Memory allocation 
In UNIX, if Roll memory gets full Heap memory is occupied and if heap memory gets full extended memory is used.
But
in windows it is different, after roll memory (ztta/roll_first) is
filled the work process uses Extended memory, after extended memory is
fill then remainder of roll memory ( ztta/roll_area – ztta/roll_first)
is used soon..
| Unix or Unix like systems | Windows |
| Roll Memory up to ztta/roll_area |
Roll Memory up to ztta/roll_first |
| | | \|/ |
| | \|/ |
| Heap Memory up to abap/heap_area_nondia or HM Exhaust |
Extended Memory up to ztta/roll_extension or EM Exhaust |
| | | \|/ |
| | \|/ |
| Extended Memory up to ztta/roll_extension or EM Exhaust |
Roll Memory Remainder of ztta/roll_area |
| | | \|/ |
|
| Heap Memory up to abap/heap_area_dia or HM Exhaust |