Why You Cannot Just Install the Extension

Managed cloud PostgreSQL services don't let you place files on the server filesystem. The standard PostgreSQL extension mechanism (CREATE EXTENSION) requires a .control file and a SQL file to exist in the server's extension directory — a path you cannot write to on any managed service.

There's a second, independent problem behind the first: because pg_relay itself is typically deployed via direct SQL on managed services (not via CREATE EXTENSION), it doesn't appear in pg_extension. This means CREATE EXTENSION pg_relay_notifier would fail with a missing-dependency error even if you somehow had filesystem access — PostgreSQL checks pg_extension to satisfy the requires = 'pg_relay'-shaped expectation pg_relay_notifier's own install script enforces manually (it isn't a control-file requires, precisely because it has to work in this exact scenario — see the Technical Reference).

pg_relay_notifier is a pure SQL extension — it contains no compiled code. The entire extension can be deployed by running its SQL file directly against the database. The result is functionally identical to CREATE EXTENSION pg_relay_notifier: the same schema, tables, and functions are created, and the same pg_relay registrations happen.

	CREATE EXTENSION	Manual SQL deployment
Installation	CREATE EXTENSION pg_relay_notifier	CREATE SCHEMA pgrelay_notifier + run install/pg_relay_notifier--managed--1.0.sql
Removal	DROP EXTENSION pg_relay_notifier	DROP SCHEMA pgrelay_notifier CASCADE
Upgrade	ALTER EXTENSION pg_relay_notifier UPDATE	Apply the updated managed SQL file manually
Extension catalogue	Appears in pg_extension	Does not appear in pg_extension — verify with SELECT pgrelay_notifier.interface_version(); instead

Everything else — SMTP and Microsoft 365 delivery, profiles, channels, retries, the debug trace, the Oracle UTL_MAIL-style functions — is identical. See Installing on Managed PostgreSQL for the actual steps.

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