Patent ID: 6944635

Claim:
A method for file deletion and recovery against system failures in a database management system, the method comprising the steps of: (a) deleting files listed in a pending action list during a transaction commit process and writing a non-atomic operation including file deletion into a log as an atomic operation; and (b) recovering uncompleted file deletion during restart recovery by using the log, wherein the step (b) comprises the steps of: (b1) processing restart analysis including search of the uncompleted file deletion; (b2) processing restart undo including undo of the uncompleted file deletion; and (b3) performing the uncompleted file deletion, wherein the step (b1) comprises the steps of: (b11) if analysis is performed by reading a commit log record from a last checkpoint location, adding a file identifier list included in the log record into a transaction table as a corresponding transaction item; and (b12) if analysis is performed by reading a file delete log record from the last check point location, deleting a file identifier stored in the log record from a corresponding transaction item of the transaction table.