Comments for Structured Data http://structureddata.org Data, Databases, Performance & Scalability Sun, 13 May 2012 01:52:50 -0400 hourly 1 http://wordpress.org/?v=3.3.2 Comment on What Are Your System Statistics? 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. ]]> Comment on Oracle 11g: Extended Statistics by Extended Stats « Oracle Scratchpad http://structureddata.org/2007/10/31/oracle-11g-extended-statistics/#comment-26480 Extended Stats « Oracle Scratchpad Wed, 11 Apr 2012 23:37:33 +0000 http://structureddata.org/2007/10/31/oracle-11g-extended-statistics/#comment-26480 [...] very keen on the 11g extended stats feature, but I’ve just discovered a critical weakness in one of the implementation details [...] [...] very keen on the 11g extended stats feature, but I’ve just discovered a critical weakness in one of the implementation details [...]

]]> Comment on What Are Your System Statistics? 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
]]> Comment on The Core Performance Fundamentals Of Oracle Data Warehousing – Parallel Execution by Greg Rahn http://structureddata.org/2010/04/19/the-core-performance-fundamentals-of-oracle-data-warehousing-parallel-execution/#comment-26287 Greg Rahn Mon, 02 Apr 2012 05:26:44 +0000 http://structureddata.org/?p=818#comment-26287 I've updated the links. Thanks. I’ve updated the links. Thanks.

]]> Comment on The Core Performance Fundamentals Of Oracle Data Warehousing – Parallel Execution by adam http://structureddata.org/2010/04/19/the-core-performance-fundamentals-of-oracle-data-warehousing-parallel-execution/#comment-26281 adam Sun, 01 Apr 2012 22:48:30 +0000 http://structureddata.org/?p=818#comment-26281 Could you please correct the links mentioned at the bottom of the page, now error 404 not found is returned. Could you please correct the links mentioned at the bottom of the page, now error 404 not found is returned.

]]> Comment on Visualizing Active Session History (ASH) Data With R by Greg Rahn http://structureddata.org/2011/12/20/visualizing-active-session-history-ash-data-with-r/#comment-26083 Greg Rahn Sat, 17 Mar 2012 00:23:25 +0000 http://structureddata.org/?p=1684#comment-26083 Yuri- I'm aware of this, as it was stated in the first paragraph: "often times the cause for longer log file sync times is related to longer log file parallel write times." Do note though, that the data collection and analysis was necessary to prove this was indeed that case because the entry point to troubleshooting this was the observation of long log file syncs. Thanks for the pointer to the note. Yuri-

I’m aware of this, as it was stated in the first paragraph: “often times the cause for longer log file sync times is related to longer log file parallel write times.” Do note though, that the data collection and analysis was necessary to prove this was indeed that case because the entry point to troubleshooting this was the observation of long log file syncs.

Thanks for the pointer to the note.

]]> Comment on Visualizing Active Session History (ASH) Data With R by Kyle Hailey http://structureddata.org/2011/12/20/visualizing-active-session-history-ash-data-with-r/#comment-26080 Kyle Hailey Fri, 16 Mar 2012 18:35:40 +0000 http://structureddata.org/?p=1684#comment-26080 Here is a free ASH viewer called ASHMON I wrote some years ago in TCL/TK (runs on windows or LINUX as a fat client). http://ashmasters.com/ash-tools/ It will by default read v$active_session_history, but if you install S-ASH and log into ASHMON as the S-ASH owner, it will read S-ASH tables see http://ashmasters.com/ash-simulation/ http://oracleprof.blogspot.com/2011/11/new-release-of-s-ash-v23.html SASH obviates the need for the diagnostics pack license and allows it to run on standard edition and version 9 (as well as probably 7 and 8 though I haven't tried) For a pay for tool that is an ASH simulator (ie no diagnostics pack license, runs on v9 etc and runs on DB2, Sybase and SQL Server) there is "DB Optimizer" from Embarcadero. Cool thing is it saves the data to flat file that can be mailed and shared between people analyzing the data. (not to mention DB Optimizer comes with Visual SQL Tuning (VST). For another pay for tool lab128 is super fast and cheaper than DB Optimizer but only works on Oracle and has no sql tuning but it's fast. Did I say it's fast? Currently I'm interested in web interfaces to data, so set up a jquery and highcharts version here: http://dboptimizer.com/2011/10/31/w-ash-web-enabled-ash/ - Kyle Hailey Here is a free ASH viewer called ASHMON I wrote some years ago in TCL/TK (runs on windows or LINUX as a fat client).
http://ashmasters.com/ash-tools/
It will by default read v$active_session_history, but if you install S-ASH and log into ASHMON as the S-ASH owner, it will read S-ASH tables
see
http://ashmasters.com/ash-simulation/
http://oracleprof.blogspot.com/2011/11/new-release-of-s-ash-v23.html
SASH obviates the need for the diagnostics pack license and allows it to run on standard edition and version 9 (as well as probably 7 and 8 though I haven’t tried)

