Bifalgorithm post

"You should never confuse database replication with database backups. When we run a database for our users, it is generally a best practice to have two replicas for this database. Basically, we have three database copies sitting on three separate machines. These two replicas are connected to the primary database with a persistent connection, and whenever a change is made to the primary database, the same change gets copied to the replicas, so that the replicas are up to date and in sync with the primary database. This is basically the database replication strategy. Now, if the primary database crashes or fails, a replica gets promoted to primary database within a few seconds, and users never notice that our database failed. So when someone asks if you're also taking backups of your data, you might think, I already have three copies of everything. Why do I need backup? Well, this is one of those setups that can hurt you if you don't take backups. Because a replica never checks what it's copying from the primary database, whatever happens in the primary also happens in the replicas. Now, say a developer or your AI agent runs a delete query. and they end up deleting 10 million rows. The replicas will see this delete in the primary database, and because the replicas follow the primary faithfully, replicas also delete 10 million rows from themselves within milliseconds. All three copies are now in sync, and they all deleted those 10 million rows. Replication was never protecting your data. Replication was protecting your uptime. Therefore, backups are very, very important for your system. You take a snapshot of your database, and then you ship it somewhere completely disconnected so that if something happens to your system, you can fall back to this backup."

"You should never confuse database replication with database backups. When we run a database for our users, it is generally a best practice to have two replica…