Re: DBMS_STATS.GATHER_SYSTEM_STATS - learned something new

  • From: "Jonathan Lewis" <jonathan@xxxxxxxxxxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Fri, 12 Oct 2012 17:33:06 +0100

Expected behaviour.

Oracle flags whether or not it can use the workload stats 
(mreadtim/sreadtim/cpuspeed); if not then it applies the cpuspeednw, 
iotfrrate and whatever the seek time one is called.  If you gather workload 
stats (and they are self-consistent) then Oracle doesn't need to delete the 
noworkload stats - it's generally principle in Oracle, "don't clean up the 
mess if you don't need to, it's just more work".  (Or as Cary says, the 
fastest way to do something is to not do it at all - though I doubt if he 
says that immediately after telling his children to tidy their rooms ;)


Regards

Jonathan Lewis
http://jonathanlewis.wordpress.com/all_postings

Author: Oracle Core (Apress 2011)
http://www.apress.com/9781430239543

----- Original Message ----- 
From: <Christopher.Taylor2@xxxxxxxxxxxx>
To: <oracle-l@xxxxxxxxxxxxx>
Sent: Friday, October 12, 2012 4:37 PM
Subject: DBMS_STATS.GATHER_SYSTEM_STATS - learned something new


| Version 10.2.0.4
| I see that when you have _NOT_ executed 
DBMS_STATS.GATHER_SYSTEM_STATS(gathering_mode=>'NOWORKLOAD') at least once, 
and you run a regular 
dbms_Stats.gather_system_stats(gathering_mode=>'INTERVAL',interval=>&some_amount_of_minutes),
 
that Oracle does not update some of the SYSTEM STATS such as IOTFRSPEED.
|
| IOTFRSPEED stayed at 4096 when using the regular gather.  After using 
NOWORKLOAD it went to 38883.222, and then regathering stats using interval, 
it stays at 38883.222.
|
| Weird.
|
| Chris
|
| --
| //www.freelists.org/webpage/oracle-l
|
|
|
|
| -----
| No virus found in this message.
| Checked by AVG - www.avg.com
| Version: 2012.0.2221 / Virus Database: 2441/5327 - Release Date: 10/12/12
| 

--
//www.freelists.org/webpage/oracle-l


Other related posts: