Re: Tablespace Usage and Performance

From: DA Morgan <>
Date: Mon, 10 Nov 2008 08:54:34 -0800
Message-ID: <>

Robert Klemme wrote:
> On 08.11.2008 21:48, DA Morgan wrote:

>> Robert Klemme wrote:
>>> On 08.11.2008 02:49, DA Morgan wrote:
>>>> Dereck L. Dietz wrote:
>>>>> Oracle 10g
>>>>> Windows 2003 Server
>>>>> I have someone who made the following statement:
>>>>> "any time a tablespace is > 85% [ of capacity ] we experience 
>>>>> performance degragation".
>>>>> Is there any validity in that or not?
>>>>> Thanks
>>>> Not!
>>> Hmm, I lean more towards Joel.  After all, the statement is just an 
>>> observation, which we can't really question.  The interesting bit is 
>>> to find out what caused this observation.  There may be a common root 
>>> for both phenomena (for example, heavy insert activity at end of 
>>> month just before old data is purged, leading to tablespaces filling 
>>> up AND queries being slow).  But of course, there is by far too many 
>>> detail to only start guessing about something like that.  We do not 
>>> even know what "performance degradation" means.  Is it queries, 
>>> inserts, backup etc.? Just one statement or multiple? ...
>> My point in the simplistic answer is that there may be other things
>> going on but there is no 1:1 relationship between available space
>> and performance. Could a lack of space mean that there are other
>> issues related to performance? Of course. But you can not draw a
>> straight line that corresponds with the question asked by the OP.

> I agree with regard to the straight line. I just felt the answer was
> probably a bit too simplistic in this case and was trying to avoid
> subsequent miscommunications e.g.
> "any time a tablespace is > 85% [ of capacity ] we experience
> performance degragation".
> "Can't be."
> "Are you kidding me? Look at these figures: " [EM pops up] "tablespace
> is full, query slow."
> ...
> And yes, I confess, I did enjoy the nitpicking. But I felt it could
> help speak out the unspoken so I did not resist the "temptation". :-)
> Kind regards
> robert

Works for me. <g>

Daniel A. Morgan
Oracle Ace Director & Instructor
University of Washington (replace x with u to respond)
Puget Sound Oracle Users Group
Received on Mon Nov 10 2008 - 10:54:34 CST

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