How can I get size (bytes) of a MongoDB collection with Mongoose?

Question

Imagine I have a Mongoose model like this:

mongoose = require('mongoose')
Products = mongoose.model('Products')

How do I get size of the full corresponding collection in bytes? I found db.collection.storageSize, but it's nowhere to be found in the Mongoose API docs.

Timotheus

Answer 1

Mongoose doesn't provide an abstraction for this, but you can access the native driver collection methods like stats() from the collection property of a Mongoose Model. That method provides the collection's size as the storageSize property of the results:

Products.collection.stats(function(err, results) {
    console.log(results.storageSize);
});

Intelligence

what if I wanted to check the size of whole database, the situation is I have 500mb of free MongoDB hosting and I wanted to display on admin panel how much database is remaining and also genrate emails when reaching 90% to avoid any inconvenience because of database full, the answer could be "get all sizes of all collections one by one and then add" I understand but it would be more convenient if there is a way to get size of whole database at once, any help would be appriciated – Caseinogen

Best to post that as a new question @InzamamMalik – Intelligence

const stats = await mongoose.connection.db.stats() – Demission

Answer 2

var stats = Products.stats(function(err, stats) {
  // second parameter stats contains the result from  stats
  var storageSize = stats.storageSize;
});

gets statistics for Products collection.

Mansfield

Where did you get the db object using Mongoose? – Timotheus

Sorry, using Mongoose model you should be able to just use it... See my updated answer – Mansfield

Answer 3

When I tried to use .stats() to get the storage size, the lib shows that the method stats() has been deprecated. The pipeline $collstats in aggregation is the correct way to acquire the data size in bytes.

https://www.mongodb.com/docs/manual/reference/operator/aggregation/collStats/

db.collection.aggrate([{
 {
  $collStats:
    {
      // Kb=>scale=1024,...
      storageStats: { scale: <number> }, 
    }
 }
}])

The output will contain the storageStats like this

Vicariate