Elasticsearch - nested types vs collapse/aggs - elasticsearch

Question

I have a use case where I need to find the latest data based on some fields.
The fields are:
category.name
category.type
createdAt
For example: search for the newest data where category.name = 'John G.' AND category.type = 'A'. I expect the data with ID = 1 where it matches the criteria and is the newest one based on createdAt field ("createdAt": "2022-04-18 19:09:27.527+0200")
The problem is that category.* is a nested field and I can't aggs/collapse these fields because ES doesn't support it.
Mapping:
PUT data
{
"mappings": {
"properties": {
"createdAt": {
"type": "date",
"format": "yyyy-MM-dd HH:mm:ss.SSSZ"
},
"category": {
"type": "nested",
"properties": {
"name": {
"type": "text",
"analyzer": "keyword"
}
}
},
"approved": {
"type": "text",
"analyzer": "keyword"
}
}
}
}
Data:
POST data/_create/1
{
"category": [
{
"name": "John G.",
"level": "A"
},
{
"name": "Chris T.",
"level": "A"
}
],
"createdBy": "John",
"createdAt": "2022-04-18 19:09:27.527+0200",
"approved": "no"
}
POST data/_create/2
{
"category": [
{
"name": "John G.",
"level": "A"
},
{
"name": "Chris T.",
"level": "A"
}
],
"createdBy": "Max",
"createdAt": "2022-04-10 10:09:27.527+0200",
"approved": "no"
}
POST data/_create/3
{
"category": [
{
"name": "Rick J.",
"level": "B"
}
],
"createdBy": "Rick",
"createdAt": "2022-03-02 02:09:27.527+0200",
"approved": "no"
}
I'm looking for either a search query that can handle that in an acceptable performant way, or a new object design without nested type where I could take advantage of aggs/collapse feature.
Any suggestion will be really appreciated.

Answer 1

About your first question,
For example: search for the newest data where category.name = 'John G.' AND category.type = 'A'. I expect the data with ID = 1 where it matches the criteria and is the newest one based on createdAt field ("createdAt": "2022-04-18 19:09:27.527+0200")
I believe you can do something along those lines:
GET /72088168/_search
{
"query": {
"nested": {
"path": "category",
"query": {
"bool": {
"must": [
{
"match": {
"category.name": "John G."
}
},
{
"match": {
"category.level": "A"
}
}
]
}
}
}
},
"sort": [
{
"createdAt": {
"order": "desc"
}
}
],
"size":1
}
For the 2nd matter, it really depends on what you are aiming to do. could merge category.name and category.level in the same field. Such that you document would look like:
{
"category": ["John G. A","Chris T. A"],
"createdBy": "Max",
"createdAt": "2022-04-10 10:09:27.527+0200",
"approved": "no"
}
No more nested needed. Although I agree it feels like using tape to fix your issue.