Linux posts are by far the most popular. Perhaps this is simply due to the large quantity of Linux related posts I tend to make on this site, although it could be due to the tutorial nature of many of these articles.

Here are the Linux articles which are really ranking highly:

• How to do connection tunnelling via SSH – A reasonably quick and simple tutorial I wrote that briefly explains what SSH tunnelling is and how to make use of it.
• Ubuntu’s Indicator Applet – A now relatively old post which I wrote regarding the indicator applet that came as part of Ubuntu 10.04, and aiding in notifying the user of new email or instant messages and allowed easy response and broadcasting of messages via e-mail, instant messaging or social networks.
• Getting Spotify working in Ubuntu – This post focuses on getting the Windows version of Spotify (a popular streaming music client) working in Ubuntu Linux. This is somewhat irrelevant now however, as Spotify have released a native ‘Linux preview’ version, which tends to work a lot better… ignoring the fact they never made its volume control functional.
• Avatar server farm – Avatar, the film, which I’m sure most readers have seen was rendered with a massive Linux server farm. The server farm’s main rendering machines all ran a version of the Ubuntu. As Ubuntu is my currently preferred distribution of Linux, I figured I would write an article relating to it.

Regarding Internet Explorer, I wrote about an unexpected security feature in Internet Explorer web browser which replaces locally submitted file paths with the unhelpful ‘C:\\fakepath\\’ string. The ‘motivation’ within this post’s title refers to a motivation in the workplace video I posted quite a while ago.

• Internet Explorer’s ‘C:\fakepath\’ security feature – This security feature can easily be worked around for trusted sites via IE’s Internet Options window.
• Motivation within the workplace – An interesting and insightful explanatory video.

I found this image whilst browsing Reddit, which I’ve come to do quite frequently. Although I can not vouch for its statistical accuracy, the likely truths behind it are quite fascinating.

This behaviour is apparently not too anomalous and has been replicated in many locations and by many different professionals in fields such as economics, psychology and sociology. For simple tasks, standard monetary motivators work, but for anything more complex additional monetary motivations do not work as usual. The video suggests one of the ways around this is to pay workers sufficient money such that monetary motivation is not an issue and not relevant.

Once this has been achieved, behavioural science shows that there are three additional factors that improve employee motivations.

1. Autonomy – The ability to direct the course of one’s own life – the work that is performed.
2. Self Challenge & Mastery – The overarching desire for people to improve themselves, gain experience and get better at what they enjoy.
3. Purpose – The reasons you do what you do. Doing tasks merely for money and profit is not too motivating, but doing tasks to make someone’s life better, to make the world better, to have a well defined purpose to your work and to make money – now that is motivating.

Click the image to view it enlarged, on its own.

The BBC who initially reported this proof-of-concept ‘infection’ stated that Dr Gasson admitted that the test is only proof of concept but believe that there are significantly implications for advanced medical devices. In my opinion, such systems should be incapable of malware infection as a heavily important part of their design. Such real-time systems should not have the necessary capacity to carry and distribute, both in terms of storage space and system capability.

If you are running an (operating) system capable of malware reception* on mission critical systems (and thus required anti-malware measures), such as those used in nuclear power plants or reservoirs to regulate containment, there there is a fundamental problem with this design. This is akin to a school teacher wearing a condom during classes – while this technically provides additional safety, there is obviously something fundamentally wrong with this principle at a more basic level.

* I’m aware there is no system that is 100% secure from malware, but levels of security exist. For example, the mission critical systems discussed here do not require a full Microsoft Windows operating system, nor a full consumer operating system of any kind in fact. Such devices should be self-contained in most cases, with entirely custom code. Lesser mission critical systems may rely on a Linux kernel as the base operating system with the business/operational logic running on bespoke programs running ontop of this base system.

The BBC article and Mark Gasson goes into further details on the  security risks of advanced medical devices which may be subject to malware.

“With the benefits of this type of technology come risks. We may improve ourselves in some way but much like the improvements with other technologies, mobile phones for example, they become vulnerable to risks, such as security problems and computer viruses.”

He also added: “Many people with medical implants also consider them to be integrated into their concept of their body, and so in this context it is appropriate to talk in terms of people themselves being infected by computer viruses.”

However, Dr Gasson predicts that wider use will be made of implanted technology.

“This type of technology has been commercialised in the United States as a type of medical alert bracelet, so that if you’re found unconscious you can be scanned and your medical history brought up.”

We can all hope that security in these heavily critical devices is never designed alongside the principles of many general purpose computers.

Imagine an equivalent of the Storm botnet that, rather than infecting and making zombies of its host computers, infects human medical devices. In fact, that is not even a future I want to consider.

1. Press the menu/applications button (bottom left of the phone).
2. Tap ‘Settings’
3. Tap ‘Application mgr.’ (Application Manager)
4. Tap ‘Installed apps.’ (Installed Applications)
5. You will then be presented with a list of all installed applications. Select the name of the application you wish to remove.
6. Tap ‘Options’ and then ‘Uninstall’.
7. You will be asked for confirmation as to whether or not you are sure you with to remove the application. Tap ‘Yes’ if you are sure.
8. The application will then be removed. This may take a while, depending on how large the application is. Repeat these steps for all the applications you wish to uninstall/remove.

