Jonathan Lewis

I am finally getting around to finishing my four-part blog series on people who have had the most influence on my Oracle performance tuning work. The previous three people were Craig ShallahamerDon Burleson, and Cary Millsap. The last person is Jonathan Lewis. These four people, listed and blogged about in chronological order, had the most influence on my understanding of how to do Oracle database performance tuning. There are many other great (more...)

java.lang nullpointerexception While Installing 12.1.0.2 RAC Database Software

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I have an Oracle  12.1.0.2c cluster having following 5 nodes :

  • Hub Nodes : host01, host02, host03
  • Leaf nodes: host04 and host05

I wanted to install RAC database software on the 3 hub nodes i.e. host01, host02 and host03.

I invoked the OUI as oracle user (Owner of Database Home)

[oracle@host01 database_12_1_0_2]$ ./runInstaller

and chose the option to install RAC database software only on the 3 hub nodes.

After (more...)

Partially Applied Functions in JavaScript

First of all, what are partially applied functions? There’s a little bit of theory here. The concept of partially applying functions stems from the functional way of programming. There it’s tightly linked with a concept called currying. Currying says that every function can be written as a function with only one parameter. By currying and un-currying you can achieve this goal. If this sounds very hard and complex, do not fear, in essence it’s quite (more...)

Collaborate 2016 Oaktable World Sessions

Oaktable World Las Vegas is happening at Collaborate 2016! Many thanks to Tim Gorman, Alex Gorbachev and Mark Farnham for organizing!
Free Oaktable World t-shirts available at Delphix booth 1613 on Tuesday and at the Oaktable World talks on Wednesday. Also available at the Delphix booth is free copies of Mike Swing’s “the little r12.2.5 upgrade essentials for managers and tema members”. Mike will be doing Q&A at the Delphix booth Tuesday 1:15-2:00 and book (more...)

Inflexible Security (MailChimp fail)

Maybe I shouldn’t have written about flexible security, because I immediately starting hitting inflexible security, locking me out.

Today’s fail is courtesy of MailChimp.com, which I use for my newsletters. It’s OK that they decided they want a confirmation when I log on to my account from India, but it is not OK that they require a text message passcode with no other option.

I have my phone in flight mode, because I don’t (more...)

Log file parallel write wait graph

I got a chance to use my onewait Python based graph to help with a performance problem. I’m looking at slow write time from the log writer on Thursday mornings. Here is the graph with the database name erased:

log_file_parallel_write_waits

We are still trying to track down the source of the problem but there seems to be a backup on another system that runs at times that correspond to the spike in log file parallel write (more...)

Python DBA Graphs Github Repository

I decided to get rid of the Github repository that I had experimented with and to create a new one. The old one had a dump of all my SQL scripts but without any documentation. But, I have updated my Python graphing scripts a bit at a time and have had some recent value from these scripts in my Oracle database tuning work. So, I created a Github repository called PythonDBAGraphs. I think it will (more...)

Another SQL Profile to the rescue!

We have had problems with set of databases over the past few weeks. Our team does not support these databases, but my director asked me to help. These are 11.2.0.1 Windows 64 bit Oracle databases running on Windows 2008. The incident reports said that the systems stop working and that the main symptom was that the oracle.exe process uses all the CPU. They were bouncing the database server when they saw this behavior (more...)

Force OEM to Discover HA Systems

You know there’s a cluster and that means that an HA system exists, but OEM won’t discover it.  Of course that means that your RAC databases can’t be discovered either and all of this is making you cranky.  Take a deep breath.  We can fix this.

The agent can only recognize an HA system when it knows of the clusterware home.  For some reason the agents weren’t aware of the CRS_HOME on some of our (more...)

New APEX training in Vienna – APEX Debugging and Performance

Just a quick note: I’ll be holding a 1-day APEX training class on April 21st in Vienna, Austria.

In this training I’ll teach you how to debug your APEX applications, how to find problems and bugs and how to speed up your application.

