Postgres¶

uv add "djox[postgres]"  # or: pip install "djox[postgres]"

The postgres extra installs psycopg 3 for Django's sync code. psycopg2 isn't supported: djox raises ImproperlyConfigured without psycopg 3.

# settings.py
DATABASES = {
    "default": {
        "ENGINE": "djox.backends.postgresql",  # was "django.db.backends.postgresql"
        "NAME": "app",
        "USER": "django",
        "PASSWORD": "...",
        "HOST": "localhost",
        "PORT": 5432,
        "OPTIONS": {"async_pool_size": 10},
    }
}

Sync code is Django's own Postgres backend, on psycopg: migrations, the admin, the sync ORM, manage.py test.
Async code runs on a pool of connections that Rust owns: djox's QuerySets, djox.atomic(), djox.connections[alias]. So await Book.objects.aget(...) never takes a thread.
The two are just two clients of the server, so, unlike with SQLite, they can't lose each other's writes.
Everything else works the same: the fast lane, streaming, hooks, djox.atomic(), queries inside TestCase. Writers don't take turns: Postgres locks rows, so many transactions write at once.

Options¶

OPTIONS are psycopg's, as with Django's backend, plus one of djox's:

Option	Default	What it does
`async_pool_size`	`10`	The most connections `djox.connections[alias]` opens at once

The async pool:

connects with the same NAME, USER, PASSWORD, HOST, PORT and libpq settings (connect_timeout, application_name, options, target_session_attrs...);
uses the same time zone as Django's connections;
returns the same Python objects psycopg gives Django (Decimal, aware datetime, UUID, JSON as text...).

TLS¶

Set libpq's TLS options; Django's connections and djox's use the same ones:

"OPTIONS": {
    "sslmode": "verify-full",
    "sslrootcert": BASE_DIR / "rds-ca.pem",  # or "system", the default
},

`sslmode`	Encrypted?	Certificate checked?
`disable`	no
`allow`	if the server offers it	no (djox tries TLS first, libpq last)
`prefer`	if the server offers it	no (the default)
`require`	yes	no, unless `sslrootcert` is given: then like `verify-ca`
`verify-ca`	yes	signed by a trusted authority
`verify-full`	yes	signed by a trusted authority, for this host name

Use verify-full across networks you don't control. Without a check, someone on the network could pretend to be the server.
sslrootcert is a PEM file of the authorities to trust, like your provider's bundle, or "system" for the ones your operating system trusts. djox uses the system's when it isn't given (libpq looks for ~/.postgresql/root.crt instead, so give it explicitly to be sure both agree).
sslcert and sslkey are a client certificate and its key (PEM files), for servers that ask for one.
The encryption is rustls, in Rust: nothing to install.

Not supported yet¶

These raise ImproperlyConfigured instead of being quietly ignored:

service (pg_service.conf) and assume_role.
sslpassword (an encrypted key), sslcrl and sslcrldir.

djox reads DATABASES, not libpq's environment variables (PGSSLMODE, PGHOST...): put the settings in DATABASES.

And from async code:

Array, range and hstore columns raise ProgrammingError ("djox can't read the Postgres type ... yet"). Sync queries are unaffected.