def METHOD_NAME(postgres_instance_name: Optional[pulumi.Input[str]] = None,
                                 resource_group_name: Optional[pulumi.Input[str]] = None,
                                 opts: Optional[pulumi.InvokeOptions] = None) -> pulumi.Output[GetPostgresInstanceResult]:
    """
    Retrieves a postgres Instance resource
    :param str postgres_instance_name: Name of Postgres Instance
    :param str resource_group_name: The name of the Azure resource group
    """
    ...