I have data in ES which looks like this:
'{"Emp_ID":"12212","Emp_Name":"Jim","Emp_Sal":300,"Dep_Id":22,"Dep_Name":"IT","Dep_Cnt":40}'
'{"Emp_ID":"6874590","Emp_Name":"Joe","Emp_Sal":140,"Dep_Id":66,"Dep_Name":"Admin","Dep_Cnt":20}'
'{"Emp_ID":"32135","Emp_Name":"Jill","Emp_Sal":170,"Dep_Id":66,"Dep_Name":"Admin","Dep_Cnt":20}'
'{"Emp_ID":"43312","Emp_Name":"Andy","Emp_Sal":450,"Dep_Id":22,"Dep_Name":"IT","Dep_Cnt":40}'
'{"Emp_ID":"315609","Emp_Name":"Cody","Emp_Sal":150,"Dep_Id":22,"Dep_Name":"IT","Dep_Cnt":40}'
'{"Emp_ID":"87346","Emp_Name":"Dave","Emp_Sal":500,"Dep_Id":55,"Dep_Name":"hr","Dep_Cnt":10}'
I want to get all the unique departments ordered by Dep_Cnt, for which I wrote the following query
{
"size":0,
"aggs":{
"by_Dep_Cnt":{
"terms":{
"field":"Dep_Cnt",
"order":{
"_term":"asc"
}
},
"aggs":{
"by_unique_dep_id":{
"terms":{
"field":"Dep_Id"
},
"aggs":{
"tops":{
"top_hits":{
"size":1
}
}
}
}
}
}
}
}
And got expected output of 3 unique departments ordered by Dep_Cnt.
But now my requirement is to get only the top two departments.
How do I modify the query to get only 2 buckets?
What you are looking for is the parameter size of the terms aggregation:
If Dep_Cnt is the number of employees in your department and your document are per employee and you have all the employee in your index (from your mapping it may be the case) you can just do:
{
"size":0,
"aggs":{
"by_Dep_Id":{
"terms":{
"field":"Dep_Id",
"size": 2
}
}
}
Since by default it will sort by the number of documents with the corresponding value i.e. the number of documents with this Dep_Id i.e. the number of employees in this department.
If you are not in this situation:
Your current request does not behave the same way when you have two department with the same size (you will have two Dep_Ids in the same bucket of Dep_Cnt)
You can group documents by Dep_Id, get the Dep_Cnt using the metric you want (min, max, avg, ...) and sort on this metric:
{
"size":0,
"aggs":{
"by_Dep_Id":{
"terms":{
"field":"Dep_Id",
"size": 2
"order":{
"avg_Dep_Cnt":"asc"
}
},
"aggs":{
"avg_Dep_Cnt":{
"avg":{
"field":"Dep_Cnt"
}
}
}
}
}
}
NB: I removed the top_hits aggregations since you do not need them according to what you explained, if you have extra requirement just add them in the aggregation.
Related
I'm using Elasticsearch 6. I want to calculate sales differences (grouped by categories) across 2 date ranges and sort it afterwards.
In the example query below, I used Bucket Script aggregation to evaluate the sales differences before sorting it with Bucket Sort aggregation to obtain the top 10 largest sales difference.
{
"size":0,
"aggs":{
"categories":{
"terms":{
"field":"category"
},
"aggs":{
"months_range":{
"date_range":{
"field":"date",
"ranges":[
{ "from":"01-2015", "to":"03-2015", "key":"start_month" },
{ "from":"03-2015", "to":"06-2015", "key":"end_month" }
],
"keyed":true
},
"aggs":{
"sales":{
"sum":{
"field":"sales_amount"
}
}
}
},
"sales_difference":{
"bucket_script":{
"buckets_path":{
"startMonthSales":"months_range.start_month>sales", // correct syntax?
"endMonthSales":"months_range.end_month>sales" // correct syntax?
