Patent ID: 8290928

Claim:
A system comprising: sitemap generator computer program instructions stored on one or more computer-readable storage devices that, when executed by one or more host computers, cause the one or more host computers to perform operations comprising: determining that a file has a previously stored version number; comparing (i) a current version number of the file to (ii) the previously stored version number of the file; generating a sitemap having an entry corresponding to the file if the current version number of the file is changed from the previously stored version number; and assigning a new last modified time as a last modified time value for the entry, if an actual last modified time of the file is not available; and search engine computer program instructions stored on one or more computer-readable storage devices that, when executed by one or more search engine computers, cause the one or more search engine computers to perform operations comprising: receiving the sitemap; determining that the entry was previously indexed at a time before the last modified time value; and accessing file information associated with the file and generating an updated index with the file information.