Tip from Vlad Khorsun:
- add TranNum field to the all interesting tables
- fill this field in BEFORE INSERT OR UPDATE trigger using CURRENT_TRANSACTION value
- create special table like TranMarks(TranNum, TranMark)
- create sequence SeqTranMarks
- create ON COMMIT database trigger which will insert CURRENT_TRANSACTION and next value of sequence SeqTranMarks into TranMarks table
Now you have marked all records by transaction numbers and order of transaction's commits.