Note that for some applications, the ‘uninstall’ option is not available. As far as I am aware, this means the software is built into the system software and thus can not be uninstalled from the phone in any normal manner, without going to the extreme of flashing the phone with custom firmware.

The latest MySQL documentation (5.5) discretly mentions the fact these constraints are unfortunately not supported.

• The CONSTRAINT_TYPE value can be UNIQUE, PRIMARY KEY, or FOREIGN KEY.
• The UNIQUE and PRIMARY KEY information is about the same as what you get from the Key_name field in the output from SHOW INDEX when the Non_unique field is 0.
• The CONSTRAINT_TYPE column can contain one of these values: UNIQUE, PRIMARY KEY, FOREIGN KEY, CHECK. This is a CHAR (not ENUM) column. The CHECK value is not available until we support CHECK.

Take special note of the final line I’ve emboldened. This is quite a shame that this constraint type is not fully supported yet.

Apologies to readers for the implication that this was functional in my previous post, and thanks to the poster of this comment for noticing the discrepancy.

Check constraints, of course, function fine in many other DBMSs, and to that end, the original post on SQL check constraints is still relevant, but sadly not if you are worked with MySQL.

1. Calculate how much carbon your are using, be it in electricity usage, air flights, driving costs or other.
2. Display the amount of money it would take to offset your measured carbon usage.
3. Donate said amount to Climate Care so they can put the money towards offsetting your carbon emissions elsewhere with one of their projects.

The image below shows the carbon emissions calculator the website uses.

I personally think this website is a fantastic way to deal with carbon emissions, by donating a proportional amount of funds to other projects that attempt to compensate for the emissions that are generated. Here are a few quotes regarding climate change, carbon emission offsetting and global warming from the climate change website.

Why should you take action to avoid catastrophic climate change?

Global warming is happening right now in front of our eyes. Our weather is changing. Every one of the hottest 15 years on record has occurred since 1980. There is now huge consensus among scientists that we face serious climate change – we just don’t know what level of severity it will reach or when.

We probably have about 20-30 years left to sort this problem out and we need to spend our efforts and money on actions that deliver the biggest and fastest CO₂ reductions possible. We all have a part to play and we all need to work together to spread the understanding of this issue and our determination to tackle climate change. Work out your own ‘reduce and offset’ plan today with our useful reduction tips.

What is climate change?

When fossil fuels and wood are burnt they release greenhouse gases that occur naturally in the atmosphere, making the average temperature around 15°C. Without this protective ‘blanket’ our world would be a much colder -18°C

However, the extra greenhouse gases that humankind has emitted have already significantly altered the composition of the atmosphere, adding to the blanket and increasing the average temperature of the Earth. This is causing human-induced climate change. To stop this spiralling out of control, we must radically reduce emissions of greenhouse gases into the atmosphere.

Effects of climate change

The real impact of climate change remains worryingly uncertain, with consequences for all communities, species and environments across the world. Effects include:

• Changing weather bringing drought and flooding, affecting drinking water supplies and agriculture.
• Irreversible loss of many species of plants and animals.
• Rising sea levels, threatening freshwater supplies because of salt water intrusion.
• Melting glaciers, threatening freshwater supplies for millions of people who depend on glacier meltwater for their water supply and irrigation.

We will all experience these effects but an appalling injustice of climate change will be that those people in the developing world, who have contributed little towards the problem, are at greatest risk and will be the hardest hit. They have fewer resources for coping with storms, floods, droughts, disease outbreaks, and disruptions to food and water supplies. This is an issue with the welfare of humans at its heart.

What do you think? How at risk are we? Will you be offsetting carbon emissions at all or do you believe the problem is bigger than this?

Google April Fools’ Day Pranks

Google went a bit heavy on the pranks this year, with each department seeming to produce its own set of pranks.

• Google Animal Translate - Google have supposedly released an ever so sneaky version of Google Translate that can translate animal noises in to English! This is a mobile application, suprisingly for the Android platform and is (not) available in the Android App Store. Take a look at the video below.

• Google renames to Topeka – ‘Early last month the mayor of Topeka, Kansas stunned the world by announcing that his city was changing its name to Google. We’ve been wondering ever since how best to honor that moving gesture. Today we are pleased to announce that as of 1AM (Central Daylight Time) April 1st, Google has officially changed our name to Topeka.’

• Google Annotation Gallery – GAG is an open source libary for Java that allows programmers to easily express their emotions in the code… ‘The Google Annotations Gallery is an exciting new Java open source library that provides a rich set of annotations for developers to express themselves. Do you find the standard Java annotations dry and lackluster? Have you ever resorted to leaving messages to fellow developers with the @Deprecated annotation? Wouldn’t you rather leave a @LOL or @Facepalm instead? If so, then this is the gallery for you.’

ThinkGeek April Fools’ Products

ThinkGeek, a huge online store for geek wear, gadgets and generally geeky products released a few extra special products for April Fools’ day this year. This is very typical of ThinkGeek, but this year’s prank products were quite something.

