Questions about supported PostgreSQL versions for RDS

[travishaagen]

Why is floci using Postgres 16 by default, and should we expect Postgres 18 to work, given that RDS supports that version?

Question raised when hitting this issue #1959

[Krishnakr21]

Floci uses PostgreSQL 16 by default because the RDS service currently defaults to the postgres:16-alpine image. This seems to be a conservative/default compatibility choice rather than a limitation of RDS itself.

Since AWS RDS officially supports PostgreSQL 18, I’d expect PostgreSQL 18 to work with Floci as well, especially since the PostgreSQL image is configurable. However, it would still be worth testing the RDS lifecycle and connection flow with postgres:18-alpine before considering it officially supported.

So I think PG18 support should be feasible, but it would be good to verify it against Floci’s RDS implementation and test suite first.