"MongoDB" to see if the collection is fragmented

Reason

MongoDB will save the fragmented collection in the Config.collection collection, and if you need to see the Shard key, you need to find it based on that collection. Many other official Shard shortcut commands are also in the Config library

Three ways to query the Config library

This way you can view the Shard key information

db.collections.find({$and:                            [                            {‘dropped‘:{$ne:true}},  // 没有被删除的                             {‘name‘:‘/dbname/‘}]  // 根据数据库名进行模糊查询})

View Data distribution

use dbname db.colname.getShardDistribution() #可以查看数据分布

The simplest way

use databaseName;db.collectionName.stats().sharded #简单的返回true或者false

"MongoDB" to see if the collection is fragmented