diff --git a/_lib.sql b/_lib.sql
index 3498d7e..db47e23 100644
--- a/_lib.sql
+++ b/_lib.sql
@@ -40,7 +40,10 @@ SELECT x, soa_upd(x) FROM unnest(ARRAY[
 ]) x;
 */
 
-CREATE OR REPLACE FUNCTION domain_id(a_name TEXT, a_type TEXT DEFAULT 'NATIVE') RETURNS INTEGER AS $_$
+-- result was changed to bigint
+DROP FUNCTION IF EXISTS domain_id(text,text);
+
+CREATE OR REPLACE FUNCTION domain_id(a_name TEXT, a_type TEXT DEFAULT 'NATIVE') RETURNS BIGINT AS $_$
 /*
   Вернуть ID домена, создав его при необходимости
 */
@@ -58,7 +61,7 @@ BEGIN
 END
 $_$ LANGUAGE plpgsql;
 
-CREATE OR REPLACE PROCEDURE acme_insert(a_domain_id INT, a_name TEXT, a_ip TEXT, a_ttl INT) AS $_$
+CREATE OR REPLACE PROCEDURE acme_insert(a_domain_id BIGINT, a_name TEXT, a_ip TEXT, a_ttl INT) AS $_$
 /*
   Добавление в зону для заданного a_ip записей для передачи ему контроля над зоной a_name.
   Это используется в DNS-01 challenge ACME
@@ -76,3 +79,70 @@ BEGIN
   ;
 END;
 $_$ LANGUAGE plpgsql;
+
+CREATE OR REPLACE FUNCTION soa_mk(
+  a_domain_id BIGINT
+, a_ns_admin TEXT
+, a_refresh  INTEGER DEFAULT  10800 -- 3 hours
+, a_retry    INTEGER DEFAULT   3600 -- 1 hour
+, a_expire   INTEGER DEFAULT 604800 -- 7 days
+, a_ttl      INTEGER DEFAULT   1800 -- 30 min
+) RETURNS TEXT AS $_$
+/*
+  Получить новый серийный номер зоны, проверить наличие NSERVER и вернуть строку SOA
+
+  refresh -- time lag until the slave again asks the master for a current version of the zone file
+  retry   -- Should this request go unanswered, the “Retry” field regulates when a new attempt is to be carried out (< refresh)
+  expire  -- determines how long the zone file may still be used before the server refuses DNS information delivery
+  ttl     -- how long a client may hold the requested information in the cache before a new request must be sent
+
+  Each value in seconds
+*/
+DECLARE
+  v_ns        text := current_setting('vars.ns');   -- master DNS host
+  v_stamp     text;                       -- zone SOA timestamp
+  v_stamp_old text;                       -- previous zone SOA timestamp
+BEGIN
+  -- check NSERVER
+  IF coalesce(v_ns,'') = '' THEN
+    RAISE EXCEPTION 'NSERVER is not set';
+  END IF;
+  -- calculate SOA with next serial
+  SELECT INTO v_stamp_old split_part(content, ' ', 3) FROM records WHERE domain_id = a_domain_id AND type = 'SOA';
+  v_stamp := soa_upd(v_stamp_old);
+
+  RETURN concat_ws(' ', v_ns, a_ns_admin, v_stamp, a_refresh, a_retry, a_expire, a_ttl);
+END;
+$_$ LANGUAGE plpgsql;
+
+
+CREATE OR REPLACE FUNCTION csum_exists(a_domain_id BIGINT) RETURNS BOOL AS $_$
+/*
+  Проверить совпадение vars.csum с загруженным в БД прошлый раз.
+  Если нет таблицы dcape_csum - создать ее
+  Если csum отличается - обновить
+*/
+DECLARE
+  v_csum     text := current_setting('vars.csum');   -- file csum
+  v_csum_old text;
+BEGIN
+  RAISE NOTICE 'Source csum: %', v_csum;
+  IF to_regclass('public.dcape_csum') IS NULL THEN
+    CREATE TABLE dcape_csum(
+      domain_id bigint primary key REFERENCES domains(id) ON DELETE CASCADE
+    , csum text
+    , updated_at timestamptz(0)
+    );
+  ELSE
+    SELECT INTO v_csum_old csum FROM dcape_csum WHERE domain_id = a_domain_id;
+  END IF;
+  IF v_csum_old IS NULL THEN
+    INSERT INTO dcape_csum(domain_id, csum, updated_at) VALUES (a_domain_id, v_csum, now());
+  ELSIF v_csum_old <> v_csum THEN
+    UPDATE dcape_csum SET csum = v_csum, updated_at = now() WHERE domain_id = a_domain_id;
+  ELSE
+    RETURN TRUE;
+  END IF;
+  RETURN FALSE;
+END;
+$_$ LANGUAGE plpgsql;