Comments on: What Are Your System Statistics? http://structureddata.org/2008/01/02/what-are-your-system-statistics/?utm_source=rss&utm_medium=rss&utm_campaign=what-are-your-system-statistics Data, Databases, Performance & Scalability Sun, 13 May 2012 01:52:50 -0400 hourly 1 http://wordpress.org/?v=3.3.2 By: Anonymous http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-28122 Anonymous Sun, 13 May 2012 01:52:50 +0000 http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-28122 <pre> SQL> select version from v$instance; VERSION ----------------- 11.2.0.2.0 SQL> select pname, pval1 from sys.aux_stats$ where sname = 'SYSSTATS_MAIN'; PNAME PVAL1 ------------------------------ ---------- CPUSPEEDNW 2946.74556 IOSEEKTIM 10 IOTFRSPEED 4096 SREADTIM MREADTIM CPUSPEED MBRC MAXTHR SLAVETHR 9 rows selected. </pre> SQL> select version from v$instance; VERSION ----------------- 11.2.0.2.0 SQL> select pname, pval1 from sys.aux_stats$ where sname = 'SYSSTATS_MAIN'; PNAME PVAL1 ------------------------------ ---------- CPUSPEEDNW 2946.74556 IOSEEKTIM 10 IOTFRSPEED 4096 SREADTIM MREADTIM CPUSPEED MBRC MAXTHR SLAVETHR 9 rows selected. ]]> By: Anonymous http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-26402 Anonymous Tue, 10 Apr 2012 20:52:06 +0000 http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-26402 Datawarehouse 15g sga, 55g ram, 12 cpu with 6 cores <pre> VERSION ----------------- 11.2.0.3.0 SNAME PNAME PVAL1 ------------------------------ ------------------------------ ---------- SYSSTATS_MAIN CPUSPEEDNW 508 SYSSTATS_MAIN IOSEEKTIM 5 SYSSTATS_MAIN IOTFRSPEED 48803 SYSSTATS_MAIN SREADTIM 1.003 SYSSTATS_MAIN MREADTIM 2.638 SYSSTATS_MAIN CPUSPEED 342 SYSSTATS_MAIN MBRC 5 SYSSTATS_MAIN MAXTHR 632393728 SYSSTATS_MAIN SLAVETHR 621568 </pre> Datawarehouse

15g sga, 55g ram, 12 cpu with 6 cores

VERSION
-----------------
11.2.0.3.0

SNAME                          PNAME                               PVAL1
------------------------------ ------------------------------ ----------
SYSSTATS_MAIN                  CPUSPEEDNW                            508
SYSSTATS_MAIN                  IOSEEKTIM                               5
SYSSTATS_MAIN                  IOTFRSPEED                          48803
SYSSTATS_MAIN                  SREADTIM                            1.003
SYSSTATS_MAIN                  MREADTIM                            2.638
SYSSTATS_MAIN                  CPUSPEED                              342
SYSSTATS_MAIN                  MBRC                                    5
SYSSTATS_MAIN                  MAXTHR                          632393728
SYSSTATS_MAIN                  SLAVETHR                           621568
]]> By: Dominic Brooks http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-17025 Dominic Brooks Tue, 22 Mar 2011 18:31:39 +0000 http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-17025 This seems to be bug 9842771 - "Wrong SREADTIM and MREADTIM statistics in AUX_STATS$" and described as "Unrealistic high values may be seen for SREADTIM and MREADTIM after gathering system statistics. Workaround Set the correct statistics manually using DBMS_STATS.SET_SYSTEM_STATS. " This seems to be bug 9842771 – “Wrong SREADTIM and MREADTIM statistics in AUX_STATS$”
and described as
“Unrealistic high values may be seen for SREADTIM and MREADTIM after
gathering system statistics.

