删除错误数据
```
db.eosset.find({"block_num" : {$exists:false}})
db.eosset.remove({"block_num" : {$exists:false}})
```

创建索引
```
db.eosset.ensureIndex({"block_num": 1},{unique: true})

db.eosset.ensureIndex({"transactions.trx.transaction.actions.account": 1})

db.eosset.ensureIndex({"transactions.trx.transaction.actions.name": 1})
```

查看最后一条记录
```
db.eosset.find().sort({"block_num":,-1}).limit(1)
```