I am using solr for indexing some documents and then searching. I want to return those documents that have the same start as the search keywords higher in the results. How can i achieve that?
E.g.
If i the search keyword is "php"
and there are two documents with content :
php developer
ajax php
then i want to return 'php developer' first instead of 'ajax php'.
Any suggestions on how to return results in this order?
I am looking for some sort of an analyzer that only indexes the first word from the content of a field and then giving that field a lot of weight while querying. Maybe that can help. I couldnt find such an analyzer for my purposes.
You can boost the first tokens using payload. Refer to the link mentioned in Payloads
Related
Is there a way to force specific documents into SOLR search results?
I'm trying something like this but is not working:
/q=id:21321 OR myNormalSearchConditionsHereIncludingDismaxQUery
My goal is to have certain documents always show up in some search results, no matter what the query is.
you can use Solr MoreLikeThis component
This is just a quick thought i would make from your description.
With this you will no longer require a second query and caching the results.
Im using Solr 3.5.0, and in Schema I have enabled the LowerCaseFilterFactory in all needed fields, bbut When I search for example "shirts" im able to get the results, also when I search for "SHIRTS" i'm able to get expected results, but when I try to search with "shiRTs" its not giving the results. I know I'm missing some thing in Schema.
Please help me on this.
Thanks
Jeyaprakash.
Apply the same analysers and filters at both index and query time, so the the queries you search for match the tokens index.
As in your case -
If you apply the Lower case filter at index time but not at query time :-
Index token will be shirts, However as the search query is not analyzed SHIRTS or even Shirts will not match indexed shirts token.
The same would apply if you are using stemmers, stopwords or other filters.
http://wiki.apache.org/solr/AnalyzersTokenizersTokenFilters#Analyzers
Analyzers are components that pre-process input text at index time
and/or at search time. It's important to use the same or similar
analyzers that process text in a compatible manner at index and query
time. For example, if an indexing analyzer lowercases words, then the
query analyzer should do the same to enable finding the indexed words.
Hi
I have a very specific need in my company for the system's search engine, and I can't seem to find a solution.
We have a SOLR index of items, all of them have the same fields, with one of the fields being "Type", (And ofcourse, "Title", "Text", and so on).
What I need is: I get an Item Type and a Query String, and I need to return a list of search suggestion with each also saying how meny items of the correct type will that suggested string return.
Something like, if the original string is "goo" I'll get
Goo 10
Google 52
Goolag 2
and so on.
now, How do I do it?
I don't want to re-query SOLR for each different suggestion, but if there is no other way, I just might.
Thanks in advance
you can try edge n-gram tokenization
http://search.lucidimagination.com/search/document/CDRG_ch05_5.5.6
You can try facets. Take a look at my more detailed description ('Autocompletion').
This was implemented at http://jetwick.com with Solr ... now using ElasticSearch but the Solr sources are still available and the idea is also the identical https://github.com/karussell/Jetwick
The SpellCheckComponent of Solr (that gives the suggestions) have extended results that can give the frequency of every suggestion in the index - http://wiki.apache.org/solr/SpellCheckComponent#Extended_Results.
However, the .Net component SolrNet, does not currently seem to support the extendedResults option: "All of the SpellCheckComponent parameters are supported, except for the extendedResults option" - http://code.google.com/p/solrnet/wiki/SpellChecking.
This is implemented using a facet field query with a Prefix set. You can test this using the xml handler like this:
http://localhost:8983/solr/select/?rows=0&facet=true&facet.field=type&f.type.prefix=goo
CouchDB gives an opportunity to search values from startkey, for exact key-value pair etc
But is there any way to search for substring in specified field?
The problem is like this. Our news database consists of about 40,000 news documents. Say, they have title, content and url fields. We want to find news documents which have "restaurant" in their title. Is there any way to do it?
View Collation wiki page tells nothing :( And it seems strange to me that there's no tool to handle this problem and all I can to do is just parsing JSON results with Python, PHP or smth else. In MySQL it's simply LOCATE() function..
Use couchdb-lucene.
Be careful here. Lucene is not always the best answer.