Workaround
Set the correct statistics manually using DBMS_STATS.SET_SYSTEM_STATS.
“

]]> By: Dominic Brooks http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-17020 Dominic Brooks Tue, 22 Mar 2011 09:49:35 +0000 http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-17020 Sokrates - I'm glad I found your values. Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options <pre> SQL> select pname, pval1 from sys.aux_stats$ where sname = 'SYSSTATS_MAIN'; PNAME PVAL1 ------------------------------ ---------- CPUSPEEDNW 717 IOSEEKTIM 17 IOTFRSPEED 8707 SREADTIM 76000.74 MREADTIM 90191.077 CPUSPEED 745 MBRC 16 MAXTHR 188917760 SLAVETHR 509952 9 rows selected. SQL> </pre> Sokrates – I’m glad I found your values.

Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 – 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> select pname, pval1 from sys.aux_stats$ where sname = 'SYSSTATS_MAIN';

PNAME                               PVAL1
------------------------------ ----------
CPUSPEEDNW                            717
IOSEEKTIM                              17
IOTFRSPEED                           8707
SREADTIM                         76000.74
MREADTIM                        90191.077
CPUSPEED                              745
MBRC                                   16
MAXTHR                          188917760
SLAVETHR                           509952

9 rows selected.

SQL>
]]> By: Greg Rahn http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-13695 Greg Rahn Wed, 03 Nov 2010 04:02:03 +0000 http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-13695 @Sokrates I'm not aware of any changes. @Sokrates

I’m not aware of any changes.

]]> By: Sokrates http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-13679 Sokrates Tue, 02 Nov 2010 13:49:30 +0000 http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-13679 hmmm, upgraded to <pre> select version from v$instance; VERSION --------------------------------------------------- 11.2.0.2.0 collected NOWORKLOAD and 24-hour-WORKLOAD - system stats and got select pname, pval1 from sys.aux_stats$ where sname = 'SYSSTATS_MAIN'; PNAME PVAL1 ---------------- ---------- CPUSPEEDNW 2493 IOSEEKTIM 5 IOTFRSPEED 43707 SREADTIM 60207,956 MREADTIM 232679,32 CPUSPEED 2498 MBRC 16 MAXTHR 329274368 SLAVETHR 2839552 </pre> why are MREADTIM and SREADTIM so high ? Have they changed something ? (couldn't find something about any change, is it a bug ?) Greg, can you explain the MREATIM and SREADTIM values? hmmm, upgraded to

select version from v$instance;

VERSION
---------------------------------------------------
11.2.0.2.0

collected NOWORKLOAD and 24-hour-WORKLOAD - system stats and got

select pname, pval1 from sys.aux_stats$ where sname = 'SYSSTATS_MAIN';

PNAME		      PVAL1
---------------- ----------
CPUSPEEDNW	       2493
IOSEEKTIM	          5
IOTFRSPEED	      43707
SREADTIM	  60207,956
MREADTIM	  232679,32
CPUSPEED	       2498
MBRC		         16
MAXTHR		  329274368
SLAVETHR	    2839552

why are MREADTIM and SREADTIM so high ?
Have they changed something ?
(couldn’t find something about any change, is it a bug ?)

Greg, can you explain the MREATIM and SREADTIM values?

]]> By: Leigh Riffel http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-133 Leigh Riffel Fri, 04 Sep 2009 17:05:43 +0000 http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-133 <pre>SQL > SELECT version FROM v$instance; VERSION ----------------- 11.1.0.7.0 SQL > select pname, pval1 from sys.aux_stats$ where sname = 'SYSSTATS_MAIN'; PNAME PVAL1 ------------------------------ ---------- CPUSPEEDNW 2138.081 IOSEEKTIM 5.776 IOTFRSPEED 36145.224 SREADTIM 2.724 MREADTIM 3.547 CPUSPEED 2081 MBRC 31 MAXTHR 176668672 SLAVETHR 764928 9 rows selected. </pre> Windows 2008 on VMware ESX 3.5 on a two node cluster with 6 DBs. Each node has two dual core 2.66 GHz processors. The storage is an HP EVA with 35 disks shared among about two dozen systems. SQL > SELECT version FROM v$instance; VERSION ----------------- 11.1.0.7.0 SQL > select pname, pval1 from sys.aux_stats$ where sname = 'SYSSTATS_MAIN'; PNAME PVAL1 ------------------------------ ---------- CPUSPEEDNW 2138.081 IOSEEKTIM 5.776 IOTFRSPEED 36145.224 SREADTIM 2.724 MREADTIM 3.547 CPUSPEED 2081 MBRC 31 MAXTHR 176668672 SLAVETHR 764928 9 rows selected.

