Archiving IDocs 
Use
IDocs are stored in several database tables. To keep these tables (and access times) small (to reduce the database load), without losing any IDocs, you can archive the IDocs at operating system level. These archives can then be moved to external storage media, such as disks (using ArchiveLink) or magnetic tape.
Prerequisites
In Customizing, you specify where the archive files are
located physically (that is, which storage media are used). For more
information, see 
Cross-Application
Components (CA) ® Archiving
Application Data ®
Introduction to Data Archiving ®
Customizing.
Activities
· Displaying or changing the archivable status
When can I archive IDocs?
· Archiving functions for IDocs
How are IDocs written to and read from archive files?
Make sure that you do not archive IDocs that may still be needed by the application.
When do I delete IDoc links (for example, with application documents?
· Archiving: Technical Realization
How does archiving work from a technical perspective?
See also:
General archiving information