Archive Page 3

Announcing The Oracle Real World Conference. Attending Oracle OpenWorld 2012? Great, It Happens To Coincide With This Great Event!

BLOG UPDATE 2012-09-21: The conference organizers had to dodge legal bullets from Oracle Corporation for using the word Oracle. So, the name of the conference changed to Oaktable World:

This is just a quick announcement about a great conference hosted by the good folks at Delphix, Miracle and Pythian.

Please visit the Oracle Real World website for session and venue information.

I’ll be offering a session called “SLOB Why, How and What’s It Got To Do With Exadata.” Attendees will learn how to put SLOB to use for their benefit. They might even learn something important about Exadata as an added bonus.

Please follow this link to the website to learn more.

Oracle Announces the World’s Second OLTP Machine. Public Disclosure Of Exadata Futures With Write-Back Flash Cache. That’s a Sneak Peek At OOW 2012 Big News.

The Enkitec Extreme Exadata Expo is well underway having just brought day 1 to a close with a keynote from Oracle’s Senior Vice President of Database Server Technology, Andy Mendelsohn.

Mr. Mendelson ended his presentation with a slide of futures for Exadata. Frits Hoogland tweeted the slide here.

I too was listening in on the presentation as a virtual attendee. I heard Mr. Mendelsohn state that the features fall into the “within 12 months” category. I suppose that means coinciding with Oracle Database 12.2 (note, dot-2). I could certainly be wrong on that matter though. Perhaps 12.1. We’ll see.

Of the items on the list I’d say the most interesting was the “Flash for all writes” item. The bullet point is enhanced with a pledge of 10x more writes for write-heavy OLTP. I knew of this feature and its eventual release, but now the information is public.

As my many posts on the matter attest, I have been critical of Oracle referring to Exadata as the “World’s First OLTP Machine” simply because it has read-cache. OLTP requires the scaling of writes along with reads. However, according to Oracle’s Exadata datasheets, the “World’s First OLTP Machine” is currently capable of 1.5 million read IOPS in a full-rack X2 configuration but only 50,000 gross random writes. With normal ASM redundancy the gross is reduced to a net WIOPS capacity of approximately 25,000 or a read:write ratio of 60:1. Many users feel compelled to use ASM high redundancy for reasons outside the scope of this post.

An increase in 10x would be 500,000 WIOPS (gross) which, being a write-back cache, will have to be de-staged back to spinning media at some point.

It will be interesting to see how this feature plays out. On first glance it would appear as though the goal is to support a read:write ratio of 6:1 which is drastically better than the World’s First OLTP Machine. If the World’s Second OLTP Machine can handle the de-staging from cache back to spinning media I’ll say kudos. Until we know, we can only guess.

Personally, I’m putting my bets on completely non-mechanical approaches for solving write-intensive OLTP problems. That’s another way of saying total flash storage.  However, I’d also stack up auto-tiering (e.g., EMC FAST) against this approach because the de-staging requirement is reduced as blocks are promoted to Enterprise Flash Drives. I have not performed any benchmark to back that viewpoint…but then I suspect a feature intended to see light of day “within 12 months” is getting much benchmark action within Oracle development either. There again, I could be wrong because I no longer work there.

What Are People Buying This Stuff For?
Since the vast majority of Exadata sales are quarter-rack configurations deployed for applications other than Data Warehousing I think Oracle is focusing on the correct weaknesses.

If you’re interested, I spoke of closely related topics in my recent interview in the August edition of the Northern California Oracle User Groups journal.

Finally, if you haven’t seen my video presentations on the fundamental architectural reasons Exadata is inferior to other solutions in the marketplace for the DW/BI/Analytics use case, I recommend you give them a viewing. Doing so might help you understand why Oracle sells more Exadata for use cases other than DW/BI and, in turn, why they focus on features that have nothing to do with that use case–like write-back flash cache.

My Interview In The Latest Quarterly Journal Of Northern California Oracle Users Group

This is just a quick blog entry to invite you to get a copy of the latest quarterly journal of Northern California Oracle Users Group. The Editor, Iggy Fernandez, interviewed me on a wide range of topics. The article begins on page 4.

Please click on the following link:

The following is a screenshot of the magazine cover and following that is a list of the questions posed to me in the interview.

Interview questions:

Is hardware the new software? Why bother with indexing,
clustering, partitioning, and sharding (not to mention application
design) if hardware keeps getting bigger and faster
and cheaper every day. Can we just “load and go?”

You were an architect in Oracle’s Exadata development organization.
With all the excitement about Exadata in the Oracle
community, what motivated you to leave?

You’ve been referring to it as “Exaggerdata.” Why so harsh?
You’ve got to admit that there’s plenty of secret sauce under
the covers.

“Do-it-yourself Exadata-level performance?” Really? We’re
all ears.

Are TPC benchmarks relevant today?

Where do you stand in the “Battle Against Any Raid Five

Can NAS match the performance of SAN? Can SAN match
the performance of locally attached storage

As a long-time NetApp fan, I like to stay in my comfort zone
but perhaps I’m biased. Does NetApp still offer anything that
the other NAS vendors (such as EMC) don’t?

