SAP Memory Model on IBM i
In the SAP application server ABAP, shared memory is playing an important role in storing temporary application data. On IBM i, shared memory can be implemented in two different ways, which are controlled with profile parameter ES/TABLE. While ES/TABLE=UNIX_STD is the default and used to be faster in IBM i releases prior to IBM i 6.1, ES/TABLE=SHM_SEGS can be significantly faster in later releases on servers with a many processors. Switching to ES/TABLE=SHM_SEGS has prerequisites and requires adjustment of additional profile parameters. The attached presentation explains the prerequisites and parameter dependencies. You can also find this information in SAP Note 808607.