https://blog.apatin.ru/p/postgres_logging_trigger/

create_function.sql

CREATE OR REPLACE FUNCTION change_trigger() RETURNS trigger AS $$
BEGIN
  IF TG_OP = 'INSERT'
    THEN
      INSERT INTO history (tabname, schemaname, operation, new_val, item_id)
      VALUES (TG_RELNAME, TG_TABLE_SCHEMA, TG_OP, row_to_json(NEW), NEW.id);
      RETURN NEW;
ELSIF TG_OP = 'UPDATE'
  THEN
    INSERT INTO history (tabname, schemaname, operation, new_val, old_val, item_id)
    VALUES (TG_RELNAME, TG_TABLE_SCHEMA, TG_OP, row_to_json(NEW), row_to_json(OLD), NEW.id);
    RETURN NEW;
  ELSIF TG_OP = 'DELETE'
    THEN
      INSERT INTO history (tabname, schemaname, operation, old_val, item_id)
      VALUES (TG_RELNAME, TG_TABLE_SCHEMA, TG_OP, row_to_json(OLD), OLD.id);
      RETURN OLD;
  END IF;
END;
$$ LANGUAGE 'plpgsql' SECURITY DEFINER;

create_table_history.sql

CREATE TABLE history (
    id          serial,
    tstamp      timestamp DEFAULT now(),
    schemaname  text,
    tabname     text,
    operation   text,
    who         text DEFAULT current_user,
    new_val     json,
    old_val     json,
    item_id     int8
);

create_trigger.sql

CREATE TRIGGER tablename_trigger BEFORE INSERT OR UPDATE OR DELETE ON tablename FOR EACH ROW EXECUTE PROCEDURE change_trigger();