Today my normally silver car has a more golden-bronzy tinge, or a thin film of volcanic dust. Part of Iceland is now travelling around the streets of Milton Keynes attached to my car, a sort of grimy hitch-hiker.
I should not really know about the dust on my car as I should not be in England, I should currently be mid-Atlantic on my way to speak at a conference in Las Vegas. But that is not to be. Optimistically, I followed the hour-by-hour announcements from the airline and the NATS air traffic service right up to the time I was texted with my flight cancellation. I have now cancelled the flight booking (there was no point rebooking to arrive after the conference finished) cancelled the hotels, briefed a colleague in the hope that he could give my talk. I have even been to the supermarket to buy food (what is the point of food in the fridge if you are away?)
There is no point ranting about a volcanic eruption blocking air travel to or from north-western Europe, these things can happen (obviously). I am one of the fortunate people, I am still at home, my journey, although long anticipated, is not critical in course of world history. Yes, I was invited to speak at a conference in the USA; yes, I would be representing and publicising my company; yes, delegates have told me that they would like to meet with me and talk; but my not being there will not stop the conference. And, as I said an American colleague at the conference may be able to give my talk for me.
I am a lucky one; I have friends and colleagues in the USA trying to return to Europe, friends in Denmark (amongst other places) trying to cross the Atlantic to get home, and friends dotted around northern Europe just trying to make it home to the UK. One friend is in Northern Italy singing with a choir, tomorrow she should fly home to be with her children and ready to return to the school she teaches at on Monday – but that won’t happen, and I can think of no quick way for her to return from the wrong side of the Alps.
Some might think that having no flights is as if aviation had not been invented and we can proceed with a more sustainable, low carbon-footprint, way of life. True, it is technically feasible for me to do my job by the wonders of telephony and the internet, I could video-conference my presentations, I even could go to the pub and phone my colleagues so that I can take part in social interaction outside of the office over a few beers. But powered flight has been invented and the suddenly switching it off for several days is not the same thing; people have not planned there lives in anticipation of this and the event causes big problems to those who just need to get home, those that would not be where they are if a plane had not taken them there.

I am sitting in a train travelling to the North West of England and using the at seat wifi connection. This service is provided by T-Mobile, a brand with a global presence an major UK mobile operator. “So what?” I hear you say, the problem is that the internet connection from the train surfaces in Germany – and hence I get Google Deutschland, LinkedIn and Facebook with German Language content, all of which I can cope with – but what drives me nuts is that I for some sites content is blocked that is not relevant to the ISP location and that is not my location…

For various reasons I have gained a reputation in data warehousing – whether it is from my older blog posts, speaking at conferences, or my role in a high profile BI consultancy, I am not sure.

One outcome of this is that I get asked to take part in various activities to promote new products; PR companies write (perhaps under the mistaken impression that I am a real journalist) to invite me to interview some CEO or CTO of a software company to discuss a new product; I also get invited to try new software, either at launch or as part of a beta program.

Recently, a software company (NOT Oracle, hence I write here on my personal blog, and not the company one) invited me to try their beta release BI database. There are a lot of innovative features but one really caught more eye as a one of boosting performance without breaking the hardware budget: the UNGROUP BY clause.

Readers of my postings on my employers blog, or attendees of my DW design courses will know that I am strong advocate of the principle that IO throughput is the biggest constraint on DW performance. You need the right capacity of disk, the right number of IO channels working at fast enough speeds (fibre channel, InfiniBand etc.), some vendors move some processing close to the disk so that smaller (skinny?) result sets are passed over the wire to the CPUs. Other database vendor-specific techniques centre on the use of segment compression and partition elimination to reduce the number of bytes brought from disk to answer the query. But for all database vendors the traditional way of reducing IO is to fetch back “summarised” data that answers the user’s query. But until now there was no way back from the aggregated data to detail. BUT, for this database vendor’s product. Is no longer the case.

