MongoDB Collections sizes pretty printed 🌟

collSize.js

use mydb;
 
// Container class
function CollStats(name, storageSizeGB, indexSizeGB, totalSizeGB) {
  this.name = name;
  this.storageSizeGB = storageSizeGB.toFixed(0);
  this.indexSizeGB = indexSizeGB.toFixed(0);
  this.totalSizeGB = totalSizeGB.toFixed(0);
}
 
CollStats.prototype.toString = function toStr() {
  var s = this.name + ', storage = ' + this.storageSizeGB + ' GB, index = ' + 
          this.indexSizeGB + ' GB, total = ' + this.totalSizeGB + ' GB';
  return s;
}
 
var bytesInGB = 1024 * 1024 * 1024;
var collectionNames = db.getCollectionNames();
var collStats = [];
for (i = 0; i < collectionNames.length; i++) {
  coll = collectionNames[i];
  s = db[coll].stats();
  var storageSizeGB = s['storageSize'] / bytesInGB;
  var indexSizeGB = s['totalIndexSize'] / bytesInGB;
  var totalSizeGB = storageSizeGB + indexSizeGB;
  var cs = new CollStats(s['ns'], storageSizeGB, indexSizeGB, totalSizeGB);
  collStats.push(cs);
}
 
// descending order sort
collStats.sort(function compare(a, b) {
  return b.totalSizeGB - a.totalSizeGB;
});
 
for (var i = 0; i < collStats.length; i++) {
  print(collStats[i]);
}