• Canned Unicorn Meat – Which is… well, exactly what it says on the tin, apparently.
• iCade – An arcade machine shaped holder for the new Apple iPad.
• moodINQ – A programmable electronic Tattoo system
• Tell Me Your Secrets Bear – A cuddly bear which had a microphone and camera allowing parents to spy on their children and their secrets.

Your April Fools’ Pranks?

What was your favourite April Fools’ Prank this year, either your own or a prank you saw online?

In fact, anything the human brain and its subconscious is capable of is quite incredible in my opinion. Given that the brain is effectively a collection of cells and electrical impulses it is quite amazing that said biological computer evolved as it did, to allow humans the feelings of conciousness, emotion, learning and the ability to achieve first hand experience.

Source: XKCD web comic

The subconscious mind is even more perplexing, especially during sleep when many of the social constraints our society has in place are released. At this point the subconscious and imagination of you brains can go wild. Of course, not everyone remembers their dreams, and even fewer release they are dreaming at the time. Even fewer still can actually control their own dreams, a process known as lucid dreaming.

Rather unusually for me, I’ve been remembering quite a few of my own dreams recently, and they’ve ranged from mild and pleasant to truly horrific. In light of this, and to satisfy my ever unsatisfied curiosity and hunt for knowledge, I have done a bit of reading around the subject. It turns out that not only are there many, many very common (almost universal) dreams amongst people, but that there is also quite a firm amount of evidence that the dreams we experience in sleep somehow relate to our concious waking lives.

This seems a bit superstitious, bizarre and almost unbelievable at first thought, but if you think about it cleverly, it does make sense. Our subconscious has the same memories, emotions and thoughts to work with as our concious minds, so logically, the two states may be somewhat related, if only in a metaphorically sense. So, I looked up common dreams that people have based on a lot of different sources.

• Being naked – Apparently this one means you’re exposed in concious life, or you may feel you’re revealed a  bit too much about yourself in real life.
• Falling – Ahh… falling is probably the most frequent of the negative common dreams it seems. According to many sources the falling dreams refer to you feeling insecure in some aspects of your life. It can be related to not feeling like you have a safety net in life to fall back on in a particular situation, which is quite an interested thought, and related (metaphorically) heavily to the dream itself.
• Drowning – People who are particular overworked, stressed and on edge can feel like they are metaphorically ‘drowning’ in an overflow of information, thoughts, emotion and stress. Drowning dreams it seems, tend to come from these particular ‘stress’ related emotions… phew.
• Lost and/or trapped – Like drowning dreams, this can also be stress related, but according to what I’ve read, this can also mean you are significantly confused or can not understand a certain situation, or feel you do not even have the ability to understand or solve it.

These are many of the common negative dreams. There are of course positive opposite dreams to these, which based on other source tend to relate to the opposite equivalent emotions as well.

In fact, there is quite a lot of information about common dreams available.

So, do you think your dreams are at all related to your real life? Have you ever had these so called common dreams in situations which match up with their supposed explanations?

The ‘C:’ device represents the very small, primary internal flash memory present on the phone. The secondary storage device, usually ‘D:’ or ‘E:’ is much larger (in my case 32GB), but unfortunately not everything can be installed to the mass storage. For those applications that truly need to be installed on the primary drive, they can use a great deal of the limited space.

Here are a few tips I discovered on how to help clear out the primary drive’s space. You’ll know if you need to do this if you are receiving constant reminders that your phone is out of space on drive ‘C:’.

1. Any applications previously installed on C: that could be installed on E: should be uninstalled and reinstalled on the larger storage device.
2. Install third party web browser, such as Opera Mobile, to the mass storage and then delete the ‘C:\System\Cache\’ folder belonging to the default Nokia web browser.
3. Change the default ‘Messaging’ storage to mass storage. To do this, open the messaging application and then go to Options > Settings > Other > ‘Memory In Use’.
4. Uninstall any of the uninstallable default applications and widgets that you do not use. I removed the ‘Facebook’ home screen widget and now just use the mobile web version of Facebook.
5. Make sure the Ovi Store is set to install to mass storage by default. To do this open the Ovi Store settings at Options > Account > Settings > Installation Preferences, within the Ovi Store application itself.
6. If you are using Nokia Messaging or Nokia Messaging for Exchange, delete and reconfigure your accounts and this will clear out a significant cache. Alternatively, if you do not mind, remove the Nokia Messaging application entirely and use a web-mail alternative (if possible).

In my case, removing Nokia Messaging was the most helpful. Anyone else had this problem, if so, how did you clear your N97′s main memory?

“Ends up that just blowing up iPhone apps to fill the iPad screen looks and feels weird, even if you use higher-resolution graphics so that nothing looks pixelated. So they were scrapped by you-know-who. Perhaps they’ll appear on the iPad in some re-imagined form this summer with OS 4.0, but when the iPad ships next month, there won’t be versions of these apps”

The iPhone apps, when scaled up to iPad’s larger screen, did not live up to Steve Jobs’ expectation, so due to this, they were scraped from the iPad’s release operating systems. Rumours exist that these apps will be added in a later update to the iPad’s operating system. This is quite important too, as the missing applications are simple and rather fundamental computing programs which I would personal expect to be in any modern general purpose device.

Missing Apps on the iPad

The list of applications scraped from the iPad’s operating system is as follows.

