Re: Can datafile be resized while instance is open?

From: Dean <>
Date: Mon, 25 Apr 2011 14:39:44 -0700 (PDT)
Message-ID: <>

On Apr 15, 11:33 am, joel garry <> wrote:
> On Apr 15, 9:48 am, Dean <> wrote:
> > Hi, I am a newbie administrator.  Is it safe to alter datafile size
> > while database is open?
> > I need to free up disk space of our database. I found scripts online
> > to calculate high water mark of extents and resize the datafile
> > accordingly.
> > What I am not sure if I could execute sqls like "alter database
> > datafile 'E:\ORACLE\PRODUCT\10.2.0\ORADATA\DB05\TL30.dbf' resize
> > 108m;" while database is online and open?
> > If not, what would be the proper procedures to take before executing
> > the alter sqls?
> > Thanks,
> > Dean
> Decades ago, it was a dangerous operation, but now it is solid as a
> rock.  Oracle will give you an error if it finds data above where you
> are trying to resize it to.
> Be wary of scripts from online, they may be out of date or wrong,
> examine them carefully and understand what they do.  There are
> multiple high water marks these days.
> dbconsole has a tablespace map option, it lets you look at the
> tablespace with colored segments, and you can find out the segment
> name by hovering the mouse over it.  Compare this to what the scripts
> tell you.  You have to look carefully to see where each datafile ends
> in this display.  See
> You should of course have a test database where you can try things.
> jg
> --
> is bogus.
> "I'm not that crazy."

Thanks Joel. Reclaiming Unused Space is very useful link. Dean Received on Mon Apr 25 2011 - 16:39:44 CDT

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