2485428 - Oracle memory errors due to duplicate users on OS level

Oracle memory errors occur, like:

ORA-04030: out of process memory when trying to allocate 8392728 bytes (pga heap,redo read buffer)
ORA-04030: out of process memory when trying to allocate 8192 bytes (callheap,kdbmal allocation)
ORA-04030: out of process memory when trying to allocate 5240 bytes (callheap,items_dmlsrvRetryLogCtx)
ORA-04030: out of process memory when trying to allocate 64552 bytes (sort subheap,sort key)

SAP note 323816 is already applied, and orasid user shows correct limits for data, stack and memory:

host1:orasid 1> ulimit -a
time(seconds) unlimited
file(blocks) unlimited
data(kbytes) unlimited
stack(kbytes) unlimited
memory(kbytes) unlimited
coredump(blocks) 2097151
nofiles(descriptors) 8192
threads(per process) unlimited
processes(per user) unlimited

AIX operating system

ORA-04030, AIX, limits, out of process memory , KBA , BC-OP-AIX , IBM AIX , BC-DB-ORA , Oracle , Problem