SAP SHM AREA FIXED PROPERTIES documentation, setup help and example usage

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Areas - Fixed Area Properties
Like basic properties , an area�s fixed properties can be only be changed by developers. When the fixed properties of an area are changed during operation, all area instances of the area are set to status expired. The area class does not have to be regenerated however.

Area Binding

The context that you specify for this property defines the visibility and lifetime of the instance's
area instance version . Possible contexts are:

application server

Area instance versions exist until the application server is shut down.

User session

Area instances exist until the last main session of the current user session ends. For area binding, every user logon to an AS ABAP counts individually. This also applies in particular when users log on via external interfaces such as RFC or ICF .

Top level transaction

The top level transaction is the first program in a call sequence. These area instances exist for as long as the ABAP memory assigned to a call sequence is loaded, in other words for as long as the internal session of the top level transaction is loaded.

Area Instance Versioning

This property defines whether there can be only one or several area instance versions of an area instance . Without versioning, there is only one version and the area instance is equivalent to this area instance version. With versioning, there can be several versions in different states , and an area instance is the quantity of all area instance versions with the same area instance name.
Without versioning, several readers from different internal sessions can access an area instance after it has been built. Write access is only possible if no read locks are in force. With versioning, a change lock can be set on an area instance that still has read locks.
The maximum number of versions of an area instance can be specified in the runtime-dependent area properties .