{
"_id": ObjectId("5f9d8a005752840001a20804"),
"data": {
"orderNo": "123456789",
}
}
db.zhai.createIndex({"data.orderNo":1})
db.zhai.createIndex({"data.orderNo":1}, {background: true})
db.zhai.find({"data.orderNo":"123456789"}).explain("executionStats")
db.zhai.dropIndex("data.orderNo_1")
db.zhai.dropIndexes()