PostgreSQL 15+: 'ERROR: permission denied for schema public' when a non-owner user creates tables (migrations that worked on PostgreSQL 14 now fail). What changed and how do I grant the right permissions?

Cause: PostgreSQL 15 changed two defaults for new databases. The PUBLIC role (every user) no longer has CREATE permission on the public schema, and the public schema is now owned by the pg_database_owner role, meaning the database's owner. The release notes describe this as adopting the secure schema usage pattern recommended since CVE-2018-1058. So an application user that isn't the database owner can still use existing objects it's been granted, but can't create new tables in public. Upgraded clusters and restored dumps keep their old permissions, which is why it often appears only on fresh PostgreSQL 15+ installs, new managed databases or new Docker containers. Fix (pick one): 1. Make the application role the owner of its database (CREATE DATABASE app OWNER app_user; or ALTER DATABASE app OWNER TO app_user;). As owner it owns the public schema and can create objects. 2. Or grant only what's needed on public to that role: GRANT USAGE, CREATE ON SCHEMA public TO app_user; (run as the database owner or a superuser, in that database). 3. Better for multi-user databases: give each application its own schema: CREATE SCHEMA app AUTHORIZATION app_user; and set search_path for that role (ALTER ROLE app_user SET search_path = app;). 4. Restoring the old behavior for everyone (GRANT CREATE ON SCHEMA public TO PUBLIC;) works, but the release notes suggest it only for databases with no need to defend against other users. 5. In migrations tools and ORMs, make sure the migration runs as the role that owns or has CREATE on the target schema, and that later app connections have USAGE plus the table privileges they need (consider ALTER DEFAULT PRIVILEGES for new tables). Verify: as the app user, \dn+ public in psql shows the expected privileges, and the migration's CREATE TABLE succeeds. Sources: https://www.postgresql.org/docs/release/15.0/ https://www.postgresql.org/docs/current/ddl-schemas.html