I am using Elasticsearch with a EdgeNGram filter which is set as follows:
"edgeNGram": {
"type": "edgeNGram",
"min_gram": 3,
"max_gram": 15,
},
The problem is that when I make a query using very short words, they are completely omitted from the search. Let's say I type in "Vitamin C" -> this gives me results for the first term "Vitamin" only. Is there any way how to tell Elasticsearch not to use EdgeNGram filter when indexing words up to 3 characters?
Thank you.
EDIT:
These are my settings:
ELASTICSEARCH_INDEX_SETTINGS = {
"settings": {
"analysis": {
"analyzer": {
"sk_hunspell": {
"type": "custom",
"tokenizer": "standard",
"filter": [
"sk_lowercase", "sk_SK", "stopwords_SK",
"edgeNGram", "asciifolding",
"remove_duplicities",
]
},
},
"filter": {
"sk_SK": {
"type": "hunspell",
"locale": "sk_SK",
"dedup": True,
"recursion_level": 0,
"ignore_case": True,
},
"sk_lowercase": {
"type": "lowercase",
},
"stopwords_SK": {
"type": "stop",
"stopwords": STOPWORDS_SK,
},
"remove_duplicities": {
"type": "unique",
"only_on_same_position": True
},
"edgeNGram": {
"type": "edgeNGram",
"min_gram": 3,
"max_gram": 15,
"token_chars": ["letter", "digit"],
},
},
}
}
}
In the database I store information about vitamins, minerals and medicinal plants. (Their use, collecting, blooming, health benefits etc.) The information are written in Slovak. (The names of the plants and minerals are also stored in Czech and Latin).
This idea may be a hack but you could pad words less than 3 with a special charecter before inserting them into the index so they are length 3.
When you accept the user's query you would have to also pad their words less than three with the same special charecter.
You would need to create a custom tokenizer for this.
Related
I have a problem indexing an array in Azure Cosmos DB
I am trying to save this indexing policy via the portal
{
"indexingMode": "consistent",
"automatic": true,
"includedPaths": [
{
"path": "/*"
}
],
"excludedPaths": [
{
"path": "/\"_etag\"/?"
}
],
"compositeIndexes": [
[
{
"path": "/DeviceId",
"order": "ascending"
},
{
"path": "/TimeStamp",
"order": "ascending"
},
{
"path": "/Items/[]/Name/?",
"order": "ascending"
},
{
"path": "/Items/[]/DoubleValue/?",
"order": "ascending"
}
]
]
}
I get the error "Failed to update container DeviceEvents:
Message: {"code":"BadRequest","message":"Message: {"Errors":["The indexing path '\/Items\/[]\/Name\/?' could not be accepted, failed near position '8'."
This seems to be the array [] syntax that is giving an error.
On a side note I am not sure what I am doing makes sense at all but I have a query that looks like this
SELECT SUM(de0["DoubleValue"])
FROM root JOIN de0 IN root["Items"]
WHERE root["ApplicationId"] = 57 AND root["DeviceId"] = 126 AND root["TimeStamp"] >= "2021-02-21T17:55:29.7389397Z" AND de0["Name"] = "Use Case"
Where ApplicationId is the partition key and the item saved looks like this
{
"id": "59ab9323-26ca-436f-8d29-e1ddd826f025",
"DeviceId": 3,
"ApplicationId": 3,
"RawData": "640F7A000A00E30142000000",
"TimeStamp": "2021-02-20T18:36:52.833174Z",
"Items": [
{
"Name": "Battery Status",
"StringValue": "Full",
"DoubleValue": null
},
{
"Name": "Use Case",
"StringValue": null,
"DoubleValue": 12
},
{
"Name": "Battery Voltage",
"StringValue": null,
"DoubleValue": 3.962
},
{
"Name": "Rain Gauge Count",
"StringValue": null,
"DoubleValue": 10
}
],
"_rid": "CgdVAO7B0DNkAAAAAAAAAA==",
"_self": "dbs/CgdVAA==/colls/CgdVAO7B0DM=/docs/CgdVAO7B0DNkAAAAAAAAAA==/",
"_etag": "\"61008771-0000-0d00-0000-603156c50000\"",
"_attachments": "attachments/",
"_ts": 1613846213
}
I need to aggregate on some of these items in the array like say get MAX on temperature or something like this (using Use Case for test although it doesn't make sense). I reasoned that if all the data in the query is in a single composite index the database would be able to do the aggregation without reading the documents themselves. However I can't seem to add a composite index containing an array at all.