1. Clock – Something as important as the clock application is missing?
2. Calculator – Surely a similar app will be released to compensate the lack of a Calculator app?
3. Weather – No doubt a good third-party whether app will take the place of this if no official weather application is released.
4. Voice Memos – Seems it should still be in there? Why remove it?
5. Stocks – Not fundamental to all users by any means, but should still be a nice default.

Questions for existing iPhone users:

• Why would Apple really want these applications removed other than merely that they look ‘weird’?
• If you had an iPad, would you want these applications to be there as standard? If so, which ones?
• Are these applications (on the iPhone) used regularly and important to you already?

As assumed by many PlayStation 3 users, the issue was not related to the PlayStation Network but was, in fact, an issue with the hardware in the (non-slim) PlayStation 3 models. The on-board clock on the PlayStation 3 assumed the date on the 1st of March was in fact, the non-existant 29th of February. At the same time, the operating system clock believed the date was, as it actually was, the 1st of March.

We can assume Sony believed the best option was to merely await this automatic ‘fix’ that occured at midnight, rather than to develop, test and release an emergency update to all old model PlayStation 3 models. This is most likely due to a strict policy on testing such system updates. This choice to delay may be looked at as a bad action by some people, however imagine the dangerous alternative. If Sony were to have released a rushed update to all old PlayStation 3 models… and it bricked the consoles (i.e. made them inoperable) – imagine the up roar then?

What do you think Sony should have done?

Frankly, I think they should have been more thorough in the initial testing of the PlayStation 3 components, such as, perhaps, the on-board clock…

1. Any PlayStation 3 games with associated trophies can not be played.
2. The PlayStation Network (PSN) can not be connected to (error 8001050F), and thus all PSN related functionality, such as the friends list, messaging and the PlayStation store is non-functional.
3. The date of the system is reset to the 1st of January 2000 (error 8001050F) and can not be reset automatically, but can be changed manually.

Sony has recently clarified some of the issues relating to this problem is the latest updates to the Sony PlayStation blog, as follows. It is very interesting to note that Sony is still claiming this is a PlayStation Network issue in the blog posts titles, when it is actually a fault in the synchronisation of the system clocks.

• PlayStation Network Status Update – Original update stating Sony are aware of the issue and are investigating the related problems.

“We’re aware that many of you are having difficulty connecting to the PlayStation Network this evening. Those of you with “slim” PS3s (the 120/250 GB models) appear to be unaffected.”

• Latest info on PlayStation Network Status – A more detailed and recent update on the problem, indicating the symptoms of the issue. This update also admits to the issue is “caused by a bug in the clock functionality incorporated in the system”.

“We believe we have identified that this problem is being caused by a bug in the clock functionality incorporated in the system.

Errors include:

• The date of the PS3 system may be re-set to Jan 1, 2000.
• When the user tries to sign in to the PlayStation Network, the following
  message appears on the screen; “An error has occurred. You have been
  signed out of PlayStation Network (8001050F)”.
• When the user tries to launch a game, the following error message appears
  on the screen and the trophy data may disappear; “Failed to install
  trophies. Please exit your game.”
• When the user tries to set the time and date of the system via the
  Internet, the following message appears on the screen; “The current date
  and time could not be obtained. (8001050F)”
• Users are not able to play back certain rental video downloaded from the
  PlayStation Store before the expiration date.

We hope to resolve this problem within the next 24 hours. In the meantime, if you have a model other than the new slim PS3, we advise that you do not use your PS3 system, as doing so may result in errors in some functionality, such as recording obtained trophies, and not being able to restore certain data.”

I’ve previously written about the PlayStation 3 March 1st 2010 issue when I was first made aware of it.

I want to play Heavy Rain and get it finished. Anyone else annoyed?

It seems that the PlayStation 3, the original – not the slim version, is programmed with an invalid leap year reference for 2010. Due to the fact the PS3 believes this year is a leap year, February is being considered to be over 28 days long in 2010. The PlayStation 3 does not quite understand this it seems and the problem is causing significant issues for many gamers. This leap year problem is causing games to crash (even single player games), connections to the PlayStation network to fail, Trophy information to become corrupted, dynamic themes to fail and the inability to launch certain games at all. Some users are also reporting a variety of error codes including error 8001050F.

It seems all these problems boil down to an issue within the original PlayStation 3′s firmware which is preventing many date and time related functions to fail. Luckily, the PlayStation 3′s system software update relies only upon an Internet connection and does not rely on a connection to the PlayStation network. Sony are apparently looking into the issues, and gamers are expecting a software patch within 24 hours.

There is a basic FAQ about this issue, as quoted below.

“Here’s what’s going on right now: something with the PS3′s internal clock has borked in some pre-slim models. This is not a PSN issue; it has to do with your PS3′s clock. This clock is NOT related to the OS clock. It seems to be a leap year bug. Setting your clock ahead will do nothing. All PS3s around the world were affected at the exact same time.

Does this affect me?

-If you have a Slim PS3, you’re good to go. Continue playing it as normal.

-If you have a “fat” PS3, you may be affected. Some fat PS3s have worked ok, but it seems a good majority have been bugged.

What does this bug mean?

