Presentations

As the the Icelandic volcano ashes are clearing out and we finally have high hopes of flight home, I want to post the slides of the two presentations I did.

My first presentation was a double slot session about Oracle Clusterware internals. Presenting first thing in the morning on the first day is not easy at this event. Miracle Open World traditionally organized as 160% conference with 80% of technical content and 80% of networking and social interactions. Of course, the last 80% go deep into the night. Needless to say that 5am wake up call was tough — I had to craft few more slides to add some 11gR2 information and publish the first production of We Do Not Use TV Studio.

But I felt surprisingly well and fresh. The presentation itself was quite dynamic and all demos worked as planned except pausing OPROCD — 50/50 that eviction happens during my actions and it took me 10 time to repeat it. I couldn’t recall that I was lucky more than twice in a row until that session but… things happen. You can see the slides below for the reference. However, without the text and demos behind the slides, they are not very useful I’m afraid.

In RAC, every data block is mastered by an instance. Mastering a block simply means that master instance keeps track of the state of the block until the next reconfiguration event (due to instance restart or otherwise).

Hash to the master

These data blocks are mastered in block ranges. For example, range of blocks starting from file 10, block 1 through block 128 may be mastered by instance 1, blocks from file 10, block 129 through 256 are mastered by instance 2 etc. Of course, there are differences between various versions 10g, 11g etc, but Idea here is that block ranges are uniformly mastered between various instances so that Global cache grants are evenly distributed among the instances. Interestingly, length of the block range is 128 from 10g onwards (Julian Dyke mentioned that is 1089 in 9i, but I have not personally tested it). Of course, Support recommends you to unset db_file_multiblock_read_count which will be auto adjusted to 128 which means that Full block range can be read with fewer GC messages, I suppose. I digress.

Further, Michael Möller pointed out that this hash-algorithm is further optimized: The hash-algorithm used when initially computing the master node from the DBA, results in a “virtual master”, which is then translated to a real (online&open) master by a lookup table (the length of which is the maximum number of possible nodes (128 ?). This means that when one node goes off/on-line, RAC does NOT have to recalculate the hash for all blocks, but only distribute the new Hash-to-node table. (One can later visualize dynamic remastering as an additional lookup table between the hash value and node. This table also needs redistributing on node changes.)

Video fragments of my session posted at the end — read on.

I arrived at Omni Mandalay Hotel on Sunday evening with Dan Norris. I was flying through Chicago and it turned out that Dan was on the same flight and only few rows behind me. Small world.

Preparations for the conference were very chaotic on my part and, of course, I didn’t have either of my presentations ready. I was very stressed and getting sick as well — it looked like a complete disaster waiting to happen. I’d like to say that I was feeling like Doug Burns as he often managed to get sick just before a conference. Of course, I worked on my slides for the last few days as well as on the flight and presentation was slowly getting there but boy was I tired!

Just a quick announcements…

If you didn’t manage to attend my presentation, Oracle 11g ASM — The Evolution, during RMOUG or other conferences, you have a chance to see it online today. I’m doing it a web-cast at RAC SIG. It’s today, 4-Mar-10 at 12:00pm EST (9:00am PST).

RMOUG was over last week but I haven’t got back until earlier this week and I finally managed to clean up the backlog of things I missed so I could write the conference wrap up. After the RMOUG, I went skiing with a bunch of good friends and discovered a great skiing resort of Breckenridge. This is me at the peak 8 summit:
@ Breckenridge, Peak 8 Summit" title="Alex Gorbachev @ Breckenridge, Peak 8 Summit" width="358" height="332" class="alignnone size-full wp-image-8901" />

These were great times except one day with the questionable results of an experiment to find a recipe for the perfect hangover that I and Mogens Nørgaard have conducted. Well, the science does require sacrifices…

Back to the conference…

I have really enjoyed few technical sessions that I managed to attend. I want to mention couple that I liked especially. I managed to attend the full session by Robyn Sands about adopting variance to performance troubleshooting and performance acceptance — lots of interesting goodies. I have also enjoyed High Performance Oracle on NFS from Jeff Needham. Jeff has been instrumental helping me in number of projects and I think anybody who is thinking to run Oracle on NFS should attend Jeff’s session and learn “The Formula” covering all the basics of a successful Oracle on NFS storage stack.

Oracle ASM 11g Release 2 – The Evolution

Oracle Automatic Storage Management has proven to be one of the most widely adopted new features in Oracle Database 10g and it has been dramatically improved in the later 11g releases. This presentation will explain what changes are solved by ASM, how these challenges are solved, what barriers there are to ASM adoptions, and how 11g Release 2 addresses these barriers.

I shall say that the slides alone are not that helpful without my commentary but if you didn’t manage to attend it on one of the previous conferences, we will be releasing it as a webinar soon so stay tuned.

It is very disappointing to me that I had to cancel my trip to RMOUG training days. I am sick and was not able to catch the flight due to that.

But, I can always share my presentations here. I had two presentations planned in this training day and can be accessed as below:

Advanced RAC troubleshooting
Riyaj_Advanced_rac_troubleshooting_RMOUG_2010_doc
Riyaj_Advanced_rac_troubleshooting_RMOUG_2010_ppt

Why optimizer hates my sql
Riyaj_Why_optimizer_hates_my_sql_2010

RMOUG training days audience: Please accept my sincere apologies.

I will be presenting on two topics in HOTSOS’ 2010, an Oracle performance focused conference, in my home town Dallas, Texas. You can read about my presentation topics in HOTSOS’ 2010 Riyaj . This symposium is a valued conference for performance engineers, DBAs and developers who are interested to know learn about performance. There are many great speakers presenting in this conference and the main page for this conference is HOTSOS ’2010 . BTW, My friend Alex Gorbachev interviewed Gary Goodman and posted a video in his blog also.

Tanel Poder is conducting the HOTSOS training day this year. You can’t miss his training day and I heard that he is working on a MOTS (Mother Of all Tuning Script) and planning to release that in HOTSOS ’2010.

On behalf of the Dallasites, I invite you to visit Dallas and attend this great conference.

I wish you a Happy and prosperous New Year ’2010!

Well, it is that time of the year !

Few Presentations

I will be presenting two papers in Birmingham, UK Oracle User Group Technology conference . My sessions are :

1. Tuesday 10:55-11:55: Battle of the nodes: RAC Performance myths .


2. Wednesday 15:15-16:00: Advanced performance issues: A close encounter with real world performance issues .
   

I will upload new versions of these presentations in this blog, few days after the conference. See you in Birmingham.

Update: Papers and presentations can be downloaded following the links below:
1. Battle of the nodes RAC performance myths ppt

2. Battle of the nodes RAC performance myths doc

3. Close encounter with real world and odd perf issues ppt

If you live in Dallas area, there are two very important seminars coming up:

1. Tanel Poder is presenting his Advanced Oracle troubleshooting seminar on September 9-11, 2009. .
2. Jonathan Lewis presenting two day seminar cost based optimization and writing efficient SQL on Oct 28 and Oct 29 2009

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These two gentlemen needs no introduction. Tanel Poder is an expert in Oracle internals and Jonathan Lewis is a Guru in Cost based optimization and writing efficient SQL.

Tell them I sent ya

Update: I just heard from Tanel and he is unable to make it to Dallas this September. He is rescheduling his seminar and I can’t wait for his seminar. I will update this blog with his rescheduled dates.