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Re: Autoextend switch

From: Niall Litchfield <niall.litchfield_at_dial.pipex.com>
Date: Mon, 16 Jun 2003 21:39:25 +0100
Message-ID: <3eee2aa6$0$11380$cc9e4d1f@news.dial.pipex.com>


Hi

Have a look at OEM, since it comes for free. It should let you set up jobs to monitor space et al, and also to define fixit actions for when something boring, but predictable needs to be done (like add a datafile). It isn't in itself trouble free but it does (at least since 8.1.7) mostly work.

-- 
Niall Litchfield
Oracle DBA
Audit Commission UK
*****************************************
Please include version and platform
and SQL where applicable
It makes life easier and increases the
likelihood of a good answer
******************************************
"Gary" <rooty_hill2002_at_yahoo.com.au> wrote in message
news:171bd226.0306151744.1649e516_at_posting.google.com...
> "Niall Litchfield" <niall.litchfield_at_dial.pipex.com> wrote in message
news:<3ee97d56$0$11381$cc9e4d1f_at_news.dial.pipex.com>...

> > "Gary" <rooty_hill2002_at_yahoo.com.au> wrote in message
> > news:171bd226.0306122211.50ec871_at_posting.google.com...
> > > Hi!
> > >
> > > I was told technically it is not a good idea to switch on AUTOEXTEND
> > > for all tablespaces except for SYSTEM. Practically as a junior Oracle
> > > DBA I am really allured to switch it on for all tablespaces.
> > >
> > > Could anybody explain to me why AUTOEXTEND will cause fragmentation or
> > > I/O contention?
> >
> > My problems with autoextend are listed below
> >
> > 1. If something starts growing like topsy for some daft reason how are
you
> > going to know?
> > 2. What happens if you fill the disk?
> > 3. There are various bugs relating to datafile resizing on various
platforms
> > that can seriously harm your database.
> >
> > Autoextend can't cause fragmentation or IO contention so far as I can
see.
> > Different extent sizes cause fragmentation and frequently accessed
objects
> > or datafiles on the same disk cause IO contention. Neither of these
depend
> > on the datafile being set to autoextend.
> >
> > Setting the NEXT parameter smaller than the extent size of your objects
will
> > I believe cause unnecessary IO on at least 8.1.7 (i.e IIRC object
requests
> > 64mb next extent, autoextend is set NEXT 64k instead of NEXT 64m you
will
> > get 1024 extensions of the datafile instead of 1.)
> > > >
> > --
> > Niall Litchfield
> > Oracle DBA
> > Audit Commission UK
> > *****************************************
> > Please include version and platform
> > and SQL where applicable
> > It makes life easier and increases the
> > likelihood of a good answer
> > ******************************************
> > Thanks Niall. > > I work for 24*7 shop and we've got lots of backend batches. Looks like > I have to change the code to let the batches to handle some specific > error from Oralce in this case, although I as a Oracle DBA, am > supposed to monitor the space usage on daily base by using some > statistic packages of my own. > > I hope I get it right this time. > > Thanks again.
Received on Mon Jun 16 2003 - 15:39:25 CDT

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