Oracle Parameter Files

This isn't going to be news to any Oracle DBAs reading this. So if you are one, can I suggest you move along quickly to the next item in your feed reader.

Anyone left is hopefully curious like I was to figure out the difference between 'traditional' oracle initialisation files (init.ora) and the new fangled server parameter files (sp files). Well wonder no further fair reader for I can explain all.

Prior to Oracle 9.2 (a long time ago in Oracle database years) it was only possible to permanently effect the configuration parameters of your database by changing the init.ora file and restarting your database instance. You could make changes whilst the database was running by using the 'ALTER SYSTEM SET' command but these would be lost the next time your database was restarted because the startup process would use the values in your init.ora file. This meant that any instance tuning would require some informed 'twiddling' by the DBA to settle on a suitable value for an instance parameter and that would then be followed by a restart, causing anyone using the database to be mightily inconvenienced.

With the introduction of server parameter files in 9.2 and above changes made interactively (using 'ALTER SYSTEM SET') are automatically persisted. This is because whenever a change is made this way it is automagically written to your spfile.

This article has a much more comprehensive description of the differences between the two different types of files. One of the useful things it mentions is the resolution order the database server uses to select an initialisation file on startup. This is;

  • spfile<SID>.ora
  • spfile.ora
  • init<SID>.ora

Tick another thing off the list of 'stuff that has been bothering me and I need to figure out'.

OSDC 2008

I'm currently in the foyer of the Sydney Masonic Centre setting up the registration desk for the Open Source Developer's Conference 2008. It may be late notice but if you want to see keynotes by Larry Wall, Chris DiBona, Anthony Baxter and Pia Waugh, not to mention interesting talks by another sixty or so speakers, you can still register up to the official conference opening tomorrow morning. More details can be found on the conference web site. Come and say hello if you make it.

OSDC 2008 Early Bird Registration

Early bird registration for The Open Source Developers' Conference 2008 is now open. OSDC 2008 is a conference run by open source developers, for developers and business people. It covers numerous programming languages across a rangeof operating systems, and related topics such as business processes, licensing, and strategy. Talks vary from introductory pieces through to the deeply technical. This year we have an exciting selection of presenters and keynote speakers including:

  • Larry Wall, the creator of Perl
  • Chris DiBona, Open Source Programs Manager for Google
  • Andrew Tridgell, Founder, Samba Team
  • Anthony Baxter, Python Evangelist
  • Pia Waugh, Consultant, Waugh Partners
Check out the draft program: Please visit to register. Early bird registration closes on the 27th October, 2008. For more information about this event, please visit:

Photo Meme

Look, it's me Instructions: Take a picture of yourself right now. Don't change your clothes, don't fix your hair - just take a picture. Post that picture with NO editing. Post these instructions with the picture. Hat tip - Steve Holden and Simon Brunning

Vimoutliner Plugins

I'm a big fan of Vimoutliner and use it for a variety of tasks. I recently managed to break my installation and thought I would document it here for future reference. Vimoutliner comes with a couple of plugins to support checkboxes next to items (for easy to do lists) and a technique called 'hoisting'. Somehow in one of my frequent updates to my configuration I had lost support for both of these features. It turns out that there is a small difference between the default configuration for Vimoutliner and the way I set up my Vim environment. By convention extension scripts for Vim are stored in a 'plugin' directory under your Vim home (which is ~/.vim by default) and that is where, amongst others, I had place vo_checkbox.vim and vo_hoist.vim. But for reasons known only to itself I have just discovered that Vimoutliner looks for extension scripts in a directory called 'plugins' (notice the plural). So a quick directory add and a couple of svn move's later and I was back in business.

Gerald release 0.2.3

I have packaged and released version 0.2.3 of gerald. This is mainly a tidy up and bug fix release, with numerous additional unit tests. You can find all of the details in the CHANGELOG.txt file that comes with the source distribution (or view it here) but in a nutshell the changes from the last release are;

  • Numerous renames to more fully comply with PEP-8
  • Added numerous tests, full details in the CHANGELOG.txt file
  • Added an 'enabled' flag to table constraints (except in the MySQL module, because that database doesn't support them)
  • Added support for column defaults in Oracle
  • Added a 'table_name' attribute to the schema.Trigger class
  • Removed main and usage functions from each module that shouldn't be imported
Please download, install and enjoy. Bug reports or tumultuous praise to the usual address please.

