Oracle database internals by Riyaj

Discussions about Oracle performance tuning, RAC, Oracle internal & E-business suite.

Archive for the ‘Presentations’ Category

OOUG RAC day presentation files and scripts

Posted by Riyaj Shamsudeen on November 18, 2015

Thanks for coming to my presentations in RAC day at Dublin, Ohio. Please find the presentation files below. Hopefully, I will get video files and upload that here too.

OOUG presentation files and scripts

md5 checksum of the zip file is:


Posted in Oracle database internals, Performance tuning, Presentations, RAC | Tagged: , , | Leave a Comment »

RAC day with Ohio Oracle User Group

Posted by Riyaj Shamsudeen on October 22, 2015

I will be talking about RAC and performance in-depth, with lots of demos, in a RAC day training with Ohio Oracle User group on Nov 16,2015 Monday. Venue for the presentation is Dublin, Ohio.

Agenda for the day:

08:00a – 09:00: Registration / Breakfast

09:00a – 09:15: Announcements -Introduction of the speaker

09:15a – 10:30: Underpinning for Oracle RAC and Clusterware

10:30a – 10:45: Break

10:45a – 11:45: RAC cache fusion internals

11:45a – 01:00: Lunch

01:00p – 02:00: RAC Performance tuning Part 1 – Wait events and object tuning

02:00p – 02:15: Break

02:15p – 03:30: RAC performance tuning Part 2 – locks, library cache locks etc.

03:30p – 03:45: Member Announcements, Gift Drawings

Please RSVP to the co-ordinators so that you will have a seat :)


Posted in Oracle database internals, Performance tuning, Presentations, RAC | Tagged: , , , | 1 Comment »

Demos do fail.

Posted by Riyaj Shamsudeen on April 15, 2015

I am an ardent believer of “show me how it works” principle and usually, I have demos in my presentation. So, I was presenting “Tools for advanced debugging in Solaris and Linux” with demos in IOUG Collaborate 2015 in Las Vegas on April 13 and my souped-up laptop (with 32G of memory, SSD drives, and an high end video processor etc ) was not responding when I tried to access folder to open my presentation files.

Sometimes, demos do fail. At least, I managed to complete the demos with zero slides :-) Apologies to the audience for my R-rated rants about laptop issues.

You can download presentations files from the links below.



Posted in in-memory, inmemory, Performance tuning, Presentations | Tagged: , , , , , | Leave a Comment »

IOUG Collaborate 2015

Posted by Riyaj Shamsudeen on March 25, 2015

I will be presenting two topics in IOUG Collaborate 2015 in Vegas. Use the show planner and add my presentations to your schedule :)

Session #189: April 13 Monday 9:15 to 10:15AM Topic: Oracle Database 12c In-Memory Internals. Room Palm B

Session #145: April 13 Monday 12:45PM-1:45PM Topic: Tools and Techniques for Advanced Debugging in Solaris & Linux (mostly live demo). Room Palm B.

Posted in inmemory, Oracle database internals, Performance tuning, Presentations, RAC | Tagged: , , , , , | Leave a Comment »

RMOUG Training Days 2015

Posted by Riyaj Shamsudeen on January 19, 2015

I will be talking in Rocky Mountain Oracle User Group Training Days 2015(, with live demos (hopefully there will be no failures in the demo). My topics are:

Feb 17: Deep dive: 3:15PM to 5:15PM – RAC 12c optimization: I will discuss RAC global cache layer in detail with a few demos. You probably can’t find these deep Global Cache layer details anywhere else :)

Feb 19: Wednesday: 2:45PM to 3:45PM – Advanced UNIX tools: I will discuss both Solaris and Linux advanced tools to debug deep performance issues.

Feb 19: Wednesday: 12:15PM – 1:15PM – Exadata SIG panel with Alex Fatkulin.

Come to Denver. Come on, it won’t be cold ( I think :) )

Uploading presentation and scripts of the presentation files: RMOUG_2015_Riyaj_RAC_12c_optim files

Presentation files for Unix tools demos: RMOUG_2015_Riyaj_Unix_tools

Posted in Presentations, 11g, RAC, 12c | Tagged: , , , | 1 Comment »

In-memory pre-population speed

Posted by Riyaj Shamsudeen on October 6, 2014

While presenting at Oaktable World 2014 in San Fransisco, I discussed the in-memory pre-population speed and indicated that it takes about 30 minutes to 1 hour to load ~300GB of tables. Someone asked me “Why?” and that was a fair question. So, I profiled the in-memory pre-population at startup.

