Children aggregation
editChildren aggregation
editA special single bucket aggregation that selects child documents that have the specified type, as defined in a join field.
This aggregation has a single option:
-
type- The child type that should be selected.
For example, let’s say we have an index of questions and answers. The answer type has the following join field in the mapping:
resp = client.indices.create(
index="child_example",
mappings={
"properties": {
"join": {
"type": "join",
"relations": {
"question": "answer"
}
}
}
},
)
print(resp)
response = client.indices.create(
index: 'child_example',
body: {
mappings: {
properties: {
join: {
type: 'join',
relations: {
question: 'answer'
}
}
}
}
}
)
puts response
const response = await client.indices.create({
index: "child_example",
mappings: {
properties: {
join: {
type: "join",
relations: {
question: "answer",
},
},
},
},
});
console.log(response);
PUT child_example
{
"mappings": {
"properties": {
"join": {
"type": "join",
"relations": {
"question": "answer"
}
}
}
}
}
The question document contain a tag field and the answer documents contain an owner field. With the children
aggregation the tag buckets can be mapped to the owner buckets in a single request even though the two fields exist in
two different kinds of documents.
An example of a question document:
resp = client.index(
index="child_example",
id="1",
document={
"join": {
"name": "question"
},
"body": "I have Windows 2003 server and i bought a new Windows 2008 server...",
"title": "Whats the best way to file transfer my site from server to a newer one?",
"tags": [
"windows-server-2003",
"windows-server-2008",
"file-transfer"
]
},
)
print(resp)
response = client.index(
index: 'child_example',
id: 1,
body: {
join: {
name: 'question'
},
body: 'I have Windows 2003 server and i bought a new Windows 2008 server...',
title: 'Whats the best way to file transfer my site from server to a newer one?',
tags: [
'windows-server-2003',
'windows-server-2008',
'file-transfer'
]
}
)
puts response
const response = await client.index({
index: "child_example",
id: 1,
document: {
join: {
name: "question",
},
body: "I have Windows 2003 server and i bought a new Windows 2008 server...",
title:
"Whats the best way to file transfer my site from server to a newer one?",
tags: ["windows-server-2003", "windows-server-2008", "file-transfer"],
},
});
console.log(response);
PUT child_example/_doc/1
{
"join": {
"name": "question"
},
"body": "<p>I have Windows 2003 server and i bought a new Windows 2008 server...",
"title": "Whats the best way to file transfer my site from server to a newer one?",
"tags": [
"windows-server-2003",
"windows-server-2008",
"file-transfer"
]
}
Examples of answer documents:
resp = client.index(
index="child_example",
id="2",
routing="1",
document={
"join": {
"name": "answer",
"parent": "1"
},
"owner": {
"location": "Norfolk, United Kingdom",
"display_name": "Sam",
"id": 48
},
"body": "Unfortunately you're pretty much limited to FTP...",
"creation_date": "2009-05-04T13:45:37.030"
},
)
print(resp)
resp1 = client.index(
index="child_example",
id="3",
routing="1",
refresh=True,
document={
"join": {
"name": "answer",
"parent": "1"
},
"owner": {
"location": "Norfolk, United Kingdom",
"display_name": "Troll",
"id": 49
},
"body": "Use Linux...",
"creation_date": "2009-05-05T13:45:37.030"
},
)
print(resp1)
response = client.index(
index: 'child_example',
id: 2,
routing: 1,
body: {
join: {
name: 'answer',
parent: '1'
},
owner: {
location: 'Norfolk, United Kingdom',
display_name: 'Sam',
id: 48
},
body: "Unfortunately you're pretty much limited to FTP...",
creation_date: '2009-05-04T13:45:37.030'
}
)
puts response
response = client.index(
index: 'child_example',
