•Each page has place for LSN of most recent change to that page
•When a page is fetched into buffer, DBMS remembers latest LSN at that time
•Log itself is produced in buffer, and flushed to disk (appending to previously flushed parts) from time to time
•Important rules govern when buffer flushes can occur, relative to LSNs involved
–Sometimes a flush is forced (eg log flush forced when txn commits)