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  • Installing Ubuntu on Eee PC 1000

    Published April 27th, 2009

    I decided the other day that I wanted to try to install Ubuntu on my Eee PC 1000. I’d already replaced the default Xandros Linux that comes pre-installed with Windows XP (because my other half needed it) but recently I’ve become annoyed with its tendency to seize up every now and again for no apparent reason.

    So I downloaded the Ubuntu Netbook Remix, and set about installing it as a dual-boot option. It was very simple, following the instructions took around 40 minutes for the entire process and it all seemed to be going fine. But when I came to reboot, there was no sign of Ubuntu.

    Now, the Eee PC 1000 has a 40GB SSD (Solid State Drive) — which is in fact two drives, one of 8GB and one of 32GB. The 8GB is the ‘primary’ drive, and that’s where Windows is installed, but there wasn’t space for me to install Ubuntu alongside it so I created a small partition for it on the ‘secondary’ drive.

    I guessed that the problem was probably related to this fact so I had a poke around to see what could be done. Checking the Eee’s BIOS, there’s no distinction between the two drives so you can’t choose to boot from the secondary drive. I was tempted to give up at this point (I didn’t seem to be able to find any useful info on the web), but since the install process is so quick I decided to have another go and see if I could spot anything along the way that might be of use.

    Sure enough, right near the end of the setup process (after creating/assigning partitions) there’s a little button labelled ‘Advanced’. Clicking on it popped up a dialog window with a drop-down list that allowed me to assign the boot loader to the primary drive (/dev/sda) instead of the secondary drive (/dev/sdb) that it had defaulted to. So I let it go ahead and install, and one reboot later there it was: a list of boot options. Success!

    So, is it any good? Well, it certainly looks good and I like the ‘remixed’ desktop/interface which organises applications in a sensible and easy-to-find way. Boot time isn’t noticeably quicker than WinXP, which is disappointing but could be explained in part by the fact that it’s running on the slower secondary drive. From what I can tell after one day’s use, once started it runs very smoothly with apps launching very quickly and no unexplained ‘freezes’.

    As far as compatibility is concerned the wireless, sound, touchpad, camera, display, USB and SD ports all worked out-of-the-box with no configuration required. I have my doubts that Bluetooth is working but haven’t had a chance to test it yet. The one serious gripe is the time it takes for the wireless to establish a connection — it suffers here even in comparison to Windows, which would (re)connect almost instantly where Ubuntu can take 40 seconds or more. I often use the netbook for a very short time (say, to do a quick web search) and then put it into hibernate, so a slow restart is a definite annoyance.

    If you’re interested in checking out the Ubuntu Netbook Remix but don’t want to go to the trouble of installing it, then you can run it from a USB stick (1GB or bigger) without any installation. Startup is slow but once it’s going it’s fine and if you decide you do want to keep it, then you can install it from the same USB stick.

    MySQL UPDATE with SELECT on the same table in the same query

    Published January 29th, 2009

    I’ve been having a week where there’s a ton of stuff to be done in a short time, yet everything seems to take much longer than it should and every task seems to present multiple unforseen obstacles. 

    Yesterday, for example, I was working on something that had already taken several days of my time when I’d hoped to get it done in hours. The final straw came when I found myself facing what appeared to be an intractable problem: a process that needed to insert multiple rows in a table, and increment a certain column in each row to get a unique value. I couldn’t use an auto-increment value in this case (there was one already), and using a separate query caused concurrency problems (resulting in non-unique values). I should just point out that this is a system that I’ve inherited, not one that I developed myself.

