Relaxing On the Couch

By David Hollingworth, 26/09/2009 9:01 pm

 

For the last few weeks I’ve been spending some time relaxing on the couch. Well that’s actually working with the Apache Couch DB database.

Most of my career in IT has been spent working with relational databases, principally Oracle and Informix and more recently MySQL. Couch DB represents a bit of a departure from this area in that Couch DB is a document database. Instead of being stored in normalised tables or rows and columns all related data in Couch DB is stored together in JSON format documents. Instead of writing SQL queries to access data you use view constructs written in JavaScript and stored is special design documents. Creating a view creates a btree index in the database and allows very fast access to the relevant documents.

Couch DB utilizes a RESTful interface and so is unsuitable for things like banking applications that need transaction concurrency. However it’s great for things like blogs and other text based applications. Instead of row level locking present in relational databases Couch DB employs Multi-Version Concurrency Control (MVCC). What this means in practise is that users each get a consistent snapshot of a document without having to wait for other users to release locks on a document.

The database itself is still fairly young and the API is open to change as it matures. There’s a variety of language libraries also available; but some of these are also a bit immature and some lack some basic functionality or are difficult to implement. To avoid reliance on third parties and to be able to react quickly to changes in the database API I’ve been using the Couch DB JavaScript class library and have found this perfectly adequate for the prototype and proof of concept work I’ve been doing to date.

So far I haven’t written anything earth shattering to be worth sharing any code. So instead I thought I’d just list some of the excellent resources and tutorials I’ve referenced over the last couple of weeks:

There’s probably been others, I’ll add them in as I come across them; but for now… relax!

 

 

Review: Personal Brain from TheBrain.com

5/5

In the past I’ve reviewed Mind Manager – an excellent piece of software for producing mind maps – a tool I that forms part of my daily work flow for information gathering and organizing. However I’ve recently discovered something called "Personal Brain" from TheBrain.com that really takes mind mapping to a whole new level.

Screenshot of a Personal Brain in action

The problem I’ve always had with a mind map is that it’s essentially only two dimensional. You start at the ‘root’ node and work outwards in a hierarchy. You can create any number of hierarchy from the centre; but problems start to occur when you want to link from one hierarchy to another. Things start to get complicated and a complex map can be difficult to navigate and locate the information you need.

The Personal Brain takes a more 3 dimensional approach to organizing data. You can link nodes to multiple parents and to multiple children allowing for a network of cross links between information nodes. In addition to linking parents and children you can ‘jump’ create links to other topics. These are links to topics that are related but don’t form part of the current parent / child hierarchy. I guess an example might help:

Parent, child and a jump topic 

Here we see my TulligWeather server is a child of Servers; but because it is weather related there’s a jump link to Met Eireann. In practice this makes it simple to create complex relationships between topics and yet make them easy to navigate.

As well as creating the topics you can add notes and attachments to them as well as giving them a type and adding tags. The latter allows you to view the tags as a virtual topic showing you all the topics with that tag. Here’s a shot showing a PHP tag and it’s associated topics.

The PHP tag used as a virtual topic

Full search capabilities and and trail of recently accessed items make locating items in unrelated parts of a map easy. Additionally you can pin major topics to the top of the work area to help facilitate moving around different parts of your ‘brain’.

Personal Brain is available on Windows, Mac and Linux. That last one is a big bonus for me as I’m using Linux most of the time at present. The Linux version does have some features that don’t work like dragging files onto a topic to create an attachment; but for most things there’s a valid work around and I haven’t found anything that I really couldn’t do. There’s 3 versions available; free, Core and Pro. The free version has quite a few restrictions; but should still be usable. The Pro version includes integration with Microsoft Office, integrated calendar and a number of other useful features; but is very expensive at $249. I’ve been trialing the Pro version which is die to expire in a few days. Due to current financial constraints I’ll be switching to the free version at that time and I’ll let you know how that works out.

 

Rated 5/5 on Sep 26 2009
Vote on David Hollingworth’s reviews at LouderVoice

Onwards

 

After the wind up of Computer Troubleshooters – West Cork I’ve been looking around for some full time employment again. However there seems to be very little in the way of IT development work in Cork unless you have either Java or C# or .Net skills and unfortunately these aren’t part of my current portfolio.

