数据结构如下：最多4级。有70w+ 数据，现在想查询并进行分类处理。按城市区域划分等级。我的想法是想一次性查出来，进行递归处理。但是现在出现问题。我用mongoose find会超时;请问如何处理这些数据达到我想要的。

{
    "_id" : ObjectId("59df0ea9c43b39bc29e7355e"),
    "id" : 1,
    "parent_id" : 0,
    "level" : 0,
    "area_code" : NumberLong(110000000000),
    "zip_code" : 0,
    "city_code" : "",
    "name" : "北京市",
    "short_name" : "北京",
    "merger_name" : "北京",
    "pinyin" : "BeiJing",
    "lng" : 116.407526,
    "lat" : 39.90403
}
{
    "_id" : ObjectId("59df0ea9c43b39bc29e7355f"),
    "id" : 2,
    "parent_id" : 1,
    "level" : 1,
    "area_code" : NumberLong(110100000000),
    "zip_code" : 100000,
    "city_code" : 10,
    "name" : "直辖区",
    "short_name" : "北京",
    "merger_name" : "北京",
    "pinyin" : "BeiJing",
    "lng" : 116.407526,
    "lat" : 39.90403
}
{
    "_id" : ObjectId("59df0ea9c43b39bc29e73560"),
    "id" : 3,
    "parent_id" : 2,
    "level" : 2,
    "area_code" : NumberLong(110101000000),
    "zip_code" : 100000,
    "city_code" : 10,
    "name" : "东城区",
    "short_name" : "东城",
    "merger_name" : "北京,东城",
    "pinyin" : "DongCheng",
    "lng" : 116.416357,
    "lat" : 39.928353
}
{
    "_id" : ObjectId("59df0ea9c43b39bc29e73561"),
    "id" : 4,
    "parent_id" : 3,
    "level" : 3,
    "area_code" : NumberLong(110101001000),
    "zip_code" : 100006,
    "city_code" : 10,
    "name" : "东华门街道办事处",
    "short_name" : "东华门",
    "merger_name" : "北京,东城,东华门",
    "pinyin" : "DongHuaMen",
    "lng" : 116.406708,
    "lat" : 39.914219
}
{
    "_id" : ObjectId("59df0ea9c43b39bc29e73562"),
    "id" : 5,
    "parent_id" : 4,
    "level" : 4,
    "area_code" : NumberLong(110101001001),
    "zip_code" : 100010,
    "city_code" : 10,
    "name" : "多福巷社区居委会",
    "short_name" : "多福巷",
    "merger_name" : "北京,东城,东华门,多福巷",
    "pinyin" : "DuoFuXiang",
    "lng" : 116.412747,
    "lat" : 39.923014
}