For a pay for tool that is an ASH simulator (ie no diagnostics pack license, runs on v9 etc and runs on DB2, Sybase and SQL Server) there is “DB Optimizer” from Embarcadero. Cool thing is it saves the data to flat file that can be mailed and shared between people analyzing the data. (not to mention DB Optimizer comes with Visual SQL Tuning (VST).

For another pay for tool lab128 is super fast and cheaper than DB Optimizer but only works on Oracle and has no sql tuning but it’s fast. Did I say it’s fast?

Currently I’m interested in web interfaces to data, so set up a jquery and highcharts version here:
http://dboptimizer.com/2011/10/31/w-ash-web-enabled-ash/

- Kyle Hailey

]]> Comment on Visualizing Active Session History (ASH) Data With R by Yuri van Buren http://structureddata.org/2011/12/20/visualizing-active-session-history-ash-data-with-r/#comment-26076 Yuri van Buren Fri, 16 Mar 2012 12:58:52 +0000 http://structureddata.org/?p=1684#comment-26076 Hi Greg, T think you have to read the following support note: Troubleshooting: log file sync' Waits [ID 1376916.1] Basically it says that, the log file parallel write is part of the log file sync operation, so Yes they are correlated. If you're log file parallel write is close to the log file sync times, the time spend is on IO writes. If log file parallel write is very small compared to log file sync you loose time in communication e.g. in doing many small commits; Regards, Yuri. Hi Greg,

T think you have to read the following support note:
Troubleshooting: log file sync’ Waits [ID 1376916.1]

Basically it says that, the log file parallel write is part of the log file sync operation, so Yes they are correlated.

If you’re log file parallel write is close to the log file sync times, the time spend is on IO writes. If log file parallel write is very small compared to log file sync you loose time in communication e.g. in doing many small commits;

Regards,

Yuri.

]]> Comment on Choosing An Optimal Stats Gathering Strategy by Greg Rahn http://structureddata.org/2008/03/26/choosing-an-optimal-stats-gathering-strategy/#comment-25995 Greg Rahn Fri, 09 Mar 2012 19:54:22 +0000 http://structureddata.org/2008/03/26/choosing-an-optimal-stats-gathering-strategy/#comment-25995 What version? Define "best"? In 11g, the defaults are the best place to start: dbms_stats.gather_table_stats('owner','table_name'); What version?
Define “best”?

In 11g, the defaults are the best place to start:
dbms_stats.gather_table_stats(‘owner’,'table_name’);

]]> Comment on DBMS_STATS, METHOD_OPT and FOR ALL INDEXED COLUMNS by Greg Rahn http://structureddata.org/2008/10/14/dbms_stats-method_opt-and-for-all-indexed-columns/#comment-25994 Greg Rahn Fri, 09 Mar 2012 19:52:29 +0000 http://structureddata.org/?p=190#comment-25994 I'd suggest opening up the documentation where it is discussed: http://docs.oracle.com/cd/E11882_01/appdev.112/e25788/d_stats.htm#r4c1-t43 I’d suggest opening up the documentation where it is discussed:
http://docs.oracle.com/cd/E11882_01/appdev.112/e25788/d_stats.htm#r4c1-t43

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