Memory Placement Optimization (MPO) enables processors to have an affinity for the closes memory on Non-uniform Memory Access (NUMA) systems—the types of multisocket, large memory systems that are powered by SPARC processors and Oracle Solaris. Sun collaborated with Oracle to define and use the lgroup API, lgrp_init (3LGRP), and enable Oracle to optimize local versus remote access to the System Global Area (SGA, the database buffer cache) on NUMA machines. These optimizations were made default on Oracle 10g running on Sun NUMA based machines.
