Monday, December 08, 2008

UKOUG2008 - Thursday

People kept telling me Being Steven Feuerstein was a striking presentation title. Although, as Niall Litchfield observed, James Morle's Driveheads revisited was pretty cool too. The thing about snappy titles is that they need to convey something about the subject matter as well as being funny, so I think James just edges it on the informative side.

The presentation had proved to be one of the hardest I have given, both in shaping the material and then in getting it down to 45 minutes. I went through it seven or eight times and it always took an hour. It was like a cartoon parcel: every time I pressed down on one bit another bit ballooned out. In the end I found myself in the hall just dropping whole chunks and hoping. I got to the wire with two minutes spare for questions (better than some other speakers I've seen this year).

My key insight into coding standards is that they don't make us better programmers. A program can be the acme of applied coding standards and still be functionally incorrect and bug ridden (although unit testing and code reviews should make that unlikely). More obviously a program can correctly implement the requirements and be bug-free yet fail to meet any set of coding standards whatsoever. No, the point of coding standards is to make us better team players, so that our programs play nice with programs written by other people. It's all about maintainability.

There was no time to relax after I finished because I had another session almost immediately. This session was difficult for another reason. I'd proposed the title Designing PL/SQL with a view to doing something different, something interactive, a sort of workshop. I'd prepared some design exercises with a view to stimulating some thinking. In hindsight I hadn't given enough thought to how I was actually going to run the session. In particular I hadn't got an ending, so it just fizzled out. It would have been a lot easier to give the session a shape if I could have topped and tailed it with some slides. But I chose to use the round table area so that people could talk and work together but it has no AV facility. So no Powerpoint. Also the exercises were too hard for people who had no experience in the sort of design decisions I wanted to explore, which seemed to be almost the whole audience.

So I await the feedback with interest. I don't know whether anybody else learned anything. But I certainly got some lessons in running interactive sessions. They are much harder than they look, because you need to put in just as much thought and preparation as a regular guy-plus-slides session, but rehearsing them is a trickier proposition (it's not really the sort of think you can do in a hotel room on your own). Still, the people in the UKOUG back office were supportive of the experiment, so I think I might have a second attempt at something like this next year. In the meantime, there are no slides to download for this session (obviously) but I will try to blog the exercises later.

After that session a couple of people asked me about automated unit testing, so I spent some time discussing testing in general and utplslql in particular. It made a change from evangelising to the uninterested, which is the more usual case. So I missed the start of Robyn Sands's talk on Root Cause Analysis in the service of reducing a support DBA's workload. She discussed the Five Whys as a technique for discovering what problem underlies an error message, the Ishikawa diagram for analysing all the possible sources of error and Pareto charts for seeing where most of the pain is. I particularly liked the way she redrew the Ishikawa fish to reflect a database scenario rather than its manufacturing origins.

The object is to fix the issues which will reduce the greatest number of calls, rather than reacting to the immediate symptoms. We all know thinking is good, but it can be hard to resist the pressure to resolve the surface issue and move on to the next ticket. Robyn was discussing a project she worked on which was dedicated to just eradicating persistent deep sources of bugs. The fact that this was a special project shows how hard it can be to resolve things properly in the real world.

My final task of the conference was chairing my colleague Roel Hartman's presentation on ApEx. This discussed a project to convert an archaic existing application (written in an obscure metadata-driven tool) into ApEx. The converted application had some neat features, including a good-looking planning tool with drag'n'drop. My concern is that Roel's presentation featured lots of JavaScript. How long can ApEx maintain a reputation for productivity when we still have to resort to bespoke coding for features as mundane as user-friendly calendar widgets and multi-column LOVs?

The contrast with Duncan Mills's session on the Fusion development platform earlier in the week is instructive. Duncan was discussing how the Fusion Apps developers are using JDeveloper. They operate under two rules:
  1. Write no SQL
  2. Write no JavaScript
The new generation of Oracle Applications are being assembled out of pre-built components and metadata driven frameworks. The range of JDeveloper widgets is comprehensive to the point of confusion (if you want to build your only implementation of MS Project JDev offers you a menu of Gantt chart components) but the results can be astounding: check out the Cuyahoga County GIS application.

Wednesday, December 03, 2008

UKOUG2008 - Wednesday

The big topic of conversation has been the credit crunch, and what impact it has had on the conference. Certainly there seem to have been more cancelled sessions than in previous years. And the exhibition hall seems emptier. The striking feature is the absence of many stalwarts of previous years: no Microsoft, no Dell, no Quest, no Sun. Another feature is the complete absence from the stands of - and there is no PC way of putting this - dolly birds. It's all techies in polo shirts and marketeers in smart suits.

At least IBM still showed up. Their barista provides the only decent coffee on the site.

Actually, there is a presence from Sun: they have a stand for MySQL. I complimented the guy on his bravery. He said that 75% of Oracle users are also MySQL users, which is an interesting statistic and may even be one that he hasn't made up. He gave me a MySQL keyring, so I'll give him the benefit of the doubt.

I went to see Mogens Norgaard do one of his idiosyncratic turns. He was as deceptively rambling and unfocused as ever, leavening his talk on goats and beer with many perceptive insights into our industry today. Mogens gives presentations like Les Dawson played piano: with consummate skill and exquisite timing. "We are all legacy now.... Look around you". Supporting his assertion that "Databases are legacy" he quoted an Oracle product manager at the ACE Directors' briefing from this year's Open World who claimed Coherence offered "zero latency" and "infinite scalability". Why are these people building middleware when clearly they should be building the spaceships that will take humanity to the stars?