Yes, composite index can't contain an array path. It should be a scalar value.
Unlike with included or excluded paths, you can't create a path with
the /* wildcard. Every composite path has an implicit /? at the end of
the path that you don't need to specify. Composite paths lead to a
scalar value and this is the only value that is included in the
composite index.
Reference:https://learn.microsoft.com/en-us/azure/cosmos-db/index-policy#composite-indexes
I am doing tests with elastic search in indexing wikipedia's topics.
Below my settings.
Results I expect is to have first result matching the exact string - especially if string is made by one word only.
Instead:
Searching for "g"
curl "http://localhost:9200/my_index/_search?q=name:g&pretty=True"
returns
[Changgyeonggung, Lopadotemachoselachogaleokranioleipsanodrimhypotrimmatosilphioparaomelitokatakechymenokichlepikossyphophattoperisteralektryonoptekephalliokigklopeleiolagoiosiraiobaphetraganopterygon, ..] as first results (yes, serendipity time! that is a greek dish if you are curious [http://nifty.works/about/BgdKMmwV6B3r4pXJ/] :)
I thought because the results weight more "G" letters respect to other words.. but:
Searching for "google":
curl "http://localhost:9200/my_index/_search?q=name:google&pretty=True"
returns
[Googlewhack, IGoogle, Google+, Google, ..] as first results, and I would expect Google to be the first.
What is wrong in my settings for not hitting exact keyword if exists?
I used index and search analyzers for the reason suggested in this answer:[https://stackoverflow.com/a/15932838/305883]
Settings
# make index with mapping
curl -X PUT localhost:9200/test-ngram -d '
{
"settings": {
"analysis": {
"analyzer": {
"index_analyzer": {
"type" : "custom",
"tokenizer": "lowercase",
"filter": ["asciifolding", "title_ngram"]
},
"search_analyzer": {
"type": "custom",
"tokenizer": "standard",
"filter": ["standard", "lowercase", "stop", "asciifolding"]
}
},
"filter": {
"title_ngram" : {
"type" : "nGram",
"min_gram" : 1,
"max_gram" : 10
}
}
}
},
"mappings": {
"topic": {
"properties": {
"name": {
"type": "string",
"boost": 10.0,
"index": "analyzed",
"index_analyzer": "index_analyzer",
"search_analyzer": "search_analyzer"
}
}
}
}
}
'
That's because relevance works in a different way by default (check the part about TF/IDF
https://www.elastic.co/guide/en/elasticsearch/guide/current/relevance-intro.html)
If you want to have exact term match on the top of the results while also matching substrings etc, you need to index name as multifield like this:
"name": {
"type": "string",
"index": "analyzed",
// other analyzer stuff here
"fields": {
"raw": { "type": "string", "index": "not_analyzed" }
}
}
Then in the boolean query you need to query both name and name.raw and boost results from name.raw
I am using the suggestion api within ES with completion. My implementation works (code below) but I would like to search for multiple words within a query. In the example below if I query search "word" it finds "wordpress" and outputs "Found". What I am am trying to accomplish is querying with something like "word blog magazine" which are all tags and have an output of "Found". Any help would be appreciated!
