There is a difference between the cross-transaction SAP memory and the transaction-specific ABAP memory.
The global SAP memory is available to a user during the entire duration of a terminal session. Its contents are retained across transaction boundaries as well as external and internal sessions. The SET PARAMETER and GET PARAMETER statements allow you to write to, or read from, the SAP memory.
Input fields on screens can be linked with parameters in the SAP memory, which allows you to preassign values to the input fields on initial screens.
With general screens, the linking takes place during the definition of the screen using the Screen Painter tool. When setting the field attributes of an input field, you can specify the ID of an SPA/GPA parameter in the Parameter-ID attribute. In the checkboxes SET Parameter and GET Parameter you can specify whether the screen field is filled with the value of the SPA/GPA parameter at the time of PBO or whether the SPA/GPA parameter is filled with the user input on the screen at the time of PAI.
With selection screens, the linking is carried out using the MEMORY
ID
addition to the
PARAMETERS or SELECT-OPTIONS
statement. If you specify an SPA/GPA parameter ID, when declaring a parameter or selection criterion, the relevant input field is linked with the parameter.
The local SAP memory is available to the user throughout a transaction, within which you can also call
other program units, for example using SUBMIT
or CALL TRANSACTION.
With SET PARAMETER
you write to both the global and the local SAP memory. If the global SAP memory is changed by an external
mode of the same user, the local SAP memory remains unchanged. This ensures that parameters set in the
frame of a transaction remain unchanged until the end of this transaction. The local SAP memory is deleted after the transaction is ended.
The contents of the ABAP memory are retained only during the lifetime of an external session (see also
Organization of Modularization Units). You can retain
or pass data across internal sessions. The
EXPORT TO MEMORY
and IMPORT FROM MEMORY
statements allow you to write data to, or read data from, the ABAP memory.
Please consult Data Area and Modularization Unit Organization documentation as well.
and
Memory Structures of an ABAP Program