Profiling methods

I profiled all in-memory worker sessions using Tanel’s snapper script and also profiled the processes in OS using Linux perf tool with 99Hz sample rate. As there is no other activity in the database server, it is okay to sample everything in the server. Snapper output will indicate where the time is spent; if the time is spent executing in CPU, then the perf report output will tell us the function call stack executing at that CPU cycle. Data from these two profiling methods will help us to understand the root cause of slowness.

  1. @snapper.sql out,gather=stw 600 10 “select sid from v$session where program like ‘%W00%'”
  2. Perf tool : perf record -F 99 -u oracle -g sleep 3600

continue reading

Posted in 12c, in-memory, inmemory, Oracle database internals, Performance tuning, Presentations | Tagged: , , , , , , , | Leave a Comment »

Golden rules of RAC performance diagnostics

Posted by Riyaj Shamsudeen on March 20, 2014

After collaborating with many performance engineers in a RAC database, I have come to realize that there are common pattern among the (mis)diagnosis. This blog about discussing those issues. I talked about this in Hotsos 2014 conference also.

Golden rules

Here are the golden rules of RAC performance diagnostics. These rules may not apply general RAC configuration issues though.

  1. Beware of top event tunnel vision
  2. Eliminate infrastructure as an issue
  3. Identify problem-inducing instance
  4. Review send-side metrics also
  5. Use histograms, not just averages

Looks like, this may be better read as a document. So, please use the pdf files of the presentation and a paper. Presentation slide #10 shows indepth coverage on gc buffer busy* wait events. I will try to blog about that slide later (hopefully).

Golden rules of RAC diagnostics paper

Golden rules of rac diagnostics ppt

Scripts mentioned in the presentation can be downloaded here.


Posted in 11g, Performance tuning, Presentations, RAC | Tagged: , , , , , | 3 Comments »

Hotsos 2014

Posted by Riyaj Shamsudeen on February 25, 2014

I will be presenting in HOTSOS symposium 2014 discussing correct methods to diagnose RAC performance issues. Very surprisingly, even very senior performance engineers make mistakes in their analysis while reviewing RAC issues. Come to my presentation and learn the golden rules of RAC performance diagnostics.

Posted in 12c, Performance tuning, Presentations, RAC | Leave a Comment »

DOUG presentation on dbms_xplan

Posted by Riyaj Shamsudeen on October 22, 2012

Please join us at the DOUG (DALLAS ORACLE USERS GROUP) Oracle Database Forum meeting on Thursday, October 25, 2012 from 5 pm – 7 pm.
Presented by Riyaj Shamsudeen, OraInternals, & Sahil Thapar:

“Out with the old way, Enter dbms_xplan: A Swiss army knife for performance engineers”

Rough outline:
(i) Ability to query access path from memory, AWR repository
(ii) Ability to use cardinality feedback method to understand access plan issues. Few tips from a real world experience will be provided too.
(iii) Ability to understand issues with database links etc.
(iv) Options such as ADVANCED, ALLSTATS etc
(v) Why should you choose dbmx_xplan over tkprof+sql_trace combination?
(vi) Disadvantages of dbms_xplan and a quick introduction to dbms_monitor.

Refreshments sponsored by me :)

Update: Uploading the presentation pdf files. Enjoy :)


Posted in Performance tuning, Presentations | Tagged: , , , , | 5 Comments »

June 2012: Jonathan Lewis is coming to Dallas

Posted by Riyaj Shamsudeen on June 15, 2012

Quick note about Jonathan Lewis trip to Dallas: Jonathan Lewis will be presenting two day seminar on two topics, “Beating the Oracle Optimizer” (June 28) and “Troubleshooting and tuning” (June 29th).

The event will be held June 28-29, 2012 at SMU-in-Legacy in Plano, TX.

This is a must-attend event for experienced DBAs and Developers. Especially, if you are planning to upgrade your database/application in the near-future or if you are in the middle of an upgrade, you must attend these two seminars. This seminar series provide enormous value resolving complex Production performance issues.

Click Here for details.

Posted in Performance tuning, Presentations | Tagged: , | Leave a Comment »


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