Mapping:
curl -XPUT "http://localhost:9200/test_index/" -d'
{
"mappings": {
"product": {
"properties": {
"description": {
"type": "string"
},
"tags": {
"type": "string"
},
"title": {
"type": "string"
},
"tag_suggest": {
"type": "completion",
"index_analyzer": "simple",
"search_analyzer": "simple",
"payloads": false
}
}
}
}
}'
Add document:
curl -XPUT "http://localhost:9200/test_index/product/1" -d'
{
"title": "Product1",
"description": "Product1 Description",
"tags": [
"blog",
"magazine",
"responsive",
"two columns",
"wordpress"
],
"tag_suggest": {
"input": [
"blog",
"magazine",
"responsive",
"two columns",
"wordpress"
],
"output": "Found"
}
}'
_suggest query:
curl -XPOST "http://localhost:9200/test_index/_suggest" -d'
{
"product_suggest":{
"text":"word",
"completion": {
"field" : "tag_suggest"
}
}
}'
The results are as we would expect:
{
"_shards": {
"total": 1,
"successful": 1,
"failed": 0
},
"product_suggest": [
{
"text": "word",
"offset": 0,
"length": 4,
"options": [
{
"text": "Found",
"score": 1
},
]
}
]
}
If you're willing to switch to using edge ngrams (or full ngrams if you need them), I think it will solve your problem.
I wrote up a pretty detailed explanation of how to do this in this blog post:
https://qbox.io/blog/an-introduction-to-ngrams-in-elasticsearch
But I'll give you a quick and dirty version here. The trick is to use ngrams together with the _all field and the match AND operator.
So with this mapping:
PUT /test_index
{
"settings": {
"analysis": {
"filter": {
"ngram_filter": {
"type": "edge_ngram",
"min_gram": 2,
"max_gram": 20
}
},
"analyzer": {
"ngram_analyzer": {
"type": "custom",
"tokenizer": "standard",
"filter": [
"lowercase",
"ngram_filter"
]
}
}
}
},
"mappings": {
"doc": {
"_all": {
"type": "string",
"analyzer": "ngram_analyzer",
"search_analyzer": "standard"
},
"properties": {
"word": {
"type": "string",
"include_in_all": true
},
"definition": {
"type": "string",
"include_in_all": true
}
}
}
}
}
and some documents:
PUT /test_index/_bulk
{"index":{"_index":"test_index","_type":"doc","_id":1}}
{"word":"democracy", "definition":"government by the people; a form of government in which the supreme power is vested in the people and exercised directly by them or by their elected agents under a free electoral system."}
{"index":{"_index":"test_index","_type":"doc","_id":2}}
{"word":"republic", "definition":"a state in which the supreme power rests in the body of citizens entitled to vote and is exercised by representatives chosen directly or indirectly by them."}
{"index":{"_index":"test_index","_type":"doc","_id":3}}
{"word":"oligarchy", "definition":"a form of government in which all power is vested in a few persons or in a dominant class or clique; government by the few."}
{"index":{"_index":"test_index","_type":"doc","_id":4}}
{"word":"plutocracy", "definition":"the rule or power of wealth or of the wealthy."}
{"index":{"_index":"test_index","_type":"doc","_id":5}}
{"word":"theocracy", "definition":"a form of government in which God or a deity is recognized as the supreme civil ruler, the God's or deity's laws being interpreted by the ecclesiastical authorities."}
{"index":{"_index":"test_index","_type":"doc","_id":6}}
{"word":"monarchy", "definition":"a state or nation in which the supreme power is actually or nominally lodged in a monarch."}
{"index":{"_index":"test_index","_type":"doc","_id":7}}
{"word":"capitalism", "definition":"an economic system in which investment in and ownership of the means of production, distribution, and exchange of wealth is made and maintained chiefly by private individuals or corporations, especially as contrasted to cooperatively or state-owned means of wealth."}
{"index":{"_index":"test_index","_type":"doc","_id":8}}
{"word":"socialism", "definition":"a theory or system of social organization that advocates the vesting of the ownership and control of the means of production and distribution, of capital, land, etc., in the community as a whole."}
{"index":{"_index":"test_index","_type":"doc","_id":9}}