So on Monday I’m starting a 3 month stint working for Amazon customer services up at the Cork airport business park. This may seem a bit of a departure from my usual role in IT; but it’s not something I’m completely unfamiliar with. I worked for the customer services division of Bull Information Systems in the UK between 1989 and 1999 and the customer service ethic is something I’ve tried to embody in the work I’ve done since then. My ex-customers might comment on how effective that was :)

Either way Monday marks a new start. I hoping it’ll open some new doors and I’m sure it’ll present plenty of opportunities along the way.

Onward and upward…

The Demise Of The Photo Blog

By David Hollingworth, 19/09/2009 1:07 pm

 

I’ve finally decided to tear down my photo blog. Not from a lack of interest in photography; but because the comments section was a complete spam magnet. I was getting hundreds of spam comments every day and while Akismet was picking up most of these it wasn’t catching all of them, which meant more administration overhead than I was prepared to put up with.

So from now on anything I consider to be worth posting will have to go into a post  here. Or I might even open a Flickr account…

Reviewed – Dirt2 on the Wii

By David Hollingworth, 15/09/2009 4:22 pm
2/5

There’s nothing makes me reach for the blog faster than the feeling I’ve been ripped off and this is certainly the case with the video game Dirt2 on the Wii.

I’m a long term fan of motor sport video games ever since I owned Gran Tourismo on the PS2. I rue the day I gave that to my daughter in favour of a Wii. So I was delighted to see the announcement of Dirt2 available on the Wii platform. However I was hugely disappointed when I fired up my console and started the game.

Right from the opening sequence the game displays the poor quality graphics that are present throughout, though thankfully not quite as bad as the opening sequence. The game is divided into the usual arcade mode and championship mode in which you can unlock new vehicles and ‘body kits’, the latter being little more than alternative skins for the cars. There are very few cars available even once you’ve unlocked them and no upgrade or maintenance facilities.

The racing itself is reasonable; but here again the poor quality graphics really show the game up. Surrounding textures, trees for example, are little more than green blobby things and there’s little in the way of distant textures. The vehicles don’t show any highlights and even though we’re racing on dirt there’s no clouds of dust to obscure the view. The driving experience is OK; but there’s very little available in the way of drift. Touch the brakes to try and fish tail the back end in a corner and your more likely just to come to a stop than slide round the bend. The AI cars frequently don’t put up much of a fight and will often brake hard on a straight stretch for no apparent reason. They’ll usually do this at the same point on each lap so you can predict where it’ll be easy to pass them. Altogether unsatisfying.

You can play the game using a variety of different controller combinations and I started using the Wii remote and nunchuck, which was OK. However I then switched to the Wii steering wheel. Turning the wheel is supposed to steer the car, only it doesn’t! The car is almost completely unresponsive to the steering wheel necessitating a switch back to the nunchuck for steering.

Once you’ve won a race you can sit back and watch a replay of your triumph. Or can you?

For a start pressing A on the remote to continue after a race is often misinterpreted as a double press which takes you right past the replay menu and out to the race menu again. At this point you’ve lost the ability to watch the replay. If you do get to watch a replay the results are very poor:

  • The replay is often jerky so you twitch round corners rather than gliding round them
  • Again there’s no improvement in the overall video quality, no highlights or clouds of dust
  • Your vehicle will have a shadow; but the AI vehicles often have no shadow at all which looks weird and is just sloppy programming
  • If your car leaves the track and flies though the air it carries its under body shadow with it which makes it look like it’s flying on a big sheet of something. Poor!

The final nail in the games coffin for me is that most of the replays terminate before the race is over so you never get to see yourself cross the winning line. How naff is that? I’m not sure; but it might be dependent on the particular track. On at least one replay I watched it ended half way round the last lap. !?!

I think the only saving grace for this game is the sound track which contains some pretty catchy rock tunes without too much grunge. So while you’re waiting for your race replay to end prematurely you can at least listen to a nice ditty. This earned the game its second star.

Finally I have to say that as a racing experience Dirt2 way, way better than Mario Cart Wii and for that reason I’ll continue to play it; but come on Codemasters, you can do better than this.

 

Rated 2/5 on Sep 15 2009
Vote on David Hollingworth’s reviews at LouderVoice

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