The rebuild command is invoked from an Enterprise Developer command prompt.  Rebuild enables you to:

• Reorganize an indexed file
• Rebuild a corrupt indexed file
• Convert files from one organization to another
• Validate an indexed file

Problem:

A production system went down because of a power failure.  After the system came back up, users logged on and the application seemed to run normally, but the system administrator wondered whether indexed file corruption had occurred during the power failure.  The Rebuild command with the /f option can validate indexed files and report whether they are corrupted.  But can the rebuild command validate a file while the file is open in shared mode, in other words, currently being used by the application?

Resolution:

Yes, the rebuild command with the /f option can be used to validate indexed files that are currently open in shared mode.  But /f and /n are the only rebuild options that can be used in this circumstance; if you attempt to actually rebuild an indexed file that is currently open, the rebuild command will fail.