},
"script":"params.endMonthSales - params.startMonthSales"
}
},
"sales_bucket_sort":{
"bucket_sort":{
"sort":[
{
"sales_difference":{
"order":"desc"
}
}
],
"size":10
}
}
}
}
}
}
My questions:
Is my bucket path's syntax correct? Is it possible to access individual date_range bucket, e.g. months_range.end_month, in the bucket path?
How's the performance of executing a custom script in Elasticsearch as compared to running similar business logic in the application server?
I use this query to get search hits and the count of hits across multiple indices:
/index1,index2/_search
{
"query":{
"query_string":{
"query":"*"
}
},
"aggs":{
"group_by_index":{
"terms":{
"field":"_index",
"min_doc_count":0
}
}
},
"post_filter":{
"terms":{
"_index":"index1"
}
},
"sort":{
"my_field":"asc"
}
}
The problem is if I sort on a field (my_field) that only exist in index1, the aggregation will only give me the hits count of index1, and not index2.
I thought the aggregation would work regardless of what sorting I have specified?
Using Elasticsearch 6.4
Solved it by using unmapped_type
I have Elastic search v6.5 with an index of 300 million documents.
Documents field type keyword, example {"url": "http:/linkedin.com/435"}.
{
"size":0,
"aggs":{
"duplicateCount":{
"terms":{
"field":"url",
"min_doc_count":2
}
}
}
}
I got 0 results, then posted test_url value 2 times to the URL again, launched the query and it remains an empty set. What is the reason and is
there any way to overcome the issue?
{
"size":0,
"aggs":{
"duplicateCount":{
"terms":{
"field":"url.keyword",
"min_doc_count":2
}
}
}
}
You need to add .keyword at the end of field name.
Try this. Hope this will work.
I have the following query:
GET images/_search
{
"query":{
"bool":{
"must":[
{
"term":{
"appID.raw":"myApp"
}
}
]
}
},
"size":0,
"aggs":{
"perDeviceAggregation":{
"terms":{
"field":"deviceID",
"min_doc_count":50000
}
}
}
}
This query returns a "buckets" array, but I would like to return only the length of the array, without the array itself.
Explanation: the purpose of this query is to count how many devices that belong to app "myApp", have over 50,000 images. I don't need the query to return these devices, just to know how many are there.
The terms aggregation returns buckets -- 1 bucket for each unique term of the field -- where each bucket contains the count of documents that contain the term.
It sounds like you want to know the number of unique terms instead of the document count per term. This concept is called cardinality.
There is a different aggregation to determine cardinality. Your query would look like this:
GET images/_search
{
"query":{
"bool":{
"must":[
{
"term":{
"appID.raw":"myApp"
}
}
]
}
},
"size":0,
"aggs":{
"deviceIdCardinality":{
"cardinality":{
"field":"deviceID"
}
}
}
}
NOTE: cardinality counts are approximate. You can configure the accuracy with the precision_threshold parameter to the aggregation. See the documentation for specifics.
i am planning to implement a query for calculating the bounce rate using elasticsearch query.
can any body know how to use the input of aggreation results using script ?
{
"aggs":{
"monthly":{
"date_histogram":{
"field":"timestamp",
"interval":"month",
"script":""
},
"aggs":{
"visits_greater_than_one":{
"terms":{
"field":"sessionId",
"min_doc_count":2
}
}
},
"aggs":{
"visitor_count":{
"cardinality":{
"field":"sessionId"
}
}
}
}
}
}
Thanks,
Ankireddy Polu
i have found a little workaround for addressing this problem
{
"aggs":{
"monthly":{
"date_histogram":{
"field":"timestamp",
"interval":"month"
},
"aggs":{
"visits_greater_than_one":{
"terms":{
"field":"sessionId",
"min_doc_count":2
}
},
"visitor_count":{
"cardinality":{
"field":"sessionId"
}
}
}
}
}
}
the drawback with the approach is we need to perform the calculation separately where ever we pares the result, we will have a two different buckets one will hold the number of sessions whose have more than one entry and total number of session during that interval. using that (visitor_count - visits_greater_than_one)/visitor_count will be my bounce rate
(visitor_count - visits_greater_than_one) gives me the sessions user visited only single page