create table referer_sites
(
	site_id integer identity,
	name varchar(255),
	home varchar(255),

	primary key (site_id)
);

create table referer_urls
(
	url_id integer identity,
	url varchar(255),
	link_text varchar(255),
	is_valid integer,

	primary key (url_id)
);

create table referer_service_2
(
	site_id integer,
	url_id integer,
	last_visit_date datetime,
	count integer,

	primary key (site_id, url_id),
	foreign key (site_id) references referer_sites,
	foreign key (url_id) references referer_urls
);

create index idx_rsn on referer_sites(name);