Re: impdp very very long ...

From: Mladen Gogala <>
Date: Wed, 23 Jul 2008 08:12:59 +0200 (CEST)
Message-ID: <g66i5b$51l$>

On Tue, 22 Jul 2008 09:34:22 +0200, Giganews wrote:

> I don't know WHAT it is waiting for, but I know WHO is waiting: at some
> point in the alert log, I get several messages MMNL absent for 1205
> secs; Foregrounds taking over MMNL absent for 2856 secs; Foregrounds
> taking over etc.
> I found on Metalink that this might be a problem with the Undo
> tablespace datafile definition, when max size < initial size. This was
> probably the case in our system: we had set Initial Size to 1024000 KB,
> and max size to 1000 MB. I changed max size to 2 GB and the problem
> seems to be fixed. Yesterday, the procedure took about 90 minutes, which
> is a normal duration.
> pher

I would be most interested in the ML note that lead you to the conclusion about "MMNL absent" notes being caused by the undo tablespace. I found the following note: Note:567562.1
I will quote the most important part:


The Memory Monitor Light (MMNL) process is a new process in 10g which works with the Automatic Workload Repository new features (AWR) to write out full statistics buffers to disk as needed. These messages can be generated if you have the database in restricted mode. Sat May 10 02:28:03 2008
Starting ORACLE instance (restrict)
Sat May 10 03:37:39 2008
MMNL absent for 4159 secs; Foregrounds taking over Sat May 10 06:13:28 2008
MMNL absent for 13509 secs; Foregrounds taking over Sat May 10 06:42:35 2008
MMNL absent for 15256 secs; Foregrounds taking over Sat May 10 07:26:42 2008
MMNL absent for 17902 secs; Foregrounds taking over Sat May 10 10:32:08 2008
MMNL absent for 29029 secs; Foregrounds taking over Sat May 10 10:37:12 2008
MMNL absent for 29334 secs; Foregrounds taking over Sat May 10 11:38:47 2008
ALTER SYSTEM disable restricted session; Solution
Messages are informational only. They will stop once the database is no longer in restricted mode.

As for the "I don't know what is it waiting for", I believe that 10g might have
tables like V$SESSION_WAIT and V$SESSION_EVENT for that purpose.

Mladen Gogala
Received on Wed Jul 23 2008 - 01:12:59 CDT

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