    I started out with a simple update, like this:

    UPDATE my_table SET some_value = ( MAX( some_value ) + 1 ) WHERE id = 123;

    …which in hindsight was never going to work but anyway, it gave me this error:

    #1111 - Invalid use of group function

    So I thought about it a bit and then struck on this:

     UPDATE my_table SET some_value =
    (
    (
    SELECT MAX( some_value )
    FROM my_table
    ) +1
    )
    WHERE id = 123

    …which gave me this error:

    #1093 - You can't specify target table 'my_table' for update in FROM clause

    …damn. I was starting to bang my head on the desk at this point, but Google came to my rescue by pointing me at this thread, which suggested using a nested sub-select. The result was the following rather ugly query:

    UPDATE my_table
    SET
    my_value =
    (
    (
    SELECT selected_value
    FROM
    (
    SELECT MAX( my_value ) AS selected_value
    FROM my_table
    )
    AS sub_selected_value
    )
    + 1
    )
    WHERE id = 123

    …which works. It’s not great  from a performance point of view since it uses a temporary table, but it does what it needs to. I hope in future that I will be given time to go back and rewrite this part of the system so as to entirely remove the issue.

    Enhanced (‘encouraged’) blog commenting

    Published January 12th, 2009

    Here’s a great blog post discussing a technique to simplify and encourage commenting on a blog, in particular by quoting text snippets. I might well try to find the time to implement it here on StickBlog.

    Comparing changes to MySQL databases

    Published December 10th, 2008

    One of my personal nightmares goes as follows: I’m working on an existing MySQL-based system, adding or changing something that involves altering existing database tables. I do what I need to, commit the code and then realise that I need to make the database changes too…only I’ve forgotten to keep track of the edits I’ve made. Oops.

    Now there are various things I should do to prevent this happening — at the very least keep a list of changes as I’m going along, which I do…when I remember to. But on those occasions when I don’t, I usually end up dumping the schemas and comparing them using a diff tool, which works just fine but can be rather laborious.

    Today I stumbled (via DZone) upon a piece of freeware called Toad for MySQL. It does a whole bunch of useful things, but the feature that stood out for me was its ‘schema compare’ tool. At first it looks like a dolled-up diff tool, but then you notice that in addition to showing you the differences between two databases, it also creates an SQL statement to convert between the two. Very handy.

    For those of you who are allergic to MySQL, there are versions of Toad for Oracle, SQL Server and DB2 (although they’re not freeware).

    jQuery: Dropping items from a draggable list to a sortable list

    Published October 4th, 2008

    For reasons that I might outline in another post sometime, I recently decided to replace MooTools as the JavaScript library behind our company CMS (which I’m in the process of rewriting from scratch) with jQuery.

    It’s been a few weeks now since I made the decision and I’m starting to become more comfortable with jQuery’s quite different approach. I’ve also begun working on some of the more complicated aspects of the new CMS, including adopting jQuery UI to provide the interface widgets. One requirement of the system is to have a dialog where search results can be dragged and dropped onto a sortable list.

    At first I looked at using two sortable lists and the built-in ‘connectWith’ option, which enables you to link two or more sortable lists together. But then I realised that I didn’t really want the search results to be a sortable list. In fact, what I wanted was a static list whose items could be dragged and placed in the sortable list.

    I tried a few experiments, and when those failed I decided to try looking at the code itself to see if I could hack together a solution without too much extra effort. While browsing the ui.draggables code, I stumbled across the intriguingly-named ‘connectToSortable’ option. I was surprised to find it because there’s (currently) no mention of it in the documentation, and indeed it’s very hard to find any reference to it at all beyond the code itself (the only useful link I could find was this one, but it rather over-complicates the issue).

    It’s very simple to use: as with connectWith, just specify which sortable(s) you want to connect to with the connectToSortable property:

    $('#myDraggable › li').draggable({helper:'clone',connectToSortable:'#mySortable'});

    Full example code here.

    The code for the example works just fine, but I found when using it in my own project, for some reason it was necessary to add a $(‘mySortable’).sortable(‘refresh’) call after defining the two lists, or the first drop operation would always fail.

    By the way, when fiddling around with JavaScript experiments I find JSBin very useful — you can load up any of several JS libraries (jQuery, MooTools, dojo, prototype, YUI, script.aculo.us) and create both JavaScript and HTML to test in a ‘live’ environment. Very handy.