--- /dev/null
+/*
+ * DB migration from v01 to v02 (postgres)
+ */
+BEGIN;
+
+CREATE DOMAIN DM_TARIFF_PERIOD AS TEXT NOT NULL
+ CONSTRAINT valid_value CHECK (VALUE = 'month' OR VALUE = 'day');
+
+ALTER TABLE tb_tariffs ADD period DM_TARIFF_PERIOD DEFAULT 'month';
+
+UPDATE tb_info SET version = 7;
+
+COMMIT;