Windows 2008 on VMware ESX 3.5 on a two node cluster with 6 DBs. Each node has two dual core 2.66 GHz processors. The storage is an HP EVA with 35 disks shared among about two dozen systems.

]]> By: Nir Carasso http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-120 Nir Carasso Mon, 23 Mar 2009 12:38:25 +0000 http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-120 <a href="#comment-793" rel="nofollow">@Richa</a> I Richa's IOSEEKTIM parameter is very interesting -is it possible to know what type of storage is being used ? @Richa
I Richa’s IOSEEKTIM parameter is very interesting -is it possible to know what type of storage is being used ?

]]> By: Nir Carasso http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-132 Nir Carasso Mon, 23 Mar 2009 12:32:22 +0000 http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-132 <pre> SQL> select version from v$instance; VERSION ----------------- 10.2.0.1.0 SQL> select pname, pval1 from sys.aux_stats$ where sname = 'SYSSTATS_MAIN'; PNAME PVAL1 ------------------------------ ---------- CPUSPEED 1985 CPUSPEEDNW 1588.616 IOSEEKTIM 4.876 IOTFRSPEED 67665.085 MAXTHR 152200192 MBRC 33 MREADTIM 1.747 SLAVETHR 32113664 SREADTIM 2.021 9 rows selected. </pre> SQL> select version from v$instance; VERSION ----------------- 10.2.0.1.0 SQL> select pname, pval1 from sys.aux_stats$ where sname = 'SYSSTATS_MAIN'; PNAME PVAL1 ------------------------------ ---------- CPUSPEED 1985 CPUSPEEDNW 1588.616 IOSEEKTIM 4.876 IOTFRSPEED 67665.085 MAXTHR 152200192 MBRC 33 MREADTIM 1.747 SLAVETHR 32113664 SREADTIM 2.021 9 rows selected. ]]> By: Greg Rahn http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-128 Greg Rahn Wed, 28 May 2008 21:39:30 +0000 http://structureddata.org/2008/01/02/what-are-your-system-statistics/#comment-128 Chris- The largest I/O that Oracle can currently issue is 1MB. All modern operating systems support this (as far as I know) and some support even larger, though Oracle does not currently. The size of MBRC will depend mostly on the type of workload. If it is mostly index access, then it is likely to be on the smaller side (16 * 8k). If it is a data warehouse, then it very well may be on the upper bound, 1MB (128 * 8k). On a hybrid system, probably somewhere in between. I would be less concerned with the just MBRC size, and more concerned with the single and multi block read times (SREADTIM & MREADTIM), in relationship to a single block and the MBRC size. If these times are too close, and MBRC is on the larger side, it could possible cause the cost of a FTS to be artificially cheap. Chris-

The largest I/O that Oracle can currently issue is 1MB. All modern operating systems support this (as far as I know) and some support even larger, though Oracle does not currently.

The size of MBRC will depend mostly on the type of workload. If it is mostly index access, then it is likely to be on the smaller side (16 * 8k). If it is a data warehouse, then it very well may be on the upper bound, 1MB (128 * 8k). On a hybrid system, probably somewhere in between.

I would be less concerned with the just MBRC size, and more concerned with the single and multi block read times (SREADTIM & MREADTIM), in relationship to a single block and the MBRC size. If these times are too close, and MBRC is on the larger side, it could possible cause the cost of a FTS to be artificially cheap.

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