-If affected, your date and time has been set to a random past date. This prevents you from signing into PSN, playing any PSN games, or using any DLC. Your trophies will also not display correctly or be able to sync.

How do I fix it?

-You can’t. Even if you don’t sign into PSN, it won’t help. This is a hardware issue.

So, what do I do?

-Wait 24 hours. Other products that have had similar bugs have corrected themselves after the “bugged” day. On Monday around 6pm central time, all PS3s will automatically correct themselves…maybe.

-If that doesn’t work, we’ll need a firmware update from Sony, which should be a pretty important priority for them right now.

Did I lose my data/themes/etc?

Your save data/games/dlc/themes are fine. They’ll be fixed when the PS3 is fixed. Trophies are uncertain right now, but they’ll be fine if you’ve synced them before the PS3 was bugged. Unsynced trophies are an unknown right now.

If I have a bugged PS3, can I still use it?

It’s probably not a good idea, as I have no idea what will happen to the trophies you earn during the bugged time. Movies/media will work fine.”

…

“The going theory is that the PS3 is storing some form of date in GMT, then modifying that to get whatever you see in the on-screen clock. That modification process seems to be fine–the system can take 2/28/2010, 9PM GMT, add four hours, and get 3/1/2010, 1AM random time zone.

What’s apparently effed, as speculation goes, is when the internal GMT-tracking rolls over to 3/1. It’s either not rolling, or rolling to 2/29, at which point a system tries to add/subtract from 2/29, which it can’t do because the front-end calendar doesn’t have a 2/29/2010, and shit explodes. Seemed to happen around 4PM PDT, which I think is 12AM GMT, so.

And the PS3 launched in 2006; it’s hit 4 2/28s so far. 2007 and 2009 were odd-numbered years; 2008 was an even, and a leap year. 2010 is the first even non-leap-year the system’s been around for. If some sort of base-level math is choking on itself, it may have ruled out the odd 2007 and 2009 successfully, but is convinced the even 2010 is a leap year (this part I’m less sure of, but is why leap year could theoretically come into play at some point.)”

Neogaf Forums Post

I’m quite highly anticipating the release of Google Chrome OS – Google’s net book and appliance cloud operating system. There are a few main reasons behind this.

Simplicity and Openness

Note that I combine the two here. It is very important that both software user friendliness is combined with the nature of free and open source software to prevent device and software simplification becoming a model for restricted development.

Apple do one of these well – simplicity. Apple products are almost always considered to be highly user-friendly and easy to use for all consumers, taking the iPhone and iPad as the latest examples within the consumer electronics market.

However, Apple has a very closed nature to their software models, especially with the iPhone and iPad, where all application acquisition is restricted to a specific Apple controlled ‘App. Store’ and all application developement is restricted to a Apple controlled SDK (software development kit) which is platforme restricted and incompatible with all platforms other than Apple’s own Mac OS X platform.

Promotion of Open Source Software

Since Google Chrome OS is to based upon a Linux kernel, and use many existing Linux systems, not only will this bring improvements to Linux operating systems as a whole due to Google’s code contributions, but additionally it will bring Linux and, more generally, open source software into the light.

The concepts of Linux and open source software are by no means yet the household names of Microsoft, Windows and Apple. Dependant on how Google Chrome OS is marketed by Google, this release could be a great boom for the promotion of Linux as a whole.

Zero Price Operating System

Since Google intends to release the operating system for free (zero price), it will likely also reduce the apparent worth of paid operating systems, such as the paid offerings by Microsoft (Windows) or Apple (Mac OS X). The increased use of web applications and the Internet to do many daily tasks makes Google Chrome OS perfect for the most common uses of computers today. For these tasks, alternative operating systems hold no significant advantages, whilst the advantages for Microsoft and Apple operating systems now lie specifically in the domain of platform restricted software packages, either in the desktop realm, such as Microsoft Office / Apple iWork or the server realm, such as Microsoft Exchange / Mac OS X server software packages.

Even then, with the growth of multi-platform, online productivity and collaboration tools, such as Google Docs, Google Calendar and Google Mail, these platform restricted ‘offline’ software packages may become redundant as more and more businesses and enterprises rely upon the Internet and cloud based applications and storage.

What do you think? Will Google Chrome OS be a boom for Linux, and will its competitors’ offerings be hurt significantly by its release?

You can create a table with a check constraint in MySQL as follows. The check in this example disallows values of the ‘P_Id’ field from falling outside of the condition ‘P_Id>0′. In other words, the ‘P_Id’ field’s values must almost be greater than zero in order for the data to be accepted into the table by the database management system (DBMS).

CREATE TABLE Persons
(
P_Id int NOT NULL,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Address varchar(255),
City varchar(255),
CHECK (P_Id>0)
)

You are probably wondering how to add a constraint to an existing database table. This is quite easy, and uses an ‘ALTER TABLE’ SQL query. See the following example for how to add a check constraint to one of your existing database tables.

ALTER TABLE Persons
ADD CHECK (P_Id>0)

For more information, there are other highly useful example queries relating to SQL check constraints at the relevant SQL check constraint article on W3schools.

