Partial Update Multi Level Nested Document

[Orijit (Orijit Banerjee)]

Hi

Using Elasticsearch 1.7.1, I have the following document structure

"_source" : {
"questions" : {
	"defaultQuestion" : {			
		"tag" : 0,
		"gid" : 0,
		"rid" : 0,
		"caption" : "SRID",			
	},
	"tableQuestion" : {
		"rows" : [{
				"ids" : {						
					"answerList" : ["3547", "3548"],						
					"tag" : "0",
					"caption" : "Accounts",						
				},
				"name" : {						
					"answerList" : ["Some Name"],						
					"tag" : "0",
					"caption" : "Name",						
				}
			}
		],
		"caption" : "BPI 1500541753537",
		"id" : 644251570,
		"tag" : ""
	}
},
"id" : "447722821"	
}

I want to add a new object in in questions.tableQuestion.rows. My current script is

{ "update": {"_id": "935663867", "_retry_on_conflict" : 3} }
{ "script" : "ctx._source.questions += param1", "params" : {"param1" : {"tableQuestion": {"rows" : [ NEWROWOBJECT ]}  } }}

This is replacing the existing object with the new one. Kindly suggest how to append it.

Thanks
Orijit