SAP Extended Segments Memory (ES)

 

SAP Extended Segments Memory (ES):

              SAP Extended segment memory (ES) forms the basis for extended memory (EM) and global extended memory (EG). The ES consists of a limited number of segments located next to each other and can be accessed by all work processes of an application server instance (AS instance). An ES segment consists of one or more ES blocks that are all the same size. The size of the blocks is configured in the profile parameter em/blocksize KB. The default value is 4 MB. When a user context requests a memory area from the EM, one or more blocks are allocated to the EM from the ES The ES blocks are stored in specific shared memory segments in the operating system. These segments are exclusively reserved for ES memory. How ES memory and therefore EM memory are implemented depends on the underlying operating system. 

Reference:

1. help.sap.com 
2. SAP Notes 
3. Linkedin