Field with different types on same index

Elastic Stack Elasticsearch
5

Just in case you are interest here is a sample ingest pipeline / simulate with various combinations

## Ingest Pipeline Concrete / Object
POST _ingest/pipeline/_simulate
{
  "pipeline": {
    "processors": [
      {
        "rename": {
          "if": "ctx?.notes instanceof String", 
          "field": "notes",
          "target_field": "notes.value",
          "ignore_failure": false
        }
      }
    ]
  },
  "docs": [
    {
      "_source": {
        "id": "8f22efb2-6a2a-4cb7-9d0b-01ca0d6cff2e",
        "notes": {
          "created_at": "2022/01/01",
          "value": "This is some random note"
        },
        "first_name": "Some name",
        "integration": "CRM_A"
      }
    },
    {
      "_source": {
        "id": 1,
        "notes": "This is a random note text",
        "name": "Some random name",
        "integration": "CRM_A"
      }
    },
    {
      "_source": {
        "id": 1,
        "name": "Some random name",
        "integration": "CRM_A"
      }
    }
  ]
}

Results

{
  "docs": [
    {
      "doc": {
        "_index": "_index",
        "_id": "_id",
        "_version": "-3",
        "_source": {
          "integration": "CRM_A",
          "notes": {
            "created_at": "2022/01/01",
            "value": "This is some random note"
          },
          "id": "8f22efb2-6a2a-4cb7-9d0b-01ca0d6cff2e",
          "first_name": "Some name"
        },
        "_ingest": {
          "timestamp": "2022-09-23T23:23:13.461958276Z"
        }
      }
    },
    {
      "doc": {
        "_index": "_index",
        "_id": "_id",
        "_version": "-3",
        "_source": {
          "name": "Some random name",
          "integration": "CRM_A",
          "id": 1,
          "notes": {
            "value": "This is a random note text"
          }
        },
        "_ingest": {
          "timestamp": "2022-09-23T23:23:13.461985402Z"
        }
      }
    },
    {
      "doc": {
        "_index": "_index",
        "_id": "_id",
        "_version": "-3",
        "_source": {
          "name": "Some random name",
          "integration": "CRM_A",
          "id": 1
        },
        "_ingest": {
          "timestamp": "2022-09-23T23:23:13.461991898Z"
        }
      }
    }
  ]
}