Elastic search mapping issue with tire - ruby-on-rails

Question

Following is the mapping in Occurrence model
mapping do
indexes :_event_id, type: 'integer', index: :not_analyzed,boost: 1000
indexes :start, type: 'date', index: :not_analyzed , boost: 100
indexes :events do
indexes :price, type: 'integer',boost: 100
indexes :title, boost: 700
indexes :description, boost: 200
indexes :acts do
indexes :name ,boost: 800
end
indexes :venue do
indexes :name ,boost: 500
end
indexes :tags do
indexes :name, boost: 1000
end
end
end
when I try to run rake environment tire:import CLASS=Occurrence FORCE=true
initially it generated mapping as below
{
"occurrences": {
"occurrence": {
"properties": {
"_event_id": {
"type": "integer",
"boost": 1000.0,
"omit_norms": false
},
"events": {
"properties": {
"acts": {
"properties": {
"name": {
"type": "string",
"boost": 800.0
}
}
},
"description": {
"type": "string",
"boost": 200.0
},
"price": {
"type": "integer",
"boost": 100.0,
"omit_norms": false
},
"tags": {
"properties": {
"name": {
"type": "string",
"boost": 1000.0
}
}
},
"title": {
"type": "string",
"boost": 700.0
},
"venue": {
"properties": {
"name": {
"type": "string",
"boost": 500.0
}
}
}
}
},
"start": {
"type": "date",
"boost": 100.0,
"omit_norms": false,
"format": "dateOptionalTime"
}
}
}
}
}
But after process started ,the above mapping is changed as below
{
"occurrences": {
"occurrence": {
"properties": {
"_event_id": {
"type": "integer",
"boost": 1000.0,
"omit_norms": false
},
"acts": {
"properties": {
"name": {
"type": "string"
}
}
},
"created_at": {
"type": "date",
"format": "dateOptionalTime"
},
"day_of_week": {
"type": "long"
},
"deleted": {
"type": "boolean"
},
"end": {
"type": "date",
"format": "dateOptionalTime"
},
"event_id": {
"type": "long"
},
"events": {
"properties": {
"acts": {
"properties": {
"name": {
"type": "string",
"boost": 800.0
}
}
},
"description": {
"type": "string",
"boost": 200.0
},
"price": {
"type": "integer",
"boost": 100.0,
"omit_norms": false
},
"tags": {
"properties": {
"name": {
"type": "string",
"boost": 1000.0
}
}
},
"title": {
"type": "string",
"boost": 700.0
},
"venue": {
"properties": {
"name": {
"type": "string",
"boost": 500.0
}
}
}
}
},
"id": {
"type": "long"
},
"recurrence_id": {
"type": "long"
},
"slug": {
"type": "string"
},
"start": {
"type": "date",
"boost": 100.0,
"omit_norms": false,
"format": "dateOptionalTime"
},
"tags": {
"properties": {
"name": {
"type": "string"
}
}
},
"updated_at": {
"type": "date",
"format": "dateOptionalTime"
},
"venue": {
"properties": {
"description": {
"type": "string"
},
"name": {
"type": "string"
}
}
}
}
}
}
}
Venue is coming two times with additional fields.
Can anyone please help me, why the mapping is getting change?
Thanks