the index to retrieve it later:
http://lucene.apache.org/java/3_0_0/api/core/org/apache/lucene/document/Field.Store.html
See also the description of the enclosing class Field
Read: http://anismiles.wordpress.com/2010/05/27/lucandra-an-inside-story/