Blog

  • Dimensionally Modelling A Recursive Hierarchy


    Creative Commons License photo credit: gadl

    I was recently asked how to include a recursive hierarchy into a dimensional model.

    What do I mean by a recursive hierarchy? This is when an entity (a table) relates to it’s self. Take the following example from an Oracle database:

    EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
    7369 ‘SMITH’ ‘CLERK’ 7902 ’17-DEC-1980′ 800 NULL 20
    7499 ‘ALLEN’ ‘SALESMAN’ 7698 ’20-FEB-1981′ 1600 300 30
    7521 ‘WARD’ ‘SALESMAN’ 7698 ’22-FEB-1981′ 1250 500 30
    7566 ‘JONES’ ‘MANAGER’ 7839 ‘2-APR-1981’ 2975 NULL 20
    7654 ‘MARTIN’ ‘SALESMAN’ 7698 ’28-SEP-1981′ 1250 1400 30
    7698 ‘BLAKE’ ‘MANAGER’ 7839 ‘1-MAY-1981’ 2850 NULL 30
    7782 ‘CLARK’ ‘MANAGER’ 7839 ‘9-JUN-1981’ 2450 NULL 10
    7788 ‘SCOTT’ ‘ANALYST’ 7566 ’09-DEC-1982′ 3000 NULL 20
    7839 ‘KING’ ‘PRESIDENT’ NULL ’17-NOV-1981′ 5000 NULL 10
    7844 ‘TURNER’ ‘SALESMAN’ 7698 ‘8-SEP-1981’ 1500 0 30
    7876 ‘ADAMS’ ‘CLERK’ 7788 ’12-JAN-1983′ 1100 NULL 20
    7900 ‘JAMES’ ‘CLERK’ 7698 ‘3-DEC-1981’ 950 NULL 30
    7902 ‘FORD’ ‘ANALYST’ 7566 ‘3-DEC-1981’ 3000 NULL 20
    7934 ‘MILLER’ ‘CLERK’ 7782 ’23-JAN-1982′ 1300 NULL 10

    From this we can see that there is a recursive hierarchy within this table between the empno column and the mgr column, the mgr column shows the employee that is the manager for each row.
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  • Backwoods Survival

    Sarah, Connor and I just spent a fantastic day with Patrick McGlinchey from Backwoods Survival School on the outskirts of Glasgow.

    We started off the day with a discussion on what “Backwoods” actually means and how it’s as much about preparing your mind as it is your body and your kit. Patrick was able to describe just about every plant, weed, shrub and tree that we passed and gave us the chance to sample all of the edible morsels that we could find as we walked through the woods. We also discussed the materials that could be obtained and what could be made from them, this included everything from cordage to fish traps to which wood was the hottest and brightest to burn.

    We then had a long talk on knife safety as much for my benefit as for Sarah (12) and Connor (8). It was then time to put these skills to the test. Connor had chosen to make a bow and arrow whilst Sarah and I would be making a fire bow. Again plenty of time was spent showing us the steps required. One of Patrick’s principles is to learn by doing. He may well show you how to do something, but you don’t take what he starts and finish it, you have to reproduce the steps he has shown you. This obviously takes a little longer but is MUCH more rewarding.

    Now The Arrow

    The only complaint that I could possibly have is that; as I had to pay so much attention to completing my own task, I completely missed the finer details of how to make arrows. I’ll need to see what Connor remembers. The only bit I picked up on was using dried dogfish skin to sand the shaft.

    Our creations complete, it was time for a well earned (I thought) cup of tea. Patrick demonstrated fire starting using a fire bow and also using flint and steel in conjunction with some fungus.

    First the fire, THEN the tea !

    After the tea it was time to put my firebow and my stamina to the test. I did manage to get it burned in. I did manage to produce smoke. I even managed to burn my finger, by poking it in to “see how hot it was”. The main thing I was struggling with was bowing level, so i was a bit stop and start. I will be practicing this over the next few weeks.

    Next it was time to “hunt” for our “dinner”. Patcick had brought along one of his hand made blowpipes and we took it in turns to pop a handily placed balloon. Despite my previous reputation as a blowhard it was Sarah who had the best combinatio of puff and aim.

    It was then time to head back to the car, sampling some more nibbles on the way and also giving Connor a chance to try out his bow and arrow in an open field.

    All in all a fantastic day, proof of the pudding, the kids want to go back again. I am going back, I have booked to go on the next available Backwoodsman course which lasts a whole weekend.

  • Emma’s Progress

    Not a lot of updates on Emma’s progress recently so here we go.

    Emma’s power in her arms and wrists has deteriorated severely over the last few weeks.
    This we have seen coming  for a little while, we have been helping her to eat for six months or so.
    The biggest impact this is having is that she can no longer use the keyboard on her laptop: so her online presence on Bebo and MSN has been brought to a premature end.
    She has already been assessed for alternative input tools such as an eye controlled system. This happened when she was last at Rachel House so I never got a chance to find out more.

    More worryingly the muscles in her throat are starting to weaken so she has started to choke on her food occasionally.

  • September Weekend Holiday

    I have just realised that it has been ages since I have posted here.

    It has been a fairly uneventful holiday so far. Did some decorating:

    • Connor’s bedroom ceiling (he has not chosen main colours yet)
    • Main bathroom
    • Upstairs Hall
    • Stairs
    • Downstairs Hall
    • Downstairs Bathroom.

    All painted.

    Time for a day off now.

    Tomorrow, myself Connor and Sarah are off to meet Patrick McGlinchey he is the main instructor at the Backwoods Survival School.

    I’ll update here with all of the things we cover.

    Ross

  • Selective Colour

    I suggested a possible change to a Flickr friend’s photo.

    From

    To

    You can see the original here.

    I thought it would look better fully monocrome with just the lips and the flowers in their original colour.

    Here is how I did it.
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  • Changes to this site

    I got some time to spend on this site this evening.

    The most obvious change is the visible one, I have changed the theme to the Mogle theme, I like the three column layout better than the old two column layout. I also prefer the black, white and orange scheme.

    The next visible change is the addition of the Subscribe2 plugin. If you register as a user of this site you can receive an e-mail alert when new posts are made. Alternatively you can just stick with the RSS feeds. There are made more prominent by this theme as well.

    The last change is  the addition of the WordPress.com Stats plugin which will allow me to see how many visitors I get.

  • Twitter Muted

    Took me ages to work it out.  Normally when I post to my site it updates my Twitter.

    I had changed my Twitter password and forgot to update it here.

    Numptie

  • Titan Crane

    We were supposed to be going to see the Titan Crane on the Clydebank today.

    Unfortunately it was such a miserable day we never even braved out the front door.

    We will try and get there next weekend instead.

  • Airshow at East Fortune

    Went to see the Scottish Airshow at East Fortune.

    The kids favourite was the Hunter

    Miss Demeanour's bottom

    The obvious favourite was the Typhoon
    Eurofighter Typhoon 5

    My personal favourite was the Chinook helicopter

    Everyone holding on ?

    For all of the photos, look here.

  • Connected On The Move

    I finally figured out how the e-mail works on my mobile phone.

    I could always receive messages on my phone but I could never reply or send.

    It was an off the cuff remark on a forum post that triggered the lightbulb moment. I can only send via my ISP’s mail server if I am connected via my ISP! Obvious with hind sight !

    All I have to do is send all my messages via the Orange mail server.

    Works a treat!
    (more…)