How do big websites like Facebook handle billion of information in their data base

Question

Big websites like Facebook, Instagram have a good performance and I was wondering how they handle and manage billion of data in their database. Do they use databases like MySQL or develop their own.

Answer 1

Facebook uses Mysql to handles data update of every user interactions.
In order to handle hundred million of user updates per second, Facebook would not update their mysql like what we usually do.

They split the database into countless numbers of shardings, sharding is the database paractitioning that separates very large database into smaller for fast and easy manage their data transactions.

The Facebook shards are running on caches in order they could read/write data extensively. Most of the shards are nonstop running, always staying on memory caches and never really return back to server database.