Say I have a filter in query like this:
{
"query" : {
"filtered" : {
"filter" : {
"term" : {
"price" : 20
}
}
}
}
}
According to the official doc, there will be a filter cache associated to the key "price".
One day, I change the query as follow:
{
"query" : {
"filtered" : {
"filter" : {
"term" : {
"price" : 20,
"_cache" : false
}
}
}
}
}
Will Elasticsearch automatically remove the exist cache?
Not really sure. It will probably be removed eventually but probably not immediately. It doesn't really matter however as setting _cache = false will tell elastic search to not use the cache even if it is technically still there. If you want to clear the cache manually there's an API for it.
Here is an example:curl -XPOST 'http://localhost:9200/twitter/_cache/clear
https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-clearcache.html
Related
I am getting the results based on various filters in the Elasticsearch which also includes pagination.
Now I need to navigate between previous and next record from that search results, when we open a record of the search results.
Is there a way to achieve this through Elasticsearch?
You could use the from and size parameters of the Search API.
GET /_search
{
"from" : 0, "size" : 10,
"query" : {
"term" : { "user" : "kimchy" }
}
}
or
GET /_search?from=0&size=10
{
"query" : {
"term" : { "user" : "kimchy" }
}
}
Note the default value for size is 10.
I am using terms aggregation on elasticsearch to get most used words in a index with 380607390 (380 millions) and i receive timeout on my application.
The aggregated field is a text with a simple analyzer( the field holds post content).
My question is:
The terms aggregation is the correct aggregation to do that? With a large content field?
{
"aggs" : {
"keywords" : {
"terms" : { "field" : "post_content" }
}
}
}
You can try this using min_doc_count. You would ofcourse not want to get those words which have been used just once or twice or thrice...
You can set min_doc_count as per your requirement. This would definitely
reduce the time.
{
"aggs" : {
"keywords" : {
"terms" : { "field" : "post_content",
"min_doc_count": 5 //----->Set it as per your need
}
}
}
}
For my project, I thought of using Span Near Queries of ElasticSearch, with the constraint that is, certain tokens may have to searched with Fuzziness. I was able to generate a set of SpanQuery (org.apache.lucene.search.spans.SpanQuery) objects some with fuzzy enabled, some without. I couldn't figure out how to use these set of SpanQueries in ElasticSearch spanNearQuery.
Can someone help me out with right pointers to samples or docs. And is there any way to construct ES SpanNearQueryBuilder with some clauses fuzzy enabled ?
You can wrap an fuzzy query into a span query with Span Multi Term Query:
{
"span_near" : {
"clauses" : [
{ "span_term" : { "field" : "value1" } },
{ "span_multi" :
"match" : {
"prefix" : { "user" : { "field" : "value2" } }
}
}
],
...
}
}
I'm adding a field to a doc like this:
curl -XPOST 'http://localhost:9200/imap_email/imap_bruce/12/_update' -d '{
"script" : "ctx._source.simperium = \"12345\""
}'
Looking at that doc, I can verify that it has added the field "simperium". The following query (and the many variations of it I've tried) simply return everything in my index.
{
"constant_score" : {
"filter" : {
"exists" : { "field" : "simperium" }
}
}
}
What do I need to do to get a strict list of all docs that do or don't have a specific field?
The majority of Elasitcsearch examples exclude the outer "query" : {} object for brevity. It's very annoying when starting out, but eventually you learn to accept it.
You most likely wanted this:
{
"query" : {
"constant_score" : {
"filter" : {
"exists" : { "field" : "simperium" }
}
}
}
}
i have logs like:
{
"a":"XXX",
"b":"YYY",
"token":"acquired"
}
Also, i have logs that do not have this token key set. Kibana's terms panel tells that they are around by showing them as Missing fields(3047). How can i query all docs that do not have the token key set?
You can query in ES for missing fields:
From: http://www.elasticsearch.org/guide/en/elasticsearch/guide/current/_dealing_with_null_values.html
GET /my_index/posts/_search
{
"query" : {
"filtered" : {
"filter": {
"missing" : { "field" : "token" }
}
}
}
}