Index: database.sql
==================================================================
--- database.sql
+++ database.sql
@@ -134,22 +134,40 @@
 	LANGUAGE sql immutable STRICT
 	AS $$
 select mark(get_site($1), $2) as result;
 $$;
 
--- this function adds tag to domain with regexp
-CREATE or replace FUNCTION mark(domain text, tags text[], regexp text) RETURNS integer
-	LANGUAGE sql immutable STRICT
+-- this function sets tags for site/regexp pair
+CREATE or replace FUNCTION set(my_id_site integer, my_id_tag integer) RETURNS integer
+	LANGUAGE sql STRICT
+	AS $$
+delete from urls where $1 = id_site and regexp is null;
+insert into urls (id_site, id_tag) values ($1, $2);
+select $1;
+$$;
+
+-- this function sets tags for site/regexp pair
+CREATE or replace FUNCTION set(my_id_site integer, my_id_tag integer, my_regexp text) RETURNS integer
+	LANGUAGE sql STRICT
 	AS $$
-select mark(get_site($1), get_tag($2), $3) as result;
+delete from urls where $1 = id_site and $3 = regexp;
+insert into urls (id_site, id_tag, regexp) values ($1, $2, $3);
+select $1;
+$$;
+
+-- this function stores new data for site/regexp pair
+create or replace function set(domain text, tags text, regexp text) returns integer
+	language sql immutable strict
+	as $$
+select set(get_site($1), get_tag($2::text[]), $3);
 $$;
 
--- this function adds tag to domain with regexp
-CREATE or replace FUNCTION mark(domain text, tags text[]) RETURNS integer
-	LANGUAGE sql immutable STRICT
-	AS $$
-select mark(get_site($1), get_tag($2), NULL) as result;
+-- this function stores new data for site/regexp pair
+create or replace function set(domain text, tags text) returns integer
+	language sql immutable strict
+	as $$
+select set(get_site($1), get_tag($2::text[]));
 $$;
 
 -- this function returns id of tag array
 create or replace function get_tag(my_tag text[]) returns integer
 	language plpgsql strict

Index: st-load.py
==================================================================
--- st-load.py
+++ st-load.py
@@ -37,16 +37,17 @@
 				config['host'],
 				config['database'],
 		) )
 
 	def load(self, csv_data):
-		insert = self._db.prepare("select mark($1, array[$2], $3)")
+		insert = self._db.prepare("select set($1, $2, $3)")
 		with self._db.xact():
 			config.section('loader')
 			if config['drop_database']:
-				self._db.execute('delete from urls; delete from site;');
-				#print('dropped', config['drop_database'])
+				self._db.execute('delete from urls;')
+				if config['drop_site']:
+					self._db.execute('delete from site;');
 			for row in csv_data:
 				insert(row[0], row[1], row[2])
 		self._db.execute('vacuum analyze site;')
 		self._db.execute('vacuum analyze urls;')
 
@@ -66,10 +67,11 @@
 			'host': 'localhost',
 			'database': 'squidTag',
 		},
 		'loader': {
 			'drop_database': False,
+			'drop_site': False,
 	},}
 
 	# function to read in config file
 	def __init__(self):
 		parser = optparse.OptionParser()
@@ -77,16 +79,22 @@
 			help = 'config file location', metavar = 'FILE',
 			default = '/usr/local/etc/squid-tagger.conf')
 		parser.add_option('-d', '--drop-database', dest = 'drop_database',
 			help = 'signals loader to drop previous database',
 			action = 'store_true')
+		parser.add_option('-D', '--drop-site', dest = 'drop_site',
+			help = 'signals loader to drop not only url definitions but site index too',
+			action = 'store_true')
 
 		(options, args) = parser.parse_args()
 
 		if options.drop_database:
 			self._default['loader']['drop_database'] = True
 
+		if options.drop_site:
+			self._default['loader']['drop_site'] = True
+
 		if not os.access(options.config, os.R_OK):
 			print("Can't read {}: exitting".format(options.config))
 			sys.exit(2)
 
 		self._config = configparser.ConfigParser()