Re: Windows: Virtual bytes considerably larger than SGA+PGA?

From: <bdbafh_at_gmail.com>
Date: 10 Jan 2006 08:36:47 -0800
Message-ID: <1136911007.093271.155700@f14g2000cwb.googlegroups.com>

Use the tool from SysInternals "pslist.exe" to determine the amount of virtual memory allocated under the oracle.exe process, e.g.:

C:\> pslist -m oracle

Its the virtual memory that is important here. The sga_max_size is thrown in terms of virtual memory at instance startup.
Other memory pools don't allocate memory under the oracle.exe process until they require it (e.g. pga_aggregate_target). As you can tell from your analysis, the pga_aggregate_target is not a hard limit and can be exceeded.
Also - each dedicated server session allocates private memory, even while using p_a_t.
How many simultaneous sessions are being supported? You might want to consider using the orastack.exe tool to reduce the per session memory allocation (with adequate testing of the application code).

Some of these docs haven't been updated for 9i R2, but are still largely valid:

RELATED DOCUMENTS: (Metalink)

Note:116076.1 Tackling ORA-4030 on WindowsNT

Note 28299.1 Windows NT Architecture Guide
Note 46001.1 Oracle and the Windows NT memory architecture
Note 46053.1 Windows NT Memory Architecture Overview

Look for the platform-specific tuning guide for your release.

btw - you will not see 3 * 1024 * 1024 * 1024 bytes of virtual memory under a process.
you just plain can't get there from here.

hth
-bdbafh Received on Tue Jan 10 2006 - 10:36:47 CST