Interested? Go here and sign up: http://www.aoug.at/Event/413

Resolve ‘Device or resource busy’ problems

Upgrading opatch utility consists of two steps

  1. Remove the old copy of opatch by deleting $OH/OPatch directory
  2. Unzip the replacement file into your Oracle home directory

But when you try to remove the contents of OPatch directory you get slammed with errors like this:

rm: cannot remove `jlib/.nfs0000000005213282002649ad’: Device or resource busy
rm: cannot remove `jlib/.nfs000000000523b2e4002649ae’: Device or resource busy


rm: cannot remove `ocm/lib/.nfs0000000005226a87002649b3′: Device or resource busy
rm: cannot remove (more...)

How to update a custom public theme in Oracle APEX

In the last post I showed how you can upload a custom theme to the instance repository so that all your developers can choose that theme within the create application wizard. And more importantly, subscribe that theme from the theme repository.

Now the next question is how to update that public theme so that all applications can inherit the changes.

My first attempt was to simply go to Instance Administration – Manage Instance – Public (more...)

DB2 fully supported on Delphix

I’ve received a number of inquiries lately about the support of DB2 on Delphix and yes, Delphix 5.0 now supports full automation of virtual data for DB2. With the addition of DB2, Delphix now supports full automation of virtual data on all three of the major enterprise databases

  • Oracle
  • SQL Server
  • DB2

as well as Sybase, MySQL and Postgres.

For more information on DB2 in Delphix 5.0 see

Creating a custom public workspace theme

The Universal Theme introduced with APEX 5 is immensly good looking and comes with a powerful Theme Roller to customize it.

With that new theme most, if not all, older themes are obsolete.

That leaves us just with a few corporate designs which can’t (or don’t want to) be replaced by the UT.

Now ideally you want your developers to use that custom theme in all applications and also subscribe to that.
Historically I recommended (more...)

Math Resources

I feel like I have not been posting very much on this blog lately. I have been focused on things outside of Oracle performance so I haven’t had a lot of new scripts to post.  I have been quietly updating my Python source code on GitHub so check that out. I have spent a lot of time educating myself in various ways including through the leadership and communication training program that comes from Toastmasters. My new (more...)

Overcoming Your Oracle Data Insecurity Webinar

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Overcoming Your Oracle Data Insecurity

Webinar – Wednesday, March 30 – 10am PT

In 2016, the risks and reasons why companies should secure their sensitive data are well known (Sony, Target, and Anthem just to name a few examples). Yet, most companies have pitiful or limited data security in their Oracle databases.

Join Pete Finnigan, Oracle security specialist, and discover:

  • The challenges with securing Oracle databases
  • Why and how securing test and development systems are (more...)

AuraPlayer takes Barcelona by Storm at the Mobile World Congress

AuraPlayer was thrilled to attend Mobile World Congress (MWC) in Barcelona. It was our first time attending this epic conference, and we can assure you it lived up to all the hype.

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Suhas Uliyar, Oracle’s VP Mobile Strategy, visits the AuraPlayer Booth

The conference emphasized the mobile revolution occurring throughout all industries and how organizations need to mobilize their business practices or they’ll be left behind. This further reinforces what Grant Ronald always says, “If (more...)

Cedar’s Oracle Cloud Day 2016 – Recap

Cedar held its annual Oracle Day in Oracle’s City office last Thursday – it was actually our 6th year of running the event. The attendance was great – just short of 100 – and with 3 streams of content there was plenty to choose from. If you weren’t there, here’s the highlights of the sessions that I attended:

After the opening keynote from Dan Woolstone, Oracle’s James King and myself spoke to a full room (more...)

PL/SQL Functions in the WITH Clause and Read (In)Consistency

A question was raised in Martin Widlake’s session this morning in OUG Ireland 2016. The (excellent) session was about the performance of calling PL/SQL functions from SQL, and Martin scared the audience (or at least tried to scare…) with the fact that read consistency is not kept (with respect to the base SQL statement) when the PL/SQL functions are called from that SQL statement.
The question that was raised was whether this is also (more...)

Fibre Channel vs NFS

NFS is the future, has larger bandwidth than FC, market is growing faster than FC, cheaper, easier, more flexible, cloud ready and improving faster than FC.

Screen Shot 2016-03-03 at 8.56.29 PM

 

photo by Paul Oka

Fibre Channel

  • Legacy : FC is becoming legacy like Cobal and the Mainframe. Not going way, but not what you want to invest in.
  • Throughput : FC throughput has fallen behind NFS and is the gap is only widening.
  • Price : FC is much (more...)