Oracle creates multiple shared memory segments despite SGA < SHMMAX

From: <ca111026_at_gmail.com>
Date: Thu, 5 Mar 2009 14:15:04 -0800 (PST)
Message-ID: <a7058461-e18a-4901-af98-a2122548fb84_at_e1g2000pra.googlegroups.com>

This is new installation of 10.2.0.4 on HP-UX 11.23 Itanium. HP-UX kernel parameter SHMMAX is 10G,
Oracle parameter SGA_MAX_SIZE set to 8G.

On startup Oracle creates 4 shared memory segments, size in bytes: 4064346112
4076863488
 488710144

        20480

Any idea why?

Yes I know that it *should* run OK with multiple shared memory segments,
and I am aware that it is normal to create segments with different size
(Metalink Note 15566.1). Still I would prefer to have one segment, not 4.

There is only one instance on this server, there is no other software that uses IPC (Tuxedo, etc), Oracle started immediatelly after server reboot.

The only kernel parameter set to 4G is MAXDSIZ_64BIT. As far as I understand
it shouldn't affect sizing of shared memory segments. Received on Thu Mar 05 2009 - 16:15:04 CST