Grants the user, created by the ensureUser attr, superuser permissions. From the postgres docs:
A database superuser bypasses all permission checks, except the right to log in. This is a dangerous privilege and should not be used carelessly; it is best to do most of your work as a role that is not a superuser. To create a new database superuser, use CREATE ROLE name SUPERUSER. You must do this as a role that is already a superuser.
More information on postgres roles can be found here.
Declarations
Type
null or booleanDefault
{
_type = "literalMD";
text = "`null`: do not set. For newly created roles, use PostgreSQL's default. For existing roles, do not touch this clause.\n";
}