Re: Smon and dmt woes

From: Yong Huang <>
Date: Thu, 10 Jul 2008 08:25:21 -0700 (PDT)
Message-ID: <>

> Date: Wed, 9 Jul 2008 21:41:49 -0400
> From: rjamya <>
> Subject: Smon and dmt woes
> Hi all,
> 9206 db, i have a (relatively) big tablespaces consists of 42 datafiles
> totalling over 350GB in dictionary managed mode. i need to drop it, and
> recreate it as lmt with different size. All objects in that TS have been
> exported, now smon is trying to coalesce the free space for few hours.
> I tried setting event 10269 using alter system since i can't bounce the db
> (it is actively being used). Is ther eanother way to instruct smon to either
> finish the work quickly or stop working on it? This is because i already
> issued 'alter database datafile ... offline drop' for all datafiles in this
> TS hoping smon will ignore these and i can drop the ts quickly, but smon
> isn't giving up.
> I also did 'alter tablespace ... storage (pctincrease 0)' on all dmt
> tablespaces in vein hope that smon will ignore those for coalescing, but
> nothing works. Smon still has the ST lock that it won't give up. Other 12
> tablespaces are lmt and 12 more tablespaces that are dmt in this db.
> Any other ideas on how i can drop this tablespace quickly?
> Thanks in advance
> -----
> Best regards
> Raj


The "alter system set events '10269'..." command probably only works for new sessions. Since SMON is a background process you can't relaunch, this won't work. Try oradebug setxxxpid <smon pid>, and set the event there. Using OS pid is the easiest (change "xxx" to "os").

Once you set it, you can also confirm it by oradebug dump events 1 and check the trace file for the event number under Evt# column.

Yong Huang       

Received on Thu Jul 10 2008 - 10:25:21 CDT

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