The Weta Digital server farm or ‘rendering wall’, as they call it, has a disk array capable of storing roughly 2 petabytes of data in total. The individual servers are linked by a 10 gigabits per second networking infrastructure, and in total there are 35,000 cores based in over 4000 Hewlett Packard Blade servers. In the case of Avatar, each minute of rendering equates to approximately 17.28GB of data.

The system is entirely water-cooled, as traditional air and fan cooling systems are not sufficient during near deadline times, due to constant high load on the servers.The photograph below shows the enormous water cooling system cooling a portion of the server farm.

The high power server farm used to render many films computer generated imagery (including Avatar), shown with its advanced water cooling system.

According to Paul Gunn, a systems admistrator at Weta Digital, Ubuntu is at the core of almost all their systems. Ubuntu runs on all of their 3D rendering servers, and at least 90% of all their desktop systems. More detailed information about the Ubuntu powered rendering farm that rendered the CGI of Avatar is available from the Information Management and IT World websites.

Douglas Crockford selected the MIT license for his JSMin program to reduce JavaScript code syntax in such a way to make it still functionally identical but smaller in size to enable bandwidth savings when these JavaScript files are downloaded by end-users’ web browsers. Ryan Grove continued to utilise this license for his variation of JSMin called JSMin-PHP, appropriately rewritten in the PHP language. This specific license however, contains a variation from the original MIT open-source license, as it includes the following line of text, originally inserted into the license for assumed comical value.

“The Software shall be used for Good, not Evil.”

Since Google’s code hosting solution, imaginatively called ‘Google Code’ only allows hosting of code licensed under very specific open-source licenses, this single modification acts an additional condition which Google is not willing to accept. This means JSMin-PHP can not be hosted at Google Code simply due to this licensing issue.

The developer of JSMin-PHP, Ryan Groove has the following to say about this, on his blog.

“As Google (and some others) interpret it, this additional requirement constitutes a vague use restriction and thus makes the license non-free. Chris [DiBona] explained that if I were to remove that line from the license and ‘return to a proper open source license that we support,’ then jsmin-php could stay on Google Code. Otherwise, he said, ‘we can’t host you,’

… Of course, I can’t change the license, because it’s not my license. It’s Douglas’s license… All derivative works and copies of jsmin.c either include this license or are in violation of it.”

If you are using Google Code to host your project, be warned, Google are very tight on their licensing restrictions. What do you think? Valid reasoning or over the top enforcement of open-source licensing terms?

Glad I got my new winter coat recently…

To make good television, that’s why.

The t-shirt is a very political piece of apparel and none of the other clothing wears, except perhaps the bra, can lay claim to such a significant role in society. Before the industrial revolution, clothing was just considered one of the three basic needs of man apart from food and housing. And like the other basic needs, clothing was worn to keep man warm. Thus, clothing consisted of hand-stitched materials sans the artistic characteristics that today’s clothing boast of.

The growth of the t-shirt industry started side by side with the industrial revolution as the latter allowed the mass production of t-shirts. The United States and Europe share the history of t-shirt because while the cotton material from which t-shirts were originally made was sourced from the US, it was the Europeans who first manufactured t-shirts as underwear.

However, this does not discount the fact that the t-shirt may have originated from the Egyptian Tunic which was used by Egyptian farmers thousands of years ago. The tunic, which was worn under the Egyptian toga, is either plain or with stripes depending on the status of the wearer in the Roman society.

One significantly humorous timeline in the history of t-shirts was during World War II when the American soldiers, who were sweating it out under their woolen uniforms, noticed how comfortable the European soldiers were in their undershirts made of cotton. The War was ultimately won and lost depending on which side you are on but American won because the soldiers were able to bring back one important clothing item—the t-shirt.

While the working class in America sweated it out under their vests, the European workers worked manually wearing only their t-shirts. But this was changed in the 20th century when t-shirt became a popular clothing wear not only in Europe and American but all over the world.

T-shirts are an important part not only of history but of economics considering the multi-billion industry spawned by the t-shirt business. If you don’t believe this then take note that at least two billion t-shirts are sold all over the world every year. Millions of t-shirts are donated to the Salvation Army annually and these are auctioned off to third world countries.

Through the years, the t-shirt has become an important propaganda and marketing tool not only for politicians but for corporate entities as well. The movie ‘The Wizard of Oz’ which was shown in 1939 got a lot of help from the promotional t-shirts featuring the movie’s characters. Marlon Brando’s fans would never forget the body-fitting t-shirt he wore in the play ‘A Streetcar Named Desire’ in the 1950s. More than $8 million worth of t-shirts helped launch the career of Farrah Fawcett in 1977.

The t-shirt may have been in existence since the ancient Egyptian era but it is ironic that Webster’s Dictionary only listed it as part of the book’s official word in 1920.

T-shirts are part of the American life as much as French fries and burgers. It may be nearing a hundred years old but its popularity is growing and does not show any sign of going down. This is evident with the result of a survey which shows that over 62% of people in the US of all age bracket own at least, not one, but ten t-shirts. Those within the ages of 18 to 24 however claimed they own more than 10 t-shirts.

Today, you can find t-shirts in all colors screaming the headlines of the society. It is popularly used as a tool to promote political statements, corporate promotions and even sports events. Rock bands have made millions from t-shirts printed with their names and images.

