The upgrade technology from SAP has significantly changed over time. The first upgrade technology of SAP was based on so-called “Delta” upgrades. This technology was changed as of R/3 release 3.0A with the so-called “Repository Switch” technology. Later, SAP also introduced ICNV (Incremental Table Conversion) as an option to reduce downtime. Finally, the latest upgrade technology is called “System Switch.” All these innovations were introduced in order to improve the upgrade speed and to reduce the application downtime for the customer. All ABAP-based SAP applications make use of this new upgrade technology.
To get a good understanding of how an SAP upgrade works, we’ll first take a closer look at the techniques ...