[lmm]

If you're using that kind of schema you won't be getting any of Postgres' advantages. Obviously it has a pretty good reliability reputation, but I'd be very cautious about switching to Postgres because you're going to be making a lot of work for yourself.

If you're worried about performance, benchmark it (or find someone who has). On the reliability side there are plenty of NoSQL options with better reputations than MongoDB. My first thought is neo4j, but I don't really know enough about your particular problem.

[brittonrt]

Thanks for the reply. From what I understand, the schema I described is similar to what Reddit uses in their Postgres setup. You mentioned that I "won't be getting any of Postgres' advantages", what are some of the most important considerations that play into Postgres strengths? What are the primary advantages you for Postgres your referring to?

Thanks!

[lmm]

I meant just in terms of Postgres expecting a "standard" relational schema; the interface and query planner and the like are designed around that. It's not a bad schemaless data store per se, but it's not really designed for that use case, so I would expect rough edges when using it that way.

The modern selection of schemaless data stores weren't as mature (if they even existed) when Reddit was getting started, so don't assume that they would choose that architecture if they were starting today. I suspect that if you build on postgres in this way you'll have to write significant pieces of functionality by hand that you get for free with mongodb/couchdb/redis/neo4j/etc.

That said I'll emphasise again that I don't know too much about your system; at some point, prototyping and measuring will be the only way to see what works best for you.

[brittonrt]

Just checked out neo4j, it looks pretty great, I'm surprised I hadn't heard of it before. Thanks for the heads up!