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August 2012

Future Appearances 2012

Here’s the list of public events where I’ll be speaking this year:

Enkitec’s Extreme Exadata Expo in Dallas, TX (13-14. August 2012):

Additionally I’m going to be around to participate at Q&A sessions, panels, random Exadata hacking and just for fun! :)

 

UKOUG Conference in Birmingham, UK  (3-5. December 2012):

I will deliver 2 Exadata speeches (one of them a 2-hour masterclass) and the “part 2″ of my Troubleshooting Most Complex Performance Issues war stories…

Off Topic Rant – Olympics Athletics Annoyance

I’m very much enjoying the current Olympics, the achievements and drama by so many competitors from all over the world in different events,  and the coverage provided by the BBC  - when they can keep narrative and vision together and they are not asking tired competitors who have just done their all daft questions like “how do you feel now” {I’d love some of them to reply ”Knackered, just sod off OK!”}

However, a concern I have had for weeks seems to be panning out. For athletics I think we will see running. And more running. With running thrown in. Running, running, running. with a light scattering of everything else if there is UK interest. What vexes me is that most of this “running” is not even actual running!

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:

http://www.nocoug.org/Journal/NoCOUG_Journal_201208.pdf

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:

The limitations of CURSOR_SHARING = FORCE and FORCE_MATCHING_SIGNATURE for SQL plan stability

It’s a well known fact that the cursor_sharing parameter can be set to FORCE for making Oracle replace any literals with system-generated bind variable placeholders and then calculating the SQL hash value for looking up an existing cursor in library cache. This should reduce the amount of hard parsing and shared pool garbage.

Also, the same mechanism (of replacing literal values with bind variable placeholders before calculating the SQL hash value for library cache lookup) can be used for enforcing a SQL profile for SQL statements which differ by literal values in them. You just accept a SQL profile using DBMS_SQLTUNE.ACCEPT_PROFILE( …, FORCE_MATCH=>TRUE).

However this “force matching” has one limitation which can make it almost useless for achieving plan stability in databases where the applications use dynamically generated SQL.

The limitations of CURSOR_SHARING = FORCE and FORCE_MATCHING_SIGNATURE for SQL plan stability

It’s a well known fact that the cursor_sharing parameter can be set to FORCE for making Oracle replace any literals with system-generated bind variable placeholders and then calculating the SQL hash value for looking up an existing cursor in library cache. This should reduce the amount of hard parsing and shared pool garbage.
Also, the same mechanism (of replacing literal values with bind variable placeholders before calculating the SQL hash value for library cache lookup) can be used for enforcing a SQL profile for SQL statements which differ by literal values in them.

The limitations of CURSOR_SHARING = FORCE and FORCE_MATCHING_SIGNATURE for SQL plan stability

It’s a well known fact that the cursor_sharing parameter can be set to FORCE for making Oracle replace any literals with system-generated bind variable placeholders and then calculating the SQL hash value for looking up an existing cursor in library cache. This should reduce the amount of hard parsing and shared pool garbage.
Also, the same mechanism (of replacing literal values with bind variable placeholders before calculating the SQL hash value for library cache lookup) can be used for enforcing a SQL profile for SQL statements which differ by literal values in them.

Lights-out management console on Supermicro boards

So this is slightly off topic, as it doesn’t deal with anything directly related to Oracle, it’s more a reference to those who are using Supermicro boards like I do. The nice thing about professional hardware is that you do not need a keyboard or mouse, or even a monitor. The board I have comes with an IPMI interface, and has a KVM over IP ability. The interface can be accessed from a dedicated software or a web browser.

IPMIView

The suitable application to access your KVM is called IPMIView, and it’s available for MacOS, Linux and Windows.

Since I didn’t want to install a lot of application on my laptop I opted to install IPMIView for Linux on my Ubuntu 12.04 LTS desktop running within a virtual machine. However I couldn’t get it to install at all until I found a great source how to do so. Here are the steps: