How can I get the list of terms that elasticsearch matched in each result? I know the highlight contains this but I want to get a list of the terms that were found without manually performing postprocessing on the highlight for each result.
You could use named queries with unique query for each term.
Search result will contain matched queries for each document in result.
Related
Being new to ElasticSearch, need help in my understanding.
What I read about term vs match query is that term query is used for exact match and match query is used when we are searching for a term and want result based on a relevancy score.
But if we already defined a mapping for a field as a keyword, why anyone has to decide upon between term vs match, wouldn't it be always a term query in case mapping is defined as a keyword?
What are the use cases where someone will make a match query on the keyword mapping field?
The same confusion is vice versa.
A text field will be analyzed (transformed, split) to generate N tokens, and the keyword itself will become a token with no transformations. At the end, you have N tokens referencing a document.
Then.
By doing a match query, you will treat your query as a text as well, by analyzing it before performing the matching (transforming it), and the term will not.
You can create a field with a term mapping, but then perform a match query on top of it (for example if you want to be case insensitive), and you can create a text mapping for a n-gram and perform a term query to match exactly what you're asking for.
Im tring to understand the DSL query i needed if i want to make a search from a result set i got. means i have an initial term search, then i want make another query upon the previous result.
lets say i a have 10 documents with a sharing identifier between them, each document has a description field. i want to search first all the documents containing the value 'Hello' in the description and then take their id's, and search the document containing the value 'good by'.
thanks.
No need to execute two queries, you can use filter context that will filter out the results.filter parameter will filter out documents that do not match, and will also not affect the score for matching documents.
Filter context is in effect whenever a query clause is passed to a
filter parameter, such as the filter or must_not parameters in the
bool query, the filter parameter in the constant_score query, or the
filter aggregation.
Refer this to know more about Query and Filter contexts
1.Having the next list of filter queries I would like to get some result documents basing on them
filter queries
fq=(name_text_en_us:"microwave") & fq=(name_text_en_us:"with") & fq=(name_text_en_us:"sensor")
Full url:
http://localhost:8983/solr/master/select?_=15231231220790&fq=name_text_en_us:"microwave"&fq=name_text_en_us:"with"&fq=name_text_en_us:"sensor"&indent=on&q=*:*&wt=json
I'm getting empty result.
Unfortunately I can't merge all queries in one and have to use them in a separate way.
2. I understand that since one of the filter queries consists only from a stopword - i.e. word "with" it will be parsed by SOLR as an empty string and basing on that SOLR will filter out all documents and result will be empty.
If I remove such query and leave other - SOLR returns several documents.
If there any way how I can configure SOLR to not take into account filter queries with stopwords and as a result after those get parsed and become an empty string.
In other words I would like SOLR to skip filter queries with empty string and return result basing on other from the list
I am trying to find a way that I can boost the search results for a particular query such that the search results that have the query at the beginning of the field (i.e. starts with) are above the results that do not.
e.g. Suppose my query is for 'bat'
I want my results to look like
bat
bath
bathe
abate
debate
etc.
You could try adding a prefix query with a boost value to make the score for prefix matches higher than the rest of the items.
We use ElasticSearch in a reverse manner from what I usually see. We store lots of small documents, usually 1 or 2 words, for example, Job Titles like "software engineering", "car mechanics", "architect", etc.
Then we query with a longer string, for example a 1000 word Job Spec. This way we get all Job Titles present in the text of the Job Spec.
It works well. But I was wondering whether I could get ElasticSearch to highlight the matching Job Titles in the Job Spec, i.e. highlight the results in the query. I have tried the highlight keyword, but it doesn't highlight the query text, it highlights the results. I'm not sure how to get the query to be returned in the ElasticSearch response, let alone whether it can be highlighted.
You might wonder why I need ElasticSearch to highlight the query, can't I just pick out all the results from the text and highlight them myself? Yes I can, but there's various things to think about that makes it hard such as stemming and stopword removal. for example "jquery" is stemmed to "jqueri" when doing the tokenising in ElasticSearch, so it's found as a result, but if I want to highlight it myself, I have to unstem it so it matches the original text. Elasticsearch also removes symbols, so terms & conditions would become terms conditions which is problematic if I want to highlight it manually as I have to add back the "&" symbol. There's a hundred other problem cases, hence the question about whether ElasticSearch can do it for me.
I'm quite sure highlighting the query string isn't possible - only highlighting parts of documents in an index.
What you might try is indexing the query string itself in it's own index and then using the results of the first query as the query terms for a second query against the query string (in the second index). You could then have highlighting on the query string. You'll have to make an extra request to ES each time, but I think it'll get what you want.