>> Your assumption is wrong. The fixed SGA contains variables that are known at oracle compile time or point to structures in variable part. So the answer is that generally speaking, all x$ are in the variable part of the SGA. Also there may be multiple segments but they are contiguous in memory (not always the case), ... Anjo, does it really matter that the segments are not contiguous in memory? They should be contiguous in the address space of the process and that should be all that matters. No ? I've never seen any other port of Oracle than the one I worked on, but from my memory of the code, I can't image how Oracle would work at all with virtual address holes in the midst of the SGA. -- //www.freelists.org/webpage/oracle-l