{"word":"communism", "definition":"a theory or system of social organization based on the holding of all property in common, actual ownership being ascribed to the community as a whole or to the state."}
{"index":{"_index":"test_index","_type":"doc","_id":10}}
{"word":"feudalism", "definition":"the feudal system, or its principles and practices."}
{"index":{"_index":"test_index","_type":"doc","_id":11}}
{"word":"monopoly", "definition":"exclusive control of a commodity or service in a particular market, or a control that makes possible the manipulation of prices."}
{"index":{"_index":"test_index","_type":"doc","_id":12}}
{"word":"oligopoly", "definition":"the market condition that exists when there are few sellers, as a result of which they can greatly influence price and other market factors."}
I can apply partial matching across both fields (would work with as many fields as you want) like this:
POST /test_index/_search
{
"query": {
"match": {
"_all": {
"query": "theo go",
"operator": "and"
}
}
}
}
which in this case, returns:
{
"took": 2,
"timed_out": false,
"_shards": {
"total": 1,
"successful": 1,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 0.7601639,
"hits": [
{
"_index": "test_index",
"_type": "doc",
"_id": "5",
"_score": 0.7601639,
"_source": {
"word": "theocracy",
"definition": "a form of government in which God or a deity is recognized as the supreme civil ruler, the God's or deity's laws being interpreted by the ecclesiastical authorities."
}
}
]
}
}
Here is the code I used here (there's more in the blog post):
http://sense.qbox.io/gist/e4093c25a8257499f54ced5a09f35b1eb48e4e3c
Hope that helps.
In the elasticsearch module I have built, is it possible to return the "input search term" in the search results ?
For example :
GET /signals/_search
{
"query": {
"match": {
"focused_content": "stock"
}
}
}
This returns
{
"took": 2,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 1,
"max_score": 0.057534903,
"hits": [
{
"_index": "signals",
"_type": "signal",
"_id": "13",
"_score": 0.057534903,
"_source": {
"username": "abc#abc.com",
"tags": [
"News"
],
"content_url": "http://www.wallstreetscope.com/morning-stock-highlights-western-digital-corporation-wdc-fibria-celulose-sa-fbr-ametek-inc-ame-cott-corporation-cot-graftech-international-ltd-gti/25375462/",
"source": null,
"focused_content": "Morning Stock Highlights: Western Digital Corporation (WDC), Fibria Celulose SA (FBR), Ametek Inc. (AME), Cott Corporation (COT), GrafTech International Ltd. (GTI) - WallStreet Scope",
"time_stamp": "2015-08-12"
}
}
]
}
Is it possible to have the input search term "stock" along with each of the results (like an additional JSON Key along with "content_url","source","focused_content","time_stamp") to identify which search term had brought that result ?
Thanks in Advance !
All I can think of, would be using highlighting feature. So it would bring back additional key _highlightand it would highlight things, that matched.
It won't bring exact matching terms, tho. You'd have to deal with them in your application. You could use pre/post tags functionality to wrap them up somehow specially, so your app could recognize that it was a match.
You can use highlights on all fields, like #Evaldas suggested. This will return the result along with the value in the field which matched, surrounded by customisable tags (default is <em>).
GET /signals/_search
{
"highlight": {
"fields": {
"username": {},
"tags": {},
"source": {},
"focused_content": {},
"time_stamp": {}
}
},
"query": {
"match": {
"focused_content": "stock"
}
}
}
I think it's best if I describe my intent and try to break it down to code.
I want users to have the ability of complex queries should they choose to that query_string offers. For example 'AND' and 'OR' and '~', etc.
I want to have fuzziness in effect, which has made me do things I feel dirty about like "#{query}~" to the sent to ES, in other words I am specifying fuzzy query on the user's behalf because we offer transliteration which could be difficult to get the exact spelling.