Suppose we have a table of total sales by year for our international company and we need to get the yearly results for each country – simple we just execute:
SELECT country, sum(sales_value) from GLOBAL_SALES UNGROUP BY country
need those sales broken down by quarter as well then:
SELECT country, quarter, sum(sales_value) from GLOBAL_SALES UNGROUP BY country, quarter ORDER BY country, quarter.
“This looks magic, can we use it for any query?” Well there are some restrictions; the column names used must match the key column names defined in dimension objects (the next release will also support unique attribute matching), there must be a column in the table to be ungrouped for the parent key – that is, we we need an ALL_GEOGRAPHY column in table, we can’t rely on the fact that the column is not there to assume the total level. There is also a practical limitation on the number of levels you can drill to using this query – two levels. So ALL_GEOGRAPHY can drill to region and country, but not to state or city.
Under the covers we use a novel kind of composite “index” to assign a “proportionality” to the dimensional components, this is the really clever part as the index uses bitmap semantics to provide a compressed array of proportions.
Early days in testing this feature but I am impressed.

Late breaking news – Just been told that this is an April Fools posting and should not be used as part of a functional specification

I am very conscious that I have not posted much on this blog recently. In part the technical stuff has been surfaced through the company blog – I get in to trouble if I say Mark’s blog because it is the company one now, an in part because of a load of domestic events have stifled my available creative time.

Still, on-site with a customer in Greece has given me an unexpected amount of online-in-the-hotel-in-the-evening time which I can fill with research or just writing this stuff.

I had always wanted to visit Greece but as I am not a sand-n-sea person it would not be for the islands and beaches, but more the ancient history. So working here and having a weekend in Athens (and not one where I am scheduled to fly to London or San Francisco – which is the case for all the other weekends before Christmas) gave me the ideal chance to see the Acropolis and other historic sites nearby. Put simply, I was stunned by it all. The scale of things, the age of things… the sophistication of the art and the science. It makes you wonder why or how Western Civilisation did nothing from before the fall of Rome until, well, 160 years ago.

I think I can understand the concept of the Grand Tour now!

Last Sunday was the end of the daylight saving scheme that goes in these parts by the name of British Summer Time, today 2 days past the end of summertime it snows!

I don’t recall snow so far south in October. Oh well it gives me something to write about!

Seemed to have spent a lot of August travelling. A short-term engagement in a Nordic country and the family vacation let me put on more than my fair share of air miles. The final flight (I hope!) of the month was yesterday when I took my 17-year old to Aberdeen to visit the university. It seems so tiring to get the 7:00 AM flight and then spend most of the day walking around before the 8 PM flight home. Still it was a great day out and nice to get back to Scotland. My Daughter loved the University, so who knows, Aberdeen may become a regular destination for me!

Not written much for a while – or so a dear friend tells me in an email

I have been busy with some consultancy for a non-BI customer and then several days learning to deliver a training course that a colleague produced; well at least build my virtual machines for the exercises and making sure that I can get the examples to work. I also learned how to shrink a VMWare Fusion virtual machine when there is not enough free diskspace on the host to use the shrink tool!

So, what goes on at Scott Towers? The elder girl is looking at colleges for 2009 and like all teenagers wants to get as far as possible from home – in the UK that is not that far, but she has ambitions – OK, she has now decided against going to Canada to study on cost grounds, but her potential choices in Cornwall, Scotland and North Wales are all a long drive from here. Be glad when the last open day is done!!!

Before she goes to university there is that final year of school. She has started to ask me for help checking her work for chemistry (I knew that degree of mine would be useful one day) and asking for help on her database project for IT… think though she is asking the wrong person for help on normalisation (I said that to prevent others – Doug – from doing so!)

It’s a holiday weekend in England and that means our local shopping centre is hosting yet another collector’s fair. Unlike the others there will not be a Dalek, Wookie, Blake’s-7 cast member in sight, and probably none of those autograph hunters that actually look like Vogons, Klingons or extras from the Lord of the Rings. Instead, it is a collection of geriatric retired sportsmen (but probably still fitter than me!)

I guess my colleague, Mr R, will be impressed that some of Spurs UEFA Cup winning team will be there (was 1963 really the last time Spurs won anything ) it impresses me too as Jimmy Greaves’ aunt used to live a couple of houses from me and Terry Dyson used to teach sport at my old school – maybe I’ll go and look them up… maybe not.

I am currently in Paris getting ready to participate in a training course – makes a change to be trained, usually I am the one doing the training.