If your only searching one limited field and only searching for a word like restaurant then lucene which is really meant to tokenize large texts/documents can be way overkill, you can get the same effect by splitting the title.
function(doc){
var stringarray = doc.title.split(" ");
for(var idx in stringarray)
emit(stringarray[idx],doc);
}
Also Lucene and Couchdb do not support substring search, where the string is not in the beginning of a word.
I use solr to search for documents and when trying to search for documents using this query "id:*", I get this query parser exception telling that it cannot parse the query with * or ? as the first character.
HTTP Status 400 - org.apache.lucene.queryParser.ParseException: Cannot parse 'id:*': '*' or '?' not allowed as first character in WildcardQuery
type Status report
message org.apache.lucene.queryParser.ParseException: Cannot parse 'id:*': '*' or '?' not allowed as first character in WildcardQuery
description The request sent by the client was syntactically incorrect (org.apache.lucene.queryParser.ParseException: Cannot parse 'id:*': '*' or '?' not allowed as first character in WildcardQuery).
Is there any patch for getting this to work with just * ? Or is it very costly to do such a query?
If you want all documents, do a query on *:*
If you want all documents with a certain field (e.g. id) try id:[* TO *]
Lucene doesn't allow you to start WildcardQueries with an asterisk by default, because those are incredibly expensive queries and will be very, very, very slow on large indexes.
If you're using the Lucene QueryParser, call setAllowLeadingWildcard(true) on it to enable it.
If you want all of the documents with a certain field set, you are much better off querying or walking the index programmatically than using QueryParser. You should really only use QueryParser to parse user input.
id:[a* TO z*] id:[0* TO 9*] etc.
I just did this in lukeall on my index and it worked, therefore it should work in Solr which uses the standard query parser. I don't actually use Solr.
In base Lucene there's a fine reason for why you'd never query for every document, it's because to query for a document you must use a new indexReader("DirectoryName") and apply a query to it. Therefore you could totally skip applying a query to it and use the indexReader methods numDocs() to get a count of all the documents, and document(int n) to retrieve any of the documents.
If you are just trying to get all documents, Solr does support the *:* query. It's the only time I know of that Solr will let you begin a query with an *. I'm sure you've probably seen this as the default query in the Solr admin page.
If you are trying to do a more specific query with an * as the first character, like say id:*456 then one of the best ways I've seen is to index that field twice. Once normally (field name: id), and once with all the characters reversed (field name: reverse_id). Then you could essentially do the query id:456 by sending the query reverse_id:654 instead. Hope that makes sense.
You can also search the Solr user group mailing list at http://www.mail-archive.com/solr-user#lucene.apache.org/ where questions like this come up quite often.
The following Solr issue is a request to be able to configure the default lucene query parser.
https://issues.apache.org/jira/browse/SOLR-218
In this issue you can find the following description how to 'patch' Solr. This modification would allow you to start queries with a *.
Jonas Salk: I've basically updated only one Java file: SolrQueryParser.java.
public SolrQueryParser(IndexSchema schema, String defaultField) {
...
setAllowLeadingWildcard(true);
setLowercaseExpandedTerms(true);
...
}
...
public SolrQueryParser(QParser parser, String defaultField, Analyzer analyzer) {
...
setAllowLeadingWildcard(true);
setLowercaseExpandedTerms(true);
...
}
I'm not sure if setLowercaseExpandedTerms is needed...
I'm assuming with id:* you're just trying to match all documents, right?
I've never used solr before, but in my Lucene experience, when ingesting data, we've added a hidden field to every document, then when we need to return every record we do a search for the string constant in that field that's the same for every record.
If you can't add a field like that in your situation, you could use a RegexQuery with a regex that would match anything that could be found in the id field.
Edit: actually answering the question. I've never heard of a patch to get that to work, but I would be surprised if it could even be made to work reasonably well. See this question for a reason why unconstrained PrefixQuery's can cause a problem.
Actually, I have been using a workaround for this. I append a character to the id, eg: A1, A2, etc.
With such values in the field, it is possible to search using the query id:A*
But would love to find whether a true solution exists.