Unwind in ElasticSearch

Question

I am currently having the below index in ElasticSearch

PUT my_index
{
  "mappings": {
    "doc": {
      "properties": {
        "type" : {
          "type": "text",
          "fielddata": true
        },
        "id" : {
          "type": "text",
          "fielddata": true
        },
        "nestedTypes": {
          "type": "nested",
          "properties": {
            "nestedTypeId":{
              "type": "integer"
            },
            "nestedType":{
              "type": "text",
              "fielddata": true
            },
            "isLead":{
              "type": "boolean"
            },
            "share":{
              "type": "float"
            },
            "amount":{
              "type": "float"
            }
          }
        }
      }
    }
  }
}

I need the nested types to be displayed in a HTML table along with the id and type fields in each row.

I am trying to achieve something similar to unwind in MongoDB.

I have tried the reverse nested aggregation as below

GET my_index/_search
{
  "size": 0,
  "aggs": {
"NestedTypes": {
  "nested": {
    "path": "nestedTypes"
  },
  "aggs": {
    "NestedType": {
      "terms": {
        "field": "nestedTypes.nestedType",
        "order": {
          "_key": "desc"
        }
      },
      "aggs": {
        "Details": {
          "reverse_nested": {}, 
          "aggs": {
            "type": {
              "terms": {
                "field": "type"
              }
            },
            "id": {
              "terms": {
                "field": "id"
              }
            }
          }
        }
      }
    }
  }
}
  }
}

But the above returns only one field from the nestedTypes, but I need all of them.

Also, I need sorting and pagination for this table. Could you please let me know how this can be achieved in ElasticSearch.

Answer 1

ElasticSearch does not support this operation out of the box. When a request was raised to implement the same in git, the below response was given:

We discussed it in Fixit Friday and agreed that we won't try to implement it due to the fact that we can't think of a way to support such operations efficiently.

The only ideas that we thought were reasonable boiled down to having another index that stores the same data but flattened. Depending on your use-case, you might be able to maintain those two views in parallel or would only maintain the one you have today, then materialize a flattened view of the data when you need it and throw it away after you are done querying. In both cases, this requires client-side logic.

The link to the request is here