Re: LMTs

From: Niall Litchfield <>
Date: Tue, 11 Mar 2008 15:35:01 +0000
Message-ID: <>

Hi Shah,

I'm not convinced that I'm any more likely to run out of space if my alert is configured for 95% space usage or space used being within 5% of a calculated max value. I entirely agree that the more databases and the more tablespaces that you have the more difficult monitoring becomes - and the more attractive automating space management becomes, but I'm always going to have limits on

  1. filesystem size
  2. tape capacity
  3. backup window duration
  4. filesystem size on clone databases
  5. filesystem size on standbys

I'm sure there are others, which is why my personal preference is for fixed size datafiles and manual intervention. That said I *only* have 29 Oracle databases to monitor - though that does include 8 apps ones! I'm sure that others will have significantly more.

On Tue, Mar 11, 2008 at 12:32 PM, <> wrote:

> Niall,
> Only problem in setting autoextensible to off is if you run out space in
> middle of business day, some transactions will fail and rest will be the
> history......
> In large environment with many production database, with many more
> tablespaces it becomes difficult to monitor and maintain manually to make
> sure each tablespace has enough free space. I am using all tablespace
> autoextensible with fixed upper limit. I also have set up monitoring (patrol
> in my case) to send e-mail any time any tablespace is autoextended and
> mobile alert when actual size is within 5% of maxsize. If any tablespace has
> multiple datafile, I have kept only one datafile as autoextensible.
> Mayen Shah
> *"Niall Litchfield" <>*
> Sent by:
> Mar 11 2008 05:37 AM Please respond to
> To
> cc
> Subject
> Re: LMTs
> On Mon, Mar 10, 2008 at 2:30 PM, Joe Smith <**<>>
> wrote:
> DATAFILE '/FS/data_s01.dbf' size 2000m autoextend on next 1m maxsize
> 12000m,
> '/FS/data_s02.dbf' size 2000m autoextend on next 1m maxsize
> 12000m
> How do you control the size of LMTs.
> If I remove the "autoextend on next 1m" I can't use the "maxsize" keyword.
> How do I restrict the size of the datafiles for LMTs
> Hey Joe (always wanted to say that sorry)
> You have a choice. Either you want the datafiles to grow as needed and
> limit the total size to which they can grow - i.e to be autoextensible -
> in which case it makes sense that you need both the amount by which to grow
> each time and the absolute limit. Alternatively you know how big you want
> them to be and you just specify the fixed size for the datafile (no
> autoextension at all).
> I happen to prefer the latter - not least because it then becomes easy to
> tell when you are running out of space in a tablespace (how much free space
> is left), whereas when the datafiles are autoextensible it's very easily to
> miscalculate how full a tablespace is. I also like to change control space
> operations because they have an impact on clones, backups dataguard space
> requirements and so on. If you do prefer to let Oracle handle the growth
> then I'd suggest a rather larger next size than 1m. Once you get to 2gb of
> data every time you add 1mb more data you'll be growing the datafile which
> is a lot of growth operations. You'll also likely cause more filesystem
> fragmentation - though you might not care about that.
> --
> Niall Litchfield
> Oracle DBA*
> *** <>

Niall Litchfield
Oracle DBA

Received on Tue Mar 11 2008 - 10:35:01 CDT

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