PostgreSQL

The other relational database. Chosen instead of MariaDB, never beside it: a stack runs one database, and choosing PostgreSQL is what stands MariaDB aside.

Choose it when your application is written for it — plenty of Laravel, Symfony, Node and Go applications are — or when you need something only it has. Drupal runs on it too. It is chosen when the environment is configured; vallic.yaml cannot switch an environment's database, because moving from one to another means moving everything in it.

#Connecting to it

The same names as every other database:

DB_HOST      the service name
DB_PORT      5432
DB_DRIVER    pgsql
DB_NAME
DB_USER
DB_PASSWORD
DATABASE_URL all of it as one connection string

DB_USER is the application's own user, not the superuser. The database, the user and the password are made for the environment and never change. See Variables for the full list.

#Versions

A deprecated version still runs and is still what some sites are on. It is listed so you can move before it goes, rather than finding out on the morning a build stops resolving it.

Pin the version, not the build: name 18.6 and the platform matches it to the current build, so a security rebuild reaches you without anybody editing a repository.

The version you name is the one your environment runs from the next deploy. This service keeps data, and not every version can read another's — before you change it, read Changing a service's version.

#What you can change

In vallic.yaml — what each one does is on Service settings:

services:
  - postgres:
      version: '18.6'
      environment:
        POSTGRES_MAX_CONNECTIONS: …
        POSTGRES_SHARED_BUFFERS: …
        POSTGRES_WORK_MEM: …

Anything not on this list refuses the deploy, naming the variable — rather than being accepted and quietly ignored.