MONITORING DOCUMENT CHANGES WITH PERSISTENT UPDATE SEQUENCE NUMBERS

A method and system for improved monitoring of document changes in a search engine by an indexing program. Once an indexing or other such monitoring program is halted, upon restart the monitoring program needs to update its own files and its indexes to reflect document changes that occurred while halted. A file system such as the Windows NT file system persistently logs document change information on disk in a monotonically increasing, uniquely-numbered persistent record, which further identifies the file that has changed. The method and system utilize the logged change information to efficiently maintain the indexes, and to rapidly update the indexes after a shutdown and subsequent restart.