At times, users search a number of words that are suppose to be in a phrase. query_string searches them individually and not as a phrase. For example 'he who will' should bring me the top match to be when those three words are in that order, then give me whatever later.
Current query:
{
"indices_boost": {},
"aggregations": {
"by_ayah_key": {
"terms": {
"field": "ayah.ayah_key",
"size": 6236,
"order": {
"average_score": "desc"
}
},
"aggregations": {
"match": {
"top_hits": {
"highlight": {
"fields": {
"text": {
"type": "fvh",
"matched_fields": [
"text.root",
"text.stem_clean",
"text.lemma_clean",
"text.stemmed",
"text"
],
"number_of_fragments": 0
}
},
"tags_schema": "styled"
},
"sort": [
{
"_score": {
"order": "desc"
}
}
],
"_source": {
"include": [
"text",
"resource.*",
"language.*"
]
},
"size": 5
}
},
"average_score": {
"avg": {
"script": "_score"
}
}
}
}
},
"from": 0,
"size": 0,
"_source": [
"text",
"resource.*",
"language.*"
],
"query": {
"bool": {
"must": [
{
"query_string": {
"query": "inna alatheena",
"fuzziness": 1,
"fields": [
"text^1.6",
"text.stemmed"
],
"minimum_should_match": "85%"
}
}
],
"should": [
{
"match": {
"text": {
"query": "inna alatheena",
"type": "phrase"
}
}
}
]
}
}
}
Note: alatheena searched without the ~ will not return anything although I have allatheena in the indices. So I must do a fuzzy search.
Any thoughts?
I see that you're doing ES indexing of Qur'anic verses, +1 ...
Much of your problem domain, if I understood it correctly, can be solved simply by storing lots of transliteration variants (and permutations of their combining) in a separate field on your Aayah documents.
First off, you should make a char filter that replaces all double letters with single letters [aa] => [a], [ll] => [l]
Maybe also make a separate field containing all of [a, e, i] (because of their "vocative"/transcribal ambiguity) replaced with € or something similar, and do the same while querying in order to get as many matches as possible...
Also, TH in "allatheena" (which as a footnote may really be Dhaal, Thaa, Zhaa, Taa+Haa, Taa+Hhaa, Ttaa+Hhaa transcribed ...) should be replaced by something, or both the Dhaal AND the Thaa should be transcribed multiple times.
Then, because it's Qur'anic script, all Alefs without diacritics, Hamza, Madda, etc should be treated as Alef (or Hamzat) ul-Wasl, and that should also be considered when indexing / searching, because of Waqf / Wasl in reading arabic. (consider all the Wasl`s in the first Aayah of Surat Al-Alaq for example)
Dunno if this is answering your question in any way, but I hope it's of some assistance in implementing your application nontheless.
You should use Dis Max Query to achieve that.
A query that generates the union of documents produced by its
subqueries, and that scores each document with the maximum score for
that document as produced by any subquery, plus a tie breaking
increment for any additional matching subqueries.
This is useful when searching for a word in multiple fields with
different boost factors (so that the fields cannot be combined
equivalently into a single search field). We want the primary score to
be the one associated with the highest boost.
Quick example how to use it:
POST /_search
{
"query": {
"dis_max": {
"tie_breaker": 0.7,
"boost": 1.2,
"queries": [
{
"match": {
"text": {
"query": "inna alatheena",
"type": "phrase",
"boost": 5
}
}
},
{
"match": {
"text": {
"query": "inna alatheena",
"type": "phrase",
"fuzziness": "AUTO",
"boost": 3
}
}
},
{
"query_string": {
"default_field": "text",
"query": "inna alatheena"
}
}
]
}
}
}
It will run all of your queries, and the one, which scored highest compared to others, will be taken. So just define your rules using it. You should achieve what you wanted.