Solr does not search data in correct fashion - solr

We have a customer web application, which uses Apache Solr APIs internally. We do not have access to the SolrUI on customer site.
Due to recent changes in Solr at customer end, whenever we try to search the data like
NAME:PRANAV AND AGE:1, Solr does not show any results.(shows numFound:0)
whereas when we search
NAME=PRANAV AND AGE:1, it gives the result.(shows numFound value greater than 0)
So String searches works with = and numeric search works with :.
But when we search
NAME=PRA* , we do not get any result in Solr. (shows numFound:0)
Can someone please advise, what should be changed on Solr side to correct the searches?
We want to have wild card searches (*, ?) to work and also String search should work with : instead of =.

Related

How can I view actually stored transformed Solr text field values?

When Solr returns a document, the field values match those that where passed to the Solr indexer.
However especially for TextFields Solr typically uses a modified value where (depending on the definition in the schema.xml) various filters are applied, typicall:
conversion to lower case
replacing of synonyms
removal of stopwords
application of stemming
One can see the result of the conversion for specific texts by using Solr Admin > Some core > Analysis. There is a tool called Luke and the LukeRequestHandler but it seems I can only view the values passed to Solr but not the tranformed variant. One can also take a look at the index data on the disk but they seem to be stored in a binary format.
However, non of these seem to enable me to see the actual value as stored.
The reason for asking is that I've created a text field based on a certain filter chain which according to Solr Admin > Analysis transforms the text correctly. However when searching for a specific word in the transformed text it won't find it.

Solr: How to search records ignoring case in field type "string"?

I have indexed the following record in my collection
{
"app_name":"atm inspection",
"appversion":1,
"id":"app_1427_version_2449",
"icon":"/images/media/default_icons/app.png",
"type":"app",
"app_id":1427,
"account_id":556,
"app_description":"inspection",
"_version_":1599625614495580160}]
}
and It's working fine unless an until i search records case sensitively i.e if i write following Solr query to search records whose app_name contains atm then Solr is returning above response which is a correct behaviour.
http://localhost:8983/solr/NewAxoSolrCollectionLocal/select?fq=app_name:*atm\ *&q=*:*
However, If i execute following Solr query to search records whose app_name contains ATM
http://localhost:8983/solr/NewAxoSolrCollectionLocal/select?fq=app_name:*ATM\ *&q=*:*
Solr is not returning above response because ATM!=atm.
Can someone please help me with the Solr query to search records case insensitively.
Your help is greatly appreciated.
You can't. The field type string requires an exact match (it's a single, unprocessed token being stored for the field value).
The way to do it is to use a TextField with an associated Tokenizer and a LowercaseFilter. If you use a KeywordTokenizer, the whole token will be kept intact (so it won't get split as you'd usually assume with a tokenizer), and since it's a TextField it can have a analysis chain associated - allowing you to add a LowercaseFilter.
The LowerCaseFilter is multiterm aware as far as I remember, but remember that wildcard queries will usually not have any filters applied. You should therefor lowercase the value before creating your query yourself (even if it probably will work in this simple case).

Elements getting added in Solr index but not able to search elements as desired

I'm working with solr to store web crawling search results to be used in a search engine. The structure of my documents in solr is the following:
{
word: The word received after tokenizing the body obtained from the html.
url: The url where this word was found.
frequency: The no. of times the word was found in the url.
}
When I go the Solr dashboard on my system, which is http://localhost:8983/solr/#/CrawlerSearchResults/query I'm able to find a word say "Amazon" with the query "word: Amazon" but on directly searching for Amazon I get no results. Could you please help me out with this issue ?
Image links below.
First case
Second case (No results)
Thanks,
Nilesh.
In your second example, the value is searched against the default search field (since you haven't provided a field name). This is by default a field named _text_.
To support just typing a query into the q parameter without field names, you can either set the default field name to search in with df=wordin your URL, or use the edismax query parser (defType=edismax) and the qf parameter (query fields). qf allows multiple fields and giving them a weight, but in your case it'd just be qf=word.
Second - what you're doing seems to replicate what Lucene is doing internally, so I'm not sure why you'd do it this way (each word is what's called a "token", and each count is what's called a term frequency). You can write a custom similarity to add custom scoring based on these parameters.

Solr Exact Query

I am using SolrNet to try and perform an exact query search
I have a document with the URL stored in Solr as : file://C:/Users/me/docs/X%20Item3
I want to match all documents that contain "X Item", so will be looking for a "X Item"
I have
new SolrQueryByField("url", "*\"X Item\"*");
But this does not return the document. I also do not want to have to convert space characters to %20 but I may have to if Solr will not do it for when it parses the query.
Help appreciated
Solr does not support wildcard searches by default at the beginning of a term. You can work around this by adding a ReversedWildcardFilter to the field indexing definition.
Depending on the kind of searches performed, you could also split on / to index each part of the path separately, or just the file name.
You shouldn't have to convert spaces to %20, as that should be performed by the client library (I'm not familiar with how SolrNet does it, but it really should abstract that away from you) when making an HTTP request.

Searching wiki URLs using Solr

I am trying to index and search a wiki on our intranet using Solr. I have it more-or-less working using edismax but I'm having trouble getting main topic pages to show up first in the search results. For example, suppose I have some URLs in the database:
http://whizbang.com/wiki/Foo/Bar
http://whizbang.com/wiki/Foo/Bar/One
http://whizbang.com/wiki/Foo/Bar/Two
http://whizbang.com/wiki/Foo/Bar/Two/Two_point_one
I would like to be able to search for "foo bar" and have the first link returned as the top result because it is the main page for that particular topic in the wiki. I've tried boosting the title and URL field in the search but the fieldNorm value for the document keeps affecting the scores such that sub-pages score higher. In one particular case, the main topic page shows up on the 2nd results page.
Is there a way to make the First URL score significantly higher than the sub categories so that it shows up in the top-5 search results?
One possible approach to try:
Create a copyField with your url
Extract path only (so, no host, no wiki)
Split on / and maybe space
Lowercase
Boost on phrase or bigram or something similar.
If you have a lot of levels, maybe you want a multivalued field, with different depth (starting from the end) getting separate entries. That way a perfect match will get better value. Here, you should start experimenting with your real searches.

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