In Praise of the Genius Bar

This won't be news to those of you in more enlightened locations but I had occasion to contrast the service from the shiny new Sydney Apple store genius bar with my previous Apple repair experiences today and walked away a very happy customer. My Macbook had not been well since last week. Basically the fan was running constantly which apart from the annoying noise meant that the battery drained in about 30 minutes. Having had my last machine in and out of third party Apple certified repair shops for most of it's short and inglorious life I was prepared for the worst. I migrated all of my files and data onto a borrowed work laptop and headed to George Street resigned to losing my machine for a couple of weeks. I walked out half an hour later with a fully working machine. Admittedly the fault was minor and easily fixed but with my last machine each of the repair centres I used had a mandatory (usually two week) period where they kept the machine before looking at it. My experience in George street was about fifteen minutes. All hail the shiny new store. Now to see if they can fix the internal microphone.

Shiny New Engine (v2.6)

I've just upgraded to WordPress 2.6. As I have claims to be a technologist I install and upgrade my blog software using Subversion. An upgrade simply requires issuing an 'svn switch' command and then running the WordPress database upgrade via the page that presents. Usually this works like a charm. Today I had issues. I've logged a support ticket but thought I should mention it here in case anyone else sees the same issue. When I tried to log in after the database upgrade the login page just kept re-directing back to itself. The main page of this blog was showing, but with an error message stating (in part) - "error in akismet.php on line 487". After a little checking around I discovered that Akismet (the WordPress spam fighting plugin) needed to be upgraded at the same time as the core WordPress code and hadn't. The old version (2.1.4) is not compatible with the latest WordPress release and needed to be upgraded (to 2.1.6). A simple workaround was to download and install the latest version of Akismet by hand so it wasn't a huge problem, but it would have been nice if the WordPress Subversion repository had been updated to reflect the change. Update: OK, it's probably me. A fresh checkout of WordPress (release 2.6 or 2.5) comes complete with the correct version of the Akismet plug in. It must have a problem with my 'svn switch' that I didn't catch.


I just read, courtesy of Simon, a great article at the Guardian covering a presentation that Adrian Holovaty gave there last week. Strangely enough I was talking about this with a colleague this very afternoon. My thesis was that data is generated by applications but should be considered independent of them. Treat your data carefully and you have a treasure trove of information that defines your organisation. Take an application centric view of the world and you end up with a load of blobs that are only meaningful in the context of your application code. If you can ever find a way to free your information you can find so many different ways of viewing, interpreting and analysing it. In essence this is the excitement that surrounds mashups and the value that shown in sites like Chicago Crime and My Society. Expose the data and then marvel at what happens. As I said in a (remarkably brief) presentation that I gave tonight - I'm Andy and I'm a data manager. If I can ever find a way of making a living taking data, turning it into information and making it available in new and interesting ways I guarantee that I will quit my day job in a heartbeat.

OSDC 2008 Call For Papers

In case you haven't seen this elsewhere; Call for Papers Open Source Developers' Conference 2008 2nd - 5th December 2008, Sydney, Australia The Open Source Developers' Conference 2008 is a conference run by open source developers, for developers and business people. It covers numerous programming languages across a range of operating systems, and related topics such as business processes, licensing, and strategy. Talks vary from introductory pieces through to the deeply technical. It is a great opportunity to meet, share, and learn with like-minded individuals. This year, the conference will be held in Sydney, Australia during the first week of December (2nd - 5th). If you are an Open Source maintainer, developer or user, the organising committee would encourage you to submit a talk proposal on open source tools, solutions, languages or technologies you are working with. For more details and to submit your proposal(s), goto: If you have any questions or require assistance with your submission, please don't hesitate to ask! We recognise the importance of Open Source in providing a medium for collaboration between individuals, researchers, business and government. In recognition of this and ensure a high standard of presentations, we intend to peer-review all submitted papers. OSDC 2008 Sydney (Australia) - Key Program Dates: 30 Jun - Initial proposals (short abstract) due 21 Jul - Proposal acceptance 15 Sep - Accepted paper submissions 13 Oct - Reviews completed 27 Oct - Final paper submission cutoff For all information, contacts and updates, see the OSDC conference web site at Also if you are interested in sponsoring, please see: