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If I were to start building Reddit from scratch without knowing if it's going to be successful or not, I'd rather iterate quick on features rather trying to spe

If I were to start building Reddit from scratch without knowing if it's going to be successful or not, I'd rather iterate quick on features rather trying to spend time scaling something that will most likely fail before reaching that kind of scale. >True HA is very difficult. Even just automatic failover takes a lot of manual sysadmin effort Nearly all Postgres cloud providers such as RDS, CloudSQL, Upcloud, provide multi-region nodes and automatic failover. Also, true HA databases are very expensive and have their own drawbacks. Not really designed for a Reddit-style startup. >You can't autoscale, and while scaling is a nice problem to have, having to not just fundamentally rearchitect all your code when you need to shard, but also probably migrate all your data, is probably the worst version of it. Hence why I said "as far as I can". I can keep upgrading the instance, creating material views, caching responses, etc. Lastly, the most important reason is because I know Postgres and I can get started today. I don't want to learn a highly scalable, new type of database that I might need 5 years down the road.

lmm 4y ago
> Nearly all Postgres cloud providers such as RDS, CloudSQL, Upcloud, provide multi-region nodes and automatic failover. From memory you have to specify a maintenance window and failover is not instant. And relying on your cloud provider comes with its own drawbacks. > Also, true HA databases are very expensive and have their own drawbacks. Not really designed for a Reddit-style startup. Plenty of free HA datastores out there, and if we're assuming it'll be managed by the cloud provider anyway then that's a wash. > Lastly, the most important reason is because I know Postgres and I can get started today. I don't want to learn a highly scalable, new type of database that I might need 5 years down the road. That's a good argument for using what you know; by the same token I'd use Cassandra. Postgres is a very complex system with lots of legacy and various edge cases.

lmm 4y ago

> Nearly all Postgres cloud providers such as RDS, CloudSQL, Upcloud, provide multi-region nodes and automatic failover. From memory you have to specify a maintenance window and failover is not instant. And relying on your cloud provider comes with its own drawbacks. > Also, true HA databases are very expensive and have their own drawbacks. Not really designed for a Reddit-style startup. Plenty of free HA datastores out there, and if we're assuming it'll be managed by the cloud provider anyway then that's a wash. > Lastly, the most important reason is because I know Postgres and I can get started today. I don't want to learn a highly scalable, new type of database that I might need 5 years down the road. That's a good argument for using what you know; by the same token I'd use Cassandra. Postgres is a very complex system with lots of legacy and various edge cases.