Most cloth dyes make use of chemicals that can be poisonous when large amounts are accidentally swallowed. However, most of the cloth dyes commonly use din the households are made of substances that are non poisonous including salts, pigments and mild soaps. However, these cloth dyes can still be dangerous so care should be observed when handling them.

There was a time when textiles and clothing wear were colored using natural dyes which were sourced from plants and animals. However, new advances in science in the 1800s allowed the production of synthetic substitutes for natural dyes. The use of natural dyes is preferred considering that it is not toxic and does not hurt the environment.

Natural Dyes

Natural dyes can be classified depending on their sources. Those that are sourced from plants are called indigo, those from minerals are called ocher while those sourced from animals are called cochineal. Among the fabrics which can be easily colored by simply dipping them into the dye are wool and silk. Cotton however requires a mordant to hasten the chemical reaction so that the dye is easily absorbed by the fabric. Natural dyes for cotton rely on mordants like copper, chromium, iron and metallic aluminum salts to ensure the fastness of its colors when washed and dried in the sun.

Substantive dyes do not require mordants before they can easily be absorbed by fabrics. On the other hand, adjective dyes need mordants to be absorbed by the fabrics. If you are making natural dyes then make sure to use non reactive containers like stainless steel and enamel as oppose to iron or copper pots which can easily react with the dye.

The problem with natural dyes is the lack of consistency in their colors. Each natural dye has a unique color which may be exciting to the paint manufacturers but is frustrating to the pharmacology technicians. To standardize the colors of natural dyes, pharmacology technicians came up with a color index for natural dyes which requires that each dye is named using the pattern natural plus base color plus number.

There are various plants from which natural dyes are sourced including berries, field madder and dandelion root for the colors pink and red, walnut husks, and onion skins and lichens for the color brown and its various shades, St. John’s Wort and Goldenrod are the sources for the color yellow, cornflour and wild pansy are the sources for the color blue while sorrel and foxglove are the sources for the color green.

To make natural cloth dye you just have to boil the plants until the color comes out. Then soak the fabric in the boiling water to get the desired color. Using a mordant will permanently set the dye into the fabric.

Cochineal dye is sourced from the cochineal bug which thrived in the cactus plants. The Indians discovered the coloring property of the bugs. The bugs, which are dried out under the sun, produce a rich red powder when grounded. This produced the red coloring when mixed with water.

Synthetic Dyes

Today, most textile manufactures use synthetic dyes to color their products not only because of the ease with which it can be produced but also the accuracy of its colors. Synthetic dyes also have good color fastness which is not usually found in natural dyes.

Synthetic dyes were discovered in the latter part of the 19th century. Aniline dyes or synthetic dyes, which were produced from coal tar derivatives, produced more vibrant colors that did not wash off from the fabrics compared to the natural dyes.

The first aniline dye named ‘mauve’ was discovered by William Perkin in 1856 when he was an 18-year old student studying chemistry. This revolutionized the dyeing industry which relied on inconsistent and unreliable natural dyes.

This apparel is perhaps one of the oldest clothing designs that are still widely used today. T-shirts were already being used by the ancient Egyptians. However, the t-shirt was made more popular during World War II when the American soldiers noticed how they were sweating underneath their uniforms made of wool while the European soldiers were very comfortable under their undershirts made of cotton.

The English were the first to develop and use cotton t-shirt as under-vest in the 1880s. The United States Navy, which require the servicemen to wear light undershirts called crew necks in 1913, is also credited with the development of the t-shirt.

While the t-shirt design is basic for all manufacturers except for innovations like pockets and long sleeves, the material out of which the t-shirt is made is crucial to the shape and comfort of the t-shirt. A lot of people have found themselves excited about their new t-shirts only to find out that it had shrunk or faded after being washed and dried.

T-shirts can be made of different materials but they are basically categorized into natural cloths and artificial clothes. Under the said categories are polyester fibers, cotton, combination of cotton and polyester fiber, cotton spandex and jersey.

Those who go for comfort opt for t-shirts made of 100% cotton while those who want a durable t-shirt that will not fade or shrink opt for t-shirts made of a combination of cotton and polyester. There are a lot of choices when it comes to the material from which t-shirts are made of. Even the cotton from which t-shirts are made can refer to artificial cotton or organically grown cotton. Those who are conscious about the environment opt for t-shirts made of cotton that are organically grown.

Organic cotton is the preferred t-shirt material by those who do not want the chemically-laden conventional cotton in the t-shirt they are wearing. Conventional cotton is grown using toxic substances so in some ways it can have an impact on the environment and even in how your t-shirt feels when worn. Cotton that is grown organically does not cause allergy because they do not have pesticides and chemical bleaches.

Athletes prefer to use t-shirts that are made of stretchable materials like jersey since they are not only inexpensive but are comfortable and versatile. Jersey t-shirts are easy to use especially for heat design transfers and silk screen printing. For a snugger fit, manufacturers use rib knit fabrics for high quality t-shirts.

T-shirts made of white clothing materials are often preferred by people because they do not fade. However, if you want colored t-shirts that will not disappoint your after washing, make sure you get quality colored t-shirts that would not fade and have minimal shrinkage.