Do we need yet another “silly little Oracle benchmark”?

Do you recommend that I use ASM? I worry that a sleepy
system administrator will unplug my disks someday because
“there were no files on them.” I do like to have my files where
I can count them every day!

Do you have an opinion on the NoSQL movement? Will the
relational mothership ever catch up with the speedboats?

My management is pushing me to take my databases virtual.
I can appreciate the advantages (such as elasticity) of virtualization,
but I’m not so sure about performance. Also, I cannot
rely on guest O/S statistics. Is it just the Luddite in me? Can
you help me push back on my management?

I like the Oracle Database Appliance (ODA) because RAC
raises the bar higher than most IT organizations can handle,
and ODA lowers it. What would you improve about the ODA
if you had a wizard wand?

Is NoCOUG a dinosaur, a venerable relic of the pre-information
age that has outlasted its usefulness?

SLOB Is Not An Unrealistic Platform Performance Measurement Tool – Part III. Calibrate, What?

Parts I an II of this series can be found here and here.

My previous installments in this series delved into how Orion does not interact with the operating system in any way similar to a database instance. This is a quick blog entry about CALIBRATE in that same vein.
On a system with 32 logical CPUs (e.g., 2s8c16t) we see CALIBRATE spawn off 32 background processes called ora_cs* such as the following ps(1) output screenshot:

I picked one of the processes and straced it to reveal the fact that CALIBRATE uses several processes each performing large-batch asynchronous I/O to do its job:

This should be a revelation to the purists out there. In my assessment I think CALIBRATE may even deviate worse from the goal of mimicking instance I/O than does Orion!
Nobody really cares about platforms though. So this is one of those “for what it’s worth” posts

Expert Oracle Exadata (Apress) Translated Into Chinese


Kerry Osborne has a short post to point out that the last book I worked on has been translated into Chinese.  The photo of the book cover looks pretty cool…if only I could read anything except for our names and a few stray English words :-)

This book is a must-read for anyone that wants to cut beyond the hype and actually learn Exadata.


Fault Injection Testing. Spurious Space Depletion? Sure, Why Not?

When file systems run out of space bad things happen. We like to investigate what those “bad things” are but to do so we have to create artificially small installation directories and run CPU-intensive programs to deplete the remaining space. There is a better way on modern Linux systems.

If you should find yourself performing Linux platform fault-injection testing you might care to add spurious space free failures. The fallocate() routine immediately allocates the specified amount of file system space to an open file.  It might be interesting to inject random space depletion in such areas as Oracle Clusterware (Grid Infrastructure) installation directories or application logging directories. Could a node ejection occur if all file system space immediately disappeared? What would that look like on the survivors? What happens if large swaths of space disappear and reappear? Be creative with your destructive tendencies and find out!


#include <asm/unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

int main(int argc, char *argv[])
long int sz;
char *fname;
int ret,fd;

if (argc != 3)
fprintf(stderr, "usage: %s file new-size-in-gigabytes\n", argv[0]);

fname = argv[1];
sz   = atol(argv[2]);

if ((ret = (fd = open(fname, O_RDWR | O_CREAT | O_EXCL, 0666)))  == -1 ) {

if ( (ret = fallocate( fd, 0, (loff_t)0, (loff_t)sz * 1024 * 1024 * 1024 )) != 0 ){
perror ("fallocate");
unlink( fname );

return ret;




# cc fast_alloc.c
# ./a.out
usage: ./a.out file new-size-in-gigabytes
# df -h .
Filesystem Size Used Avail Use% Mounted on
/dev/sdc 2.7T 1.6T 1.2T 57% /data1
# time ./a.out bigfile 512
real 0m1.875s
user 0m0.000s
sys 0m0.730s
# du -h bigfile
513G bigfile
# rm -f bigfile
# ./a.out bigfile 512
# ls -l bigfile
-rw-r--r-- 1 root root 549755813888 Jul 1 09:48 bigfile

Putting SLOB (The Silly Little Oracle Benchmark) To Use For Knowledge Sake!

This is just a short blog entry here to refer folks interested in SLOB to the following links:

About SLOB:  Introducing SLOB – The Silly Little Oracle Benchmark

EMC Employee Disclaimer

The opinions and interests expressed on EMC employee blogs are the employees' own and do not necessarily represent EMC's positions, strategies or views. EMC makes no representation or warranties about employee blogs or the accuracy or reliability of such blogs. When you access employee blogs, even though they may contain the EMC logo and content regarding EMC products and services, employee blogs are independent of EMC and EMC does not control their content or operation. In addition, a link to a blog does not mean that EMC endorses that blog or has responsibility for its content or use.

This disclaimer was put into place on March 23, 2011.

Enter your email address to follow this blog and receive notifications of new posts by email.

Join 1,935 other followers

Oracle ACE Program Status

Click It

website metrics

Fond Memories


All content is © Kevin Closson and "Kevin Closson's Blog: Platforms, Databases, and Storage", 2006-2013. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Kevin Closson and Kevin Closson's Blog: Platforms, Databases, and Storage with appropriate and specific direction to the original content.


Get every new post delivered to your Inbox.

Join 1,935 other followers