Space reserved for user context in work processes
This parameter defines the size (in MB) of the address space that isprovided for the memory class "extended memory" in a work process. Thisalso defines the total maximum size of extended global memory andextended memory for a single user context. The value is only relevant onoperating systems that implement extended memory with mapped files, thatis, operating systems that map extended memory in the address space ofthe process (Microsoft Windows NT, Linux, AS/400). A targeted setting ofthe value is required to make optimal use of the limited address spaceon 32 bit platforms or on 64 bit platforms if an extremely large amountof extended global memory or extremely large user contexts are required.The size of the address space for a process under 32 bit MicrosoftWindows NT is 2 GB.
Rule of thumb
Code + roll area + total (buffers) + em/address_space_MB <(><<)> 2GB
100MB+ 10MB + ? + ?
512 for 32-bit
4GB or 8GB for 64-bit
Who is allowed
Limitation for os
Applies only for Microsoft Windows NT and Linux
Limitation for db
Approximately 512 to 1500 for 32 bit or if required for 64 bit
512 to 1500