// start single node replica set 
// mlaunch init --replicaset --node 1

function makeid(length) {
    let result = '';
    const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    const charactersLength = characters.length;
    let counter = 0;
    while (counter < length) {
      result += characters.charAt(Math.floor(Math.random() * charactersLength));
      counter += 1;
    }
    return result;
}
// generate random string
let r = makeid(5000)

for(i=0;i<20000;i++){db.foo.insertOne({r:r, a:ISODate('2023-07-29T11:17:56.215Z')})}
db.foo.aggregate([{$limit: 20000},{$set: {range: {$range: [0,100]}}},{$unwind: "$range"},{$project: {_id:0, range:0}},{$merge: "foo"}])

// replset [direct: primary] test> db.foo.stats(1024*1024).storageSize
// 10458.5703125

// create ttl index 
db.foo.createIndex({a:1},{expireAfterSeconds: 3600 })


// replset [direct: primary] test> db.foo.stats(1024*1024).indexSizes
// { _id_: 145.9453125, a_1: 77.34765625 }
// replset [direct: primary] test> db.foo.stats(1024*1024).storageSize
// 16110.84375