Elasticsearch partial update script: Clear array and replace with new values

Question

I have documents like:

{
  MyProp: [\"lorem\", \"ipsum\", \"dolor\"]
  ... lots of stuff here ...
}

My documents can be quite big (but thes

Answer 1

You can use the update by query API in order to do batch updates. This works since ES 2.3 onwards, otherwise you need to install a plugin.

POST index/_update_by_query
{
  "script": {
    "inline": "ctx._source.myProp += newProp",
    "params": {
      "newProp": "sit"
    }
  },
  "query": {
    "match_all": {}
  }
}

You can of course use whatever query you want in order to select the documents on which MyProp needs to be updated. For instance, you could have a query to select documents having some specific MyProp values to be replaced.

The above will only add a new value to the existing array. If you need to completely replace the MyProp array, then you can also change the script to this:

POST index/_update_by_query
{
  "script": {
    "inline": "ctx._source.myProp = newProps",
    "params": {
      "newProps": ["dolor", "sit"]
    }
  },
  "query": {
    "match_all": {}
  }
}

Note that you also need to enable dynamic scripting in order for this to work.

UPDATE

If you simply want to update a single document you can use the partial document update API, like this:

POST test/type1/1/_update
{
    "doc" : {
        "MyProp" : ["dolor", "sit"]
    }
}

This will effectively replace the MyProp array in the specified document.

If you want to go the bulk route, you don't need scripting to achieve what you want:

POST index/type/_bulk
{ "update" : {"_id" : "1"} }
{ "doc" : {"MyProp" : ["dolor", "sit"] } }
{ "update" : {"_id" : "2"} }
{ "doc" : {"MyProp" : ["dolor", "sit"] } }