def get_resource_type(policy):
    """
    Return resource type of the policy.
    :param policy: Policy structure.
    :return: Resource type used in policy (database, tag, path).
    """
    if policy["policyType"] != 0:
        raise AttributeError(
            "PolicyType must be 0 to support option expandHiveResourceToHdfs. Policy: {}".format(policy["name"]))
    resources = policy["resources"]
    if "database" in resources:
        return "database"
    if "tag" in resources:
        return "tag"
    if "path" in resources:
        return "path"
    return "unknown"