--- services/univention-s4-connector/modules/univention/s4connector/lockingdb.py
+++ services/univention-s4-connector/modules/univention/s4connector/lockingdb.py
@@ -152,6 +152,8 @@ class LockingDB:
 		sql_commands = [
 			"CREATE TABLE IF NOT EXISTS S4_LOCK (id INTEGER PRIMARY KEY, guid TEXT);",
 			"CREATE TABLE IF NOT EXISTS UCS_LOCK (id INTEGER PRIMARY KEY, uuid TEXT);",
+			"CREATE INDEX IF NOT EXISTS s4_lock_guid ON s4_lock(guid);",
+			"CREATE INDEX IF NOT EXISTS ucs_lock_uuid ON ucs_lock(uuid);",
 		]
 
 		self.__execute_sql_commands(sql_commands, fetch_result=False)
--- services/univention-s4-connector/modules/univention/s4connector/s4cache.py
+++ services/univention-s4-connector/modules/univention/s4connector/s4cache.py
@@ -186,7 +186,10 @@ class S4Cache:
 		sql_commands = [
 			"CREATE TABLE IF NOT EXISTS GUIDS (id INTEGER PRIMARY KEY, guid TEXT);",
 			"CREATE TABLE IF NOT EXISTS ATTRIBUTES (id INTEGER PRIMARY KEY, attribute TEXT);",
-			"CREATE TABLE IF NOT EXISTS DATA (id INTEGER PRIMARY KEY, guid_id INTEGER, attribute_id INTEGER, value TEXT);"
+			"CREATE TABLE IF NOT EXISTS DATA (id INTEGER PRIMARY KEY, guid_id INTEGER, attribute_id INTEGER, value TEXT);",
+			"CREATE INDEX IF NOT EXISTS data_foreign_keys ON data(guid_id, attribute_id);",
+			"CREATE INDEX IF NOT EXISTS attributes_attribute ON attributes(attribute);",
+			"CREATE INDEX IF NOT EXISTS guids_guid ON guids(guid);",
 		]
 
 		self.__execute_sql_commands(sql_commands, fetch_result=False)