3 ms·

How is (a) wrong? Pg doesn't horizontally scale like Mongo does

re-thc 3y ago
> Pg doesn't horizontally scale like Mongo does At what cost though? Does 1 Pg server = 1 Mongo server for the same specs or do you need a lot more Mongo servers?
coldtea 3y ago
Between plain old horizontal scaling via custom sharding, replicas, and extensions like Citus and Timescale that offer full horizontal scalability, Postgres is handling some of the biggest use cases in the world.
- endisneigh 3y ago
  It's simply a fact that Postgres does not offer out of the box scaling like MongoDB. Postgres does have things like Citus, or even wire-protocol compatible things like CockroachDB that do scale, but those are not Postgres. It's the same situation with MySQL vs. Vitess.
  - riku_iki 3y ago
    > but those are not Postgres. sure, citus is an extension of postgres and part of ecosystem.
    - hot_gril 3y ago
      And it comes with a bunch of caveats. It's bolted-on horizontal scaling, vs MongoDB where that's the main feature. Yes I still prefer Postgres in general, but it's fair to point out that weakness of it.
- threeseed 3y ago
  Citus was acquired by Microsoft so there are doubts about its future longevity given that so many similar promises of ongoing support are rarely maintained. Timescale is optimised for time-series so not sure it's applicable. Point still remains that PostgreSQL lacks a modern, built-in horizontal scalability solution.
  - coldtea 3y ago
    >given that so many similar promises of ongoing support are rarely maintained Microsoft on the other hand is among the best in keeping such promises. If Google had bought it, sure...
    - hot_gril 3y ago
      Well let's see how long Google's Spanner lasts. It's designed to support huge-scale systems, and personally I'd be terrified locking a huge system into that.
  - maxthegeek1 3y ago
    Cockroachdb is a common solution here.
    - aeyes 3y ago
      It's not Postgres, it only speaks Postgres dialect.
    - riku_iki 3y ago
      but it is not pgsql, and doesn't have drop in compatibility..
romanovcode 3y ago
Okey, maybe I do not understand something but how is https://neon.tech https://neon.tech not auto-scaling? Or the more expensive option at AWS Aurora?
- endisneigh 3y ago
  This is not Postgres. It's a managed instance, but isn't built in.
- re-thc 3y ago
  > not auto-scaling? The writes aren't. There's no sharding for example. You can ever only have 1 primary writer.
  - maxbond 3y ago
    Fair, but this is getting fixed. Postgres 16 (which was just released) adds an origin tag to logical replication, so that you can know whether or not to pass on a change (and avoid having an infinite loop where a change is replicated back and forth). That's the first step to having multiple mains. I think in theory, if you had deep Postgres knowledge, you could set up a high touch, bespoke multi-main deployment today. I expect the replication story with Postgres will get much better over the next few years.

> Pg doesn't horizontally scale like Mongo does At what cost though? Does 1 Pg server = 1 Mongo server for the same specs or do you need a lot more Mongo servers?

coldtea 3y ago

Between plain old horizontal scaling via custom sharding, replicas, and extensions like Citus and Timescale that offer full horizontal scalability, Postgres is handling some of the biggest use cases in the world.

endisneigh 3y ago
It's simply a fact that Postgres does not offer out of the box scaling like MongoDB. Postgres does have things like Citus, or even wire-protocol compatible things like CockroachDB that do scale, but those are not Postgres. It's the same situation with MySQL vs. Vitess.
- riku_iki 3y ago
  > but those are not Postgres. sure, citus is an extension of postgres and part of ecosystem.
  - hot_gril 3y ago
    And it comes with a bunch of caveats. It's bolted-on horizontal scaling, vs MongoDB where that's the main feature. Yes I still prefer Postgres in general, but it's fair to point out that weakness of it.
threeseed 3y ago
Citus was acquired by Microsoft so there are doubts about its future longevity given that so many similar promises of ongoing support are rarely maintained. Timescale is optimised for time-series so not sure it's applicable. Point still remains that PostgreSQL lacks a modern, built-in horizontal scalability solution.
- coldtea 3y ago
  >given that so many similar promises of ongoing support are rarely maintained Microsoft on the other hand is among the best in keeping such promises. If Google had bought it, sure...
  - hot_gril 3y ago
    Well let's see how long Google's Spanner lasts. It's designed to support huge-scale systems, and personally I'd be terrified locking a huge system into that.
- maxthegeek1 3y ago
  Cockroachdb is a common solution here.
  - aeyes 3y ago
    It's not Postgres, it only speaks Postgres dialect.
  - riku_iki 3y ago
    but it is not pgsql, and doesn't have drop in compatibility..

romanovcode 3y ago

Okey, maybe I do not understand something but how is https://neon.tech https://neon.tech not auto-scaling? Or the more expensive option at AWS Aurora?

endisneigh 3y ago
This is not Postgres. It's a managed instance, but isn't built in.
re-thc 3y ago
> not auto-scaling? The writes aren't. There's no sharding for example. You can ever only have 1 primary writer.
- maxbond 3y ago
  Fair, but this is getting fixed. Postgres 16 (which was just released) adds an origin tag to logical replication, so that you can know whether or not to pass on a change (and avoid having an infinite loop where a change is replicated back and forth). That's the first step to having multiple mains. I think in theory, if you had deep Postgres knowledge, you could set up a high touch, bespoke multi-main deployment today. I expect the replication story with Postgres will get much better over the next few years.