Apache solr - more like this score - apache

I have a small index with ~1000 documents with only two fields:
- id (string)
- content (text_general)
I noticed that when I do MLT search by id for similar content, the original document(which id is the searched id) have a score 5.241327.
There is 1:1 duplicated document and for the duplicated content it is returning score = 1.5258181. Why? Why it is not 5.241327 when it is 100% duplicate.
Another question is can I in any way to get similarity documents by content by passing some text in the query.
Example:
/mlt/?q=content:Some encoded long text&mlt.fl=content
I am trying to check if there is similar content uploaded and the check must be performed at new content upload time.

It might be worth to try some different parameters. I also use MLT on only one field, I use the following parameters:
'mlt.boost': 'true',
'mlt.fl': 'my_field_name',
'mlt.maxqt': 1000,
'mlt.mindf': '0',
'mlt.mintf': '0',
'qt': 'mlt',
'rows': '10'
See http://wiki.apache.org/solr/MoreLikeThis for an explanation of the parameters. I think with a small index mindf might be important and I see the default mintf (term frequency) is 2, so I assume an ID is only one term, so this is probably ignored!

First, how does Solr More-Like-This works?
A regular Solr query is conducted (e.g. "?q=content:Some encoded long text&.....".
For each document returned by the above query, More-Like-This conduct More like this query...
So, the first result set "response", is just like any Solr query results set.
The More-Like-This appears below and start with something like that (Json format):
"moreLikeThis":{
"57375":{"numFound":18155,"start":0,"docs":["
For an explanation about More Like This algorithm, please read that:
http://blog.brattland.no/node/18
and: http://cephas.net/blog/2008/03/30/how-morelikethis-works-in-lucene/
If you didn't solved the problem yet, please let me know and I will guide you through.

Related

BigQuery: Convert a text column to UTF-8

I want to start a Vertex AI AutoML Text Entity Extraction Batch Prediction Job, but in my own experience, texts ("content" field in the JSONL structure), must also accomplish the following two features:
Every text's size in bytes, must be between 10 and 10000 bytes: DONE
Every text encoding must be UTF-8: UNKNOWN
My original data is stored in BigQuery, so I'll have to export it to Google Cloud Storage for later batch prediction. To take advantage of BigQuery optimization, I want to accomplish the 2 previous tasks in the BigQuery data source table itself. I have checked Google's official documentation, and the closest I have got to some related information, is this; however not accurate VS what I want. BTW, the query looks as follows:
WITH mydata AS (
SELECT
CASE
WHEN BYTE_LENGTH(posting)>10000 THEN LEFT(posting, 9950)
WHEN BYTE_LENGTH(posting)<10 THEN CONCAT(posting, " is possibly an skill")
ELSE posting
END AS posting
FROM `my-project.Machine_Learning_Datasets.sample-data-source` -- Modified for data protection
)
SELECT
posting as content, -- Something needs to be done here
"text" as mimeType
FROM mydata
And my-project.Machine_Learning_Datasets.sample-data-source schema looks as follows:
Field name
Type
Mode
Records
posting
STRING
NULLABLE
100M
Any ideas?
The following answer did the job, FYI:
WITH
mydata AS (
SELECT
CASE
WHEN BYTE_LENGTH(posting)>10000 THEN LEFT(posting, 9950)
WHEN BYTE_LENGTH(posting)<10 THEN CONCAT(posting, " is possibly an skill")
ELSE
posting
END
AS posting
FROM
`my-project.Machine_Learning_Datasets.sample-data-source` )
SELECT
REGEXP_REPLACE(posting, r'[^\x00-\x7F]+', '') AS content,
"text/plain" AS mimeType
FROM
mydata
UPDATE: This case has been considered, for an improved workaround.
Thanks!

Amazon CloudSearch returns false results

I have a DB of articles, and i would like to search for all the articles who:
1. contain the word 'RIO' in either the title or the excerpt
2. contain the word 'BRAZIL' in the parent_post_content
3. and in a certain time range
The query I search with (structured) was:
(and (phrase field=parent_post_content 'BRAZIL') (range field=post_date ['2016-02-16T08:13:26Z','2016-09-16T08:13:26Z'}) (or (phrase field=title 'RIO') (phrase field=excerpt 'RIO')))
but for some reason i get results that contain 'RIO' in the title, but do not contain 'BRAZIL' in the parent_post_content.
This is especially weird because i tried to condition only on the title (and not the excerpt) with this query:
(and (phrase field=parent_post_content 'BRAZIL') (range field=post_date ['2016-02-16T08:13:26Z','2016-09-16T08:13:26Z'}) (phrase field=name 'RIO'))
and the results seem OK.
I'm fairy new to CloudSearch, so i very likely have syntax errors, but i can't seem to find them. help?
You're using the phrase operator but not actually searching for a phrase; it would be best to use the term operator (or no operator) instead. I can't see why it should matter but using something outside of how it was intended to be used can invite unintended consequences.
Here is how I'd re-write your queries:
Using term (mainly just used if you want to boost fields):
(and (term field=parent_post_content 'BRAZIL') (range field=post_date ['2016-02-16T08:13:26Z','2016-09-16T08:13:26Z'}) (or (term field=title 'RIO') (term field=excerpt 'RIO')))
Without an operator (I find this simplest):
(and parent_post_content:'BRAZIL' (range field=post_date ['2016-02-16T08:13:26Z','2016-09-16T08:13:26Z'}) (or title:'RIO' excerpt:'RIO'))
If that fails, can you post the complete query? I'd like to check that, for example, you're using the structured query parser since you mentioned you're new to CloudSearch.
Here are some relevant docs from Amazon:
Compound queries for more on the various operators
Searching text for specifics on the phrase operator
Apparently the problem was not with the query, but with the displayed content. I foolishly trusted that the content displaying in the CloudSearch site was complete, and so concluded that it does not contain Brazil. But alas, it is not the full content, and when i check the full content, Brazil was there.
Sorry for the foolery.