All shirts shrink to a certain level after washing but you can look for t-shirts that have minimal shrinkage levels like t-shirts made of a combination of cotton and polyester. T-shirts made of 100% cotton will tend to shrink more than those made of polyester. You can also check the washing instructions at the tag or label of the t-shirt. But no matter what material your t-shirt is made of make sure you turn the t-shirt inside out when you wash and dry them to minimize fading.

The t-shirt industry is one of the businesses that are heavily reliant on the clothing industry for their raw material. However, most people do not really care what materials their t-shirts are made of provided they have eye-catching designs and colors.

This versatile apparel has come a long way from its beginnings in 1920. The t-shirt has evolved from a simple short-sleeved crew neck design to the now in-demand t-shirts with V-necklines, long sleeves, and with or without caps or hoods.

The first step in creating t-shirts involves the selection of the appropriate clothing material for the specific type of shirt you have in mind. T-shirt design is basically the same for all manufacturers except for a few variations in the sleeves and pockets.

T-shirts are made of different materials including polyester, cotton or a combination of these two materials. Those made of cotton are however much-preferred by people living in the tropical areas as they are much cooler. Lately though, t-shirts made of knit fabrics, rib knits, jerseys and interlock rib knits have become popular. Jersey t-shirts are much cheaper and are thus more popular among the masses. Consumers who are conscious about the environmental effects of the products they wear however opt for t-shirts made of cotton that are grown organically.

They look so simple but have you thought about the hours of work and creativeness exerted in the process of creating the t-shirt you are wearing? Thanks to the industrial revolution t-shirts are fairly easy to make and the process is highly automated.

Even small establishments that manufacture t-shirts already rely on machines that have been specially designed to perform the different steps in creating t-shirts from the cutting stage, assembling and then sewing. T-shirts have very simple patterns and this consists of the separate sections for the front and back parts plus the sleeves and pockets when it applies.

T-shirts are like blank canvasses that are manufactured to give artists a chance to dabble with paint. Mass-produced t-shirts however have identical designs and patterns.

The final stage in making t-shirt is the attachment of the label at the neckline

Later today (1st October 2009), the Spotify client will be activated with a new feature – offline mode and the ability to syncronise playlists to your computer’s hard drive. The mobile Spotify applications, for Google Android phones and the iPhone, had this feature upon release and it is now being integrated into their primary product, the desktop Spotify application.

Update: Spotify have sent offline mode live and made an annoucement about offline mode on their blog.

The image above displays how Spotify will show tracks which are currently downloading to your computer’s hard drive and the playlist icon indicating whether or not a playlist is set to the ‘Available Offline’ status. To set a playlist to be available offline will be a simple matter of right-clicking the desired playlist and clicking ‘Make available offline’ from the right-click menu. The chosen playlists and all their tracks will then be downloaded to your computer’s hard drive (encrypted of course) and be available to play if your Internet connection goes down temporarily or even if you have no connection at all. I would imagine, although this has not be confirmed, that users will be required to login (online) to Spotify at least once a month so the client knows the Premium subscription is still active.

Spotify themselves announced the following regarding Offline mode.

“We’re proud to announce that later today we will be extending the popular ‘Offline mode’ that is available on Spotify Mobile and bringing it to the desktop version of Spotify.”

“Beginning later today, Spotify Premium subscribers will be able to select their playlists and set them to be ‘Available offline’. Those playlists will then be synced to the computer so you can listen to your favorite tunes even if your internet connection goes down or if you’re at summer house with no connection at all.”

It appears this idea was originally submitted by a Spotify customer on Spotify’s idea pages, as ‘Offline Spotify’.

“It would have been great if it could be turned on “Offline mode”. So the music that we listen to most, could be listen to, even in offline mode.”

More information about Spotify’s new offline mode is available from TechRadar, the Telegraph and Times Online.

• systeminfo | find “Up Time”
• net statistics server (Note that this command displays actually shows the last boot time from which the uptime can be calculated)
• Uptime (This command is not included in the operating system, but is an uptime utility provided by Microsoft)

Also, it is worth noting that Windows Server 2003 systems and above record their uptime in the System event log at midnight every night, as Event ID 6013. See the screenshot below from a Windows Server 2003 uptime event.

In Mac OS X, Linux, Unix and other Unix-like operating systems, simply enter the following command into any terminal and the current system load values and uptime will be displayed.

• uptime

In OpenVMS systems, the following command provides the system uptime.

• show system /noprocess

Hope this helps you find the uptime of your system regardless of the running operating system, be it Windows, Linux, Mac OS X, Unix or any other system.

If you know uptime commands specific to any other operating systems not listed, please use the comments system and I will update this article accordingly. Of course, feel free to post your uptime(s) as well – a good bit of competition is always healthy!

More information is available about Spotify at the following links:

• Official Spotify website
• Spotify wikipedia article

The following Spotify guide is available on this website.

• How to get Spotify links to work in Linux

If you are looking for the country Jordan, then boy are you lost.

However, if you are looking for the Canadian lacroose player, then you’ve come to the right pl… wait, no, you haven’t.

My name is Jordan Hall and I am the author, programmer and if you will take a trip to the early ninties with me, ‘webmaster’ of this website. For more detailed information about myself, please see my biography.