id: 3,
routing: 1,
refresh: true,
body: {
join: {
name: 'answer',
parent: '1'
},
owner: {
location: 'Norfolk, United Kingdom',
display_name: 'Troll',
id: 49
},
body: 'Use Linux...',
creation_date: '2009-05-05T13:45:37.030'
}
)
puts response
const response = await client.index({
index: "child_example",
id: 2,
routing: 1,
document: {
join: {
name: "answer",
parent: "1",
},
owner: {
location: "Norfolk, United Kingdom",
display_name: "Sam",
id: 48,
},
body: "Unfortunately you're pretty much limited to FTP...",
creation_date: "2009-05-04T13:45:37.030",
},
});
console.log(response);
const response1 = await client.index({
index: "child_example",
id: 3,
routing: 1,
refresh: "true",
document: {
join: {
name: "answer",
parent: "1",
},
owner: {
location: "Norfolk, United Kingdom",
display_name: "Troll",
id: 49,
},
body: "Use Linux...",
creation_date: "2009-05-05T13:45:37.030",
},
});
console.log(response1);
PUT child_example/_doc/2?routing=1
{
"join": {
"name": "answer",
"parent": "1"
},
"owner": {
"location": "Norfolk, United Kingdom",
"display_name": "Sam",
"id": 48
},
"body": "<p>Unfortunately you're pretty much limited to FTP...",
"creation_date": "2009-05-04T13:45:37.030"
}
PUT child_example/_doc/3?routing=1&refresh
{
"join": {
"name": "answer",
"parent": "1"
},
"owner": {
"location": "Norfolk, United Kingdom",
"display_name": "Troll",
"id": 49
},
"body": "<p>Use Linux...",
"creation_date": "2009-05-05T13:45:37.030"
}
The following request can be built that connects the two together:
resp = client.search(
index="child_example",
size="0",
aggs={
"top-tags": {
"terms": {
"field": "tags.keyword",
"size": 10
},
"aggs": {
"to-answers": {
"children": {
"type": "answer"
},
"aggs": {
"top-names": {
"terms": {
"field": "owner.display_name.keyword",
"size": 10
}
}
}
}
}
}
},
)
print(resp)
response = client.search(
index: 'child_example',
size: 0,
body: {
aggregations: {
"top-tags": {
terms: {
field: 'tags.keyword',
size: 10
},
aggregations: {
"to-answers": {
children: {
type: 'answer'
},
aggregations: {
"top-names": {
terms: {
field: 'owner.display_name.keyword',
size: 10
}
}
}
}
}
}
}
}
)
puts response
const response = await client.search({
index: "child_example",
size: 0,
aggs: {
"top-tags": {
terms: {
field: "tags.keyword",
size: 10,
},
aggs: {
"to-answers": {
children: {
type: "answer",
},
aggs: {
"top-names": {
terms: {
field: "owner.display_name.keyword",
size: 10,
},
},
},
},
},
},
},
});
console.log(response);
POST child_example/_search?size=0
{
"aggs": {
"top-tags": {
"terms": {
"field": "tags.keyword",
"size": 10
},
"aggs": {
"to-answers": {
"children": {
"type" : "answer"
},
"aggs": {
"top-names": {
"terms": {
"field": "owner.display_name.keyword",
"size": 10
}
}
}
}
}
}
}
}
The above example returns the top question tags and per tag the top answer owners.
Possible response:
{
"took": 25,
"timed_out": false,
"_shards": {
"total": 1,
"successful": 1,
"skipped" : 0,
"failed": 0
},
"hits": {
"total" : {
"value": 3,
"relation": "eq"
},
"max_score": null,
"hits": []
},
"aggregations": {
"top-tags": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "file-transfer",
"doc_count": 1,
"to-answers": {
"doc_count": 2,
"top-names": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "Sam",
"doc_count": 1
},
{
"key": "Troll",
"doc_count": 1
}
]
}
}
},
{
"key": "windows-server-2003",
"doc_count": 1,
"to-answers": {
"doc_count": 2,
"top-names": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "Sam",
"doc_count": 1
},
{
"key": "Troll",
"doc_count": 1
}
]
}
}
},
{
"key": "windows-server-2008",
"doc_count": 1,
"to-answers": {
"doc_count": 2,
"top-names": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "Sam",
"doc_count": 1
},
{
"key": "Troll",
"doc_count": 1
}
]
}
}
}
]
}
}
}