For me, getting to Paris is simple, I walk to my local station (less than ten minutes), catch a train to London (about 30 minutes) then the short walk to the Eurostar terminal and catch the Paris train. Less than two and a half hours later I would be walking in Parisian streets on my way to the hotel. The same journey by air would be a lot more convoluted with driving, parking and airport shuttle buses added into the mix. And if I go with a budget carrier no food – unlike my ticket today which gave me a meal and wine on the journey and way too much coffee.

So why do I need a new passport, well it’s got a couple of years to go before it expires, it is machine readable so I can get in the USA on a visa waver but the significant thing is the photograph – today the French border police took one look and smirked…

If only we were in Schengen zone then I would not have such hassle!

Readers of the other blog, the more technical one, will know that I have been at Collaborate 08 in Denver, CO. I’ll write about the presentation itself over on the Rittman Mead blog – and I’ll post up the paper so that the interested can take a look.

When I was booking my flights I found that I could get a good deal on flights from British Midland and using the direct United Airlines route from London to Denver, especially as I could part pay in frequent flyer points. I suppose that seats are perhaps slightly smaller that BA’s but for a person of my modest stature it doesn’t matter that much. The plane flies quickly, the meals are not toxic and at the end of the day all I am doing is travelling so is there any value in paying for ‘extra comforts’?

The out bound flight was a few minutes late leaving (unlike Mark’s flight with BA which was cancelled) but we more than made up time on the journey. By one of the odd, small world things the passenger next to me was also going to a conference in Colorado, but not my one, but the odd thing was that her department head when she was a PhD student was a friend of mine. Two meals and two snacks later we arrived in Denver and were told by the ground staff to walk as quickly as possible to the border control as another transatlantic flight was just 2 minutes behind and if we got to the hall first we would be out first. I guess it took just ten minutes to get to the head of the line and be processed and then on to the shuttle bus to the hotel.

The hotel was just across the street from the convention center and my room actually overlooked the large blue bear at the doorway to the halls, so little chance of getting lost later in the week. Forced myself to stay up to 9:30 PM (or 4:30 AM UK time) in the hope of getting more in the swing of US time – did this by sitting in the bar drinking cranberry juice and eating a pulled pork sandwich, If I stayed in the room I would have fallen asleep. The strategy didn’t quite work – I still woke around midnight and then seemed to wake hourly before deciding enough was enough and down for a 6:30 breakfast; then on to the convention center to pick up the bag, tee-shirt, water bottle and speaker gift before braving the hotel gym followed by a short walk along the 16th Street Mall to find a store that sold Fruit Loops… don’t ask!

First event of the conference was a speakers induction session with a guest speaker explaining about giving impact followed by the SIG social which gave me my first chance to meet strangers – bumped into Jeremy Schneider whose blog I dip into – nothing wrong with a DWer being widely read! Towards the end of the evening Mark rang to say he had arrived (24+ hours late) we agreed to meet for breakfast the next morning which again turned out to be at 6:30 AM…

Mark and I have written about the technical sessions and the move from heat to snow overnight so I won’t duplicate that here (except in the blog title, oh, and this paragraph) but you must not forget the social aspects of the conference – I met people that I only knew of through their presence on email or the internet, amongst others (and meaning to offend the omissions), Dan Norris, Ameed Taylor, the team from Vlamis Software Solutions, many of the Oracle product management guys; it was great to associate faces with them all. I also met up with old faces – the Apex Evangelists, Alex Gorbachev, David Kurtz (who used to live 500 yards (or metres would be close enough) from me in when we both lived in Reading), the various UKOUG folk.

Thursday and my flight home came too quickly – shared a ride back to the airport with John Scott and Dimitri Gielis – checked in to be told my seat will be allocated at the gate, declined the offer of an upgrade to business class for $250 (the bed seat may be worth while, but the ‘better’ food wouldn’t) as it happened I sat right at the back next to a chatty Colorado girl who promptly told me I had been drinking the wrong beer all week and it should have been ‘Fat Tire’. And I broke my Heathrow touchdown to home record – 2 hours 5 minutes from landing; that’s taxi to the stand, deplane (and I was right at the back) through border control, pick up luggage, clear customs, catch the train to London, cross to Euston and catch a train back to Milton Keynes then travel to my house