Max Field in MongoDB Collection Stats Output

Use max field in order to limit the number of documents in the collection. Following is the query to use the max field in the capped collection −

> db.createCollection("demo673", { capped : true, size : 100, max :50 } )
{ "ok" : 1 }

Let us create a collection with documents −

> db.demo673.insertOne({Name:"John",Age:23});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5ea3ec7304263e90dac943e8")
}
> db.demo673.insertOne({Name:"Bob",Age:21});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5ea3ec7804263e90dac943e9")
}
> db.demo673.insertOne({Name:"David",Age:20});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5ea3ec7f04263e90dac943ea")
}

Display all documents from a collection with the help of find() method −

> db.demo673.find();

This will produce the following output −

{ "_id" : ObjectId("5ea3ec7304263e90dac943e8"), "Name" : "John", "Age" : 23 }
{ "_id" : ObjectId("5ea3ec7804263e90dac943e9"), "Name" : "Bob", "Age" : 21 }
{ "_id" : ObjectId("5ea3ec7f04263e90dac943ea"), "Name" : "David", "Age" : 20 }