/* DISABLE NEW CONNECTIONS */
ALTER DATABASE <SOURCE_DB> WITH ALLOW_CONNECTIONS false;
-- or ALTER DATABASE moja_baza CONNECTION LIMIT 0;
/* KILL ALL EXISTING CONNECTION FROM ORIGINAL DB (sourcedb)*/
SELECT pg_terminate_backend(pg_stat_activity.pid) FROM pg_stat_activity
WHERE pg_stat_activity.datname = 'SOURCE_DB' AND pid <> pg_backend_pid();
/* do administaration task in example rename drop clone db*/
/* ENABLE NEW CONNECTIONS */
ALTER DATABASE <SOURCE_DB> WITH ALLOW_CONNECTIONS true;
ALTER DATABASE name RENAME TO new_name;
DROP DATABASE <dbname> WITH (FORCE);
/* CLONE DATABASE TO NEW ONE(TARGET_DB) */
/* CREATE DATABASE [Database to create] WITH TEMPLATE [Database to copy] OWNER [Your username]; */
CREATE DATABASE TARGET_DB WITH TEMPLATE SOURCE_DB OWNER USER_DB;