· Repairing a corrupted index.
· Changes to crawl rules.
· Changes to iFilter and file-type mappings.
· Changes to the managed property search schema.
· Application of service packs and hot fixes (although you should read the documentations for these fixes to determine whether they require full crawls.)
· Re-indexing ASPX pages on SharePoint 3.0 or Microsoft Office SharePoint Server 2007 sites. The crawler cannot discover when ASPX pages in Windows SharePoint Services 3.0 or Microsoft Office SharePoint Server 2007 sites have changed. Because of this, incremental crawls do not re-index views or homepages when individual list items are deleted. Therefore you should periodically perform full crawls of SharePoint sites that contain ASPX files to ensure that these pages are re-indexed.
· When 100 consecutive incremental crawls fail for some reason.
· An SSP administrator stopped the previous crawl.
· A content database was restored.
· A full crawl of the site has never been done.
· When the change log retention period of a Windows SharePoint Services 3.0 Web application being crawled has been surpassed.
Richard Mueller edited Revision 3. Comment: Removed (en-US) from title
Craig Lussier edited Revision 2. Comment: added en-US to tags and title