This is the definition of the table that locks on insert:

CREATE TABLE CASH_CASHBOX_DAY_AMMOUNT
(
  CASHBOXID              INTEGER         NOT NULL,
  DATE_TIME              NUMERIC( 18, 0) NOT NULL,
  AMMOUNT                NUMERIC( 18, 0),
 CONSTRAINT PK_CASH_CASHBOX_DAY_AMMOUNT PRIMARY KEY (CASHBOXID, DATE_TIME)
);
ALTER TABLE CASH_CASHBOX_DAY_AMMOUNT ADD CONSTRAINT FK_CASH_CASHBOX_DAY_AMMOUNT
  FOREIGN KEY (CASHBOXID) REFERENCES CASH_CASHBOX
  (ID);


It is simple insert that just inserts single record. There is no triggers or generators. Primary key value is know before insert is executed.