Retrieve a document class-description symbolicName without fetching

I'm triying to retrieve a ClassDescription symbolicName of an IDocument object. It seems that i have to fetch its ClassDescription even if I just want the symbolicName.
Is there a way to do it ? I just want to avoid doing a fetch for every browsed document...
(Also IDocument.GetClassName doesn't help, it returns "Document")
I finally found a way, by making an SQL SELECT request retrieving the classDescription ID (which is not the symbolicName ID, but rather an "internal" one) :
Select This, d.Id, d.ClassDescription
From Document d
where d.Id = ID
It seems to be lighter than a line like document.fetch(classDescription) (pseudo call) cause it should just retrieves the ID.
I thought it worth mentioning a problem regarding the accepted answer.
There are times that doing a query would be "lighter" however I believe you are missing something involving fetching a document.
FileNet's fetchInstance command can take in a PropertyFilter.
In your case you could do something along the lines of:
PropertyFilter pf = new PropertyFilter();
pf.AddIncludeProperty(new FilterElement(null, null, null, "ClassDescription", null));
doc = Factory.Document.FetchInstance(os, new Id("doc.ID()"), pf);
You would probably want to look at your original fetch of this document and make sure to specify the full list of property filters at that point.
See Working With Documents

read all document by using particular category name using alfresco search.luceneSearch or search.lib.js

Category Name
|
Geograpy (8)
Study Db (18)
i am implement my own advance search in alfresco. i need to read all files which related with particular category.
example:
if there is 20 file under geograpy, lucene query should read particular document under search key word "banana".
Further explanation -
I am using search.lib.js to search. I would like to analyze the result to find out to which category the documents belong to. For example I would like to know how many documents belong to the category under Languages and the subcategories. I experimented with the Classification API but I don't get the result I want. Any Idea how to go through the result to get the category name of each document?
is there any simple method like node.properties["cm:creator"]?
thanks
janaka
I think you should specify more your question:
Are you using cm:content or a customized content?
Are you going to search the keyword inside the content of the file? or are you going to search the keyword in a specific metadata(s)?
Do you want to create a webscript (java or javascript)?
One thing to take in consideration:
if you use +PATH:"cm:generalclassifiable/...." for the categorization in your lucene queries, the performance will be slow (following my experince)
You can use for example the next query to find all nodes at any depth below /cm:Languages:
var results = search.luceneSearch("+PATH:\"cm:generalclassifiable/cm:Languages//*\");
Take a look to this url: https://wiki.alfresco.com/wiki/Search#Path_Queries
Once you have all the elements, you can loop all, and get to which category below. Of course you need to create some counter per each category/subcategory:
for(i = 0; i < results.length; i++){
var node = results[i];
var categoryNodeRef = node.properties["cm:categories"];
var categoryDesc = categoryNodeRef.properties["cm:description"];
var categoryName = categoryNodeRef.properties["cm:name"];
}
This is not exactly the solution, but can be a useful idea to start.
Sorry if it's not what you're asking for, I have just arrived from my holidays.

Detailed information in Lucene/Solr results

After having performed a search in Lucene/Solr without having specified a field, how can I know in which fields of a result document the search string was found (and how often)?
You could use Query Highlighting.
Try setting debugQuery=on. See this example.
As mentioned, use debugQuery=true. The response will then include an "explain" section. By default, this will give you some awful formatted text that looks like this:
0.69102794 = (MATCH) weight(body:arrai^1.5 in 6357), product of:
0.46610788 = queryWeight(body:arrai^1.5), product of:
1.5 = boost
5.591044 = idf(docFreq=55709, maxDocs=5492855)
0.055577915 = queryNorm
1.4825494 = (MATCH) fieldWeight(body:arrai in 6357), product of:
2.828427 = tf(termFreq(body:arrai)=8)
5.591044 = idf(docFreq=55709, maxDocs=5492855)
0.09375 = fieldNorm(field=body, doc=6357)
For each match in each field, you will get a block like this that explains how SOLR computed the relevancy of this document to your query. What you're asking about (how many matches in this document's field) SOLR calls term frequency "tf". You can see this on the 7th line of the output i pasted above. In this line, SOLR is telling you that it found 8 matches for arrai in the field called "body".
The other lines stand for things like inverse document frequency-"idf" (how rare the matched term is) and fieldNorm, which relates to how short the document's field is relative to the match. You can learn about these here: http://wiki.apache.org/solr/SolrRelevancyFAQ
FYI if you need this "explain" information in a structured format instead of clumsy text you can pass this parameter with your query: debug.explain.structured=true However, its still pretty hard to use = )