I chaired Sue Harper's presentation on Visual Data Modelling using the SQL Developer Data Modeler tool. One of the doubts I had when Oracle purchased the CDW4ALL tool was regarding the business sense in buying a product only to give it away for free. Sue answered that question today: Oracle are not going to give it away. Although it's part of the SQL Developer brand it will be a licenced standalone product. Although there will be a free extension to the SQL Developer IDE which will allow developers to read OSDM models. Sue was demonstrating the EA2 release, which looks to have fixed a number of issues from the first release. In fact the whole tool looks very nice. In some ways it is a distinct improvement on Designer. The date of the production release is dependent on building a repository for the tool (currently everything is file-based). This shows that the team really is showing the same responsiveness to the product's users as they have shown with the SQL Developer IDE itself.

Words of wisdom from the bottle of Rittman-Mead beer I'm drinking as I write this: "A consultant is a man sent in after the battle to bayonet the wounded." Almost as true as this.

UKOUG2008 - Tuesday

The water tastes funny. This is not just a Londoner whinging about leaving his comfort zone, other people have commented on it too. And it's not just the water in the ICC it's the water in the hotel too. Perhaps it's time to resort to the medieval practice of drinking beer all the time.

Or then again perhaps not. People stopping by the Rittman-Mead Consulting booth can sample their branded beer (lager). Indeed beer will be pressed upon them. It's not bad but I totally blame Mark's beer for what happened next. I was chairing Steven Feuerstein's session on Weird PL/SQL. We were chattting about this and that when I glanced at my watch and noticed that the session should have started three minutes earlier. Tut tut. Steven's session was further interrupted by a screen blackout but he's a trouper and coped admirably. His presentation focused on some the quirks in PL/SQL. For instance are exceptions negative or positive? The answer is, it depends. Most are negative, execpt USER_DEFINED_ERROR and NO_DATA_FOUND. And then some of the built-in PL/SQL utilities store them as positive numbers. He also showed us some features in PL/SQL which had been implemented but not quite finished.

More fun was poked into Oracle in the next session I attended, a double bill from Hugh Darwen and Toon Koppelaars on DB Constraints, A Woeful State Of Affairs. Hugh led the attack. He had set his undergraduate students an exercise in modelling a simple banking application in two different ways. The first approach was to use Tutorial D implemented in Rel, which is a fully compliant relational language, and the second approach was to use Oracle SQL 10g, which is not. There were three things which Oracle could not implement. The first was enforcing the rule that a Customer must have an Account. The second to ensure that a Customer could have several different phone numbers but only one of a given type (Home, Work, Mobile). I'm not sure about this one, as I think it could have been modelled differently and in a way which Oracle could support, but I'm not going to cross swords with a modeller of Hugh's experience. The third hitch concerned outgoing transactions: payments with a cheque or credit card use the account number but paymenst with a debit card use the card number instead. The first two problems were due to DBMS vendors not implementing features in the SQL standard (such as CREATE ASSERTION) but this third was due to a peculiarity in Oracle's implentation, which don't allow compound unique indexes to have multiple null values in one of the columns.

Toon was responsible for defending the position of the vendors with regards to assertions. He did this by walking us through the complexities involved in enforcing the rule "If a Dept employs a Mgr or a President it must also employ an Admin". The basic principles are quite straightforward, the difficulty lies in tuning the rule so that it doesn't completely kill your application. For instance, you don't need to run the rule if you're inserting an employee who's not a manager or if you're deleting an employee who's not an administrator. I guess the place where Toon was heading is the difficulty of enforcing such rules in a multi-user environment. Unfortunately, the session overran with the start of the focus pubs, which as a SIG chair I had to attend. So I'll have to wait until I download his presentations to discover the denouement.

The stated aim of the focus pubs is networking: to allow delegates to meet the people people who run the SIGs and for us to badger them into doing presentations. Unfortunately the ambience is more like a nightclub than a pub: dim lighting so you can't see anybody, loud music so you can't hear anybody. Thus you end up mainly talking to people you already know. But that's good too.

Tuesday, December 02, 2008

At last, the UKOUG show

I have been very busy recently, too busy to blog. Although I do have a stack of half-finished articles which I will finish off in the coming months. Mainly it's been work pressures: I'm coming to the end of my stint on my current project so there's been lots of tidying up and handing over to complete.

But also I've been working on two presentations for the UKOUG. One is stressful enough. The presentations are back to back on Thursday. The first is a regular presentation, called Being Steven Feuerstein, and it's a meditation on PL/SQL coding standards. I don't think Steven himself will be attending, which is a relief but also a disappointment as I was hoping to stage a PL/SQL version of the "I'm Spartacus!" scene. The other presentation is a more experimental session called Designing PL/SQL. It is in the round table area but it's not a round table. It's more of a Workshop.

Birmingham is its usual Christmas-y self, complete with street decorations in the achingly fashionable blue and white colour scheme. In fact it's been snowing, which I think is taking Christmasiness too far. I don't fancy negotiating the canal-side walkways once the slush has frozen over, particularly tonight, what with the ACE dinner following on from the focus pubs. I think I might skip into town to replace my work shoes with something more in the Timberland line.