Memory Management

What is the use of profile paramater ztta/roll_area?

echtscorp Memory Management, Performance Tuning

The roll area is one of several memory areas, which satisfies the user requests of user programs. For technical reasons, however, the first 250 KB or so of a user context are always stored in the roll area, further data

– up to the roll area limit ztta/roll_first,
– in the extended memory, up to the limit ztta/roll_extension or if extended memory is exhausted, then
– again in the roll area, until the roll area is full, then
– in the local process area, up to the limit abap/heap_area_dia or abap/heap_area_total or until the address space or the
swap space is exhausted.

What is the use of profile paramater ztta/roll_area?

echtscorp Daily Administration, Memory Management

The value specifies the size of the roll area in bytes. The roll area is one of several memory areas, which satisfies the user requests of user programs. For technical reasons, however, the first 250 KB or so of a user context are always stored in the roll area, further data
– up to the roll area limit ztta/roll_first,
– in the extended memory, up to the limit ztta/roll_extension or if extended memory is exhausted, then
– again in the roll area, until the roll area is full, then
– in the local process area, up to the limit abap/heap_area_dia or abap/heap_area_total or until the address space or the
swap space is exhausted.

A part of this area (in the graphic, roll area 1) is allocated a user context at the beginning. Its size is defined in ztta/roll_first. The partial area is for the data that must be contained in the roll area. When a user context is changed, this data is “rolled” (copied) into and out of a work process. If ztta/roll_area is larger than ztta/roll_first, the additional space makes a second part available (roll area 2).

If the user context cannot be allocated more extended memory, this second part of the roll area is available for the dialog processes