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Friday Philosophy – The One Absolute Requirement for System Success October 14, 2011

Posted by mwidlake in development, Friday Philosophy, Perceptions.
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Alternative title “The lady from Patient Admin – she says YEEESSSS!!!!!!”

What must you always achieve for an IT system to be a success?

  • Bug free? Never happens.
  • Within budget/time frame? That would be nice.
  • Includes critical business functionality? Please define critical.
  • Secure? Well, it’s important for many systems but then it is often lacking (even when it is important).
  • That it is to specification? Well we all know that’s wrong.

There is only one thing that an IT system must always achieve to be a success.

User Acceptance.

For an individual system other considerations may well be very important, but the user acceptance is, I think, non-negotiable.

The user must get enough out of using the system for it to be worth their while, otherwise at best they will resent using it and at worst… Well, at worst they will use it but will put in any old rubbish to fulfill the dictate that it be used. You would be better off if they did not use the system at all. Here are a couple of examples from my working past.

In the first one, I was involved in extending a hospital management system so that it kept track of the expected departure times for patients, allowing a predication of when beds would become available and calculation of expected occupancy rates. Yes, this was a while ago (maybe 1990) and on an a system that was old then. The information was needed by someone with the title “bed nurse” {or something similar} so that they could better prepare for bringing patients in and keeping a higher bed usage ratio. This was to make the hospital more efficient? No, it was to satisfy a politically demanded report to the NHS executive. Oh, the overall intention was to increase efficiency but the report soon became more important than the idea. So, we added columns in tables and field on screens and prompts for the ward staff to fill in the information. And they didn’t. The nurses were busy, they were pretty demoralized due to having recently been used by the government as a way to control public sector pay and they had nursing duties to do. They were not going to waste a couple of minutes trying to check when Mrs Jenkins was going to be sent home when Mrs Leonard needed a bed pan. The nursing staff were given a hospital-wide telling off, this information had to be entered. They put in the data – but guessed wildly. The design was fine, the report was logically accurate, only the correct staff could run it, but No User Acceptance and thus a failure.

So I added something else. It was a very crude screen that showed a “diagram” of the ward – Down the left and right side of a VT220 screen you saw little oblong boxes with a bed number, name in it, a consultant’s initials, a medical speciality code and the arrival and departure datetime. This was some information we already had plus the new information we wanted and something quite basic, limited and slow to draw. But it was useful to the ward staff. They could find any patient, they knew who to call if there was an emergency {not the actual consultant of course, but their secretary}, they could check when they were leaving, they could see what time someone was expected. From anywhere where there was a terminal, not just the entrance to the ward, they could see all this information. They used it.  They put in the expected departure time {sobering thought, this might not be expected leaving alive} and the bed nurse could plan and the report could be run.

Second example, different hospital. We were putting together a system to schedule outpatient clinics. We knew what we were doing, it’s pretty simple. You have some people (a consultant and probably a senior house officer), a period for the clinic (3 or 4 hours) and a set of people to see, say 40.  Give some flexibility in slot lengths (some people need 5 minutes, some 15) and allow the patients to be booked in. Check for and stop double booking. We did not go and ask the patient admin staff, we knocked up the design and the screens and asked them to test. After all, I was very experienced now, I’d been doing these systems for 3 years… They very quickly came back to us and said it was rubbish. Oh dear.

We went and saw them. I think it was a couple of us programmers, our development manager, the hospital liaison for the project and the patient admin staff. “What’s the problem?” There were a few but the main one was that you could not double book a slot. Why would you want to? Do two patients really want to be consulted at the same time with the same doctor?.
“Err, maybe, it might happen, can we just be able to double book?” OK, we could maybe alter things to allow two patients to be seen at the same time… The patient admin staff are not looking happy. The hospital liaison is looking confused – “You can’t do that! Patient confidentiality can’t be broken!” he says. It got worse. “We need to book all the patients into the first slot, with the consultant, so the letters go out to them saying come to see Mr Winders at 1pm”. The admin staff are now looking very shifty.

If any of you have worked in the health service you are probably way ahead of me. The admin staff needed to book all the patients in at this first slot so that they would all turn up, the consultant would see the two or three he was interested in – and then go and play golf. The SHO would then plough through the rest of the patients for the following three or four hours. If you have ever had to turn up at the start of a consultancy session and sat there for three hours, now you know why. You see, back then, the consultant was only a very small step away from deity level (and I leave it to you to decide if it was a step up or down). What they said went and if they wanted to go and play golf or store 200 medical records in the boot of their car or refuse to speak to “that stupid idiot in renal medicine” then you worked around it. {I’m assured that things are a lot better now, but I’d love to know how it really is}.

We had designed a sensible system, the users needed a non-sensible {to our mind} system. Even the NHS liaison chap had never appreciated exactly how much the consultants abused the system, he thought they just booked the people s(he) wanted at the start of the session, but no. The consultant decided that day who was interesting and as a result every patient had to be there at the start.

I count myself lucky that I learnt from direct experience so soon in my working life that (a) you have to deliver what the user will accept and (b) the only way to know what they want is to show them the system and talk with them.

{For those of you who do not understand the alternative title at the top, it is all about an old DelMOnte fruit juice advert which became a bit of a catchphrase at the time}

{And are you happy now Dom? :-) }

Friday Philosophy – The start of Computing October 7, 2011

Posted by mwidlake in Friday Philosophy, history.
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This week I finally made a visit to Bletchley Park in the middle of England. Sue and I have been meaning to go there for several years, it is the site of the British code-breaking efforts during the second world war and, despite difficulties getting any funding, there has been a growing museum there for a number of years. {Hopefully, a grant from the Heritage Lottery Fund, granted only this month, will secure it’s future}.

Why is Bletchley Park so significant? Well, for us IT-types it is significant because Alan Turing did a lot of work there and it was the home of Colossus, one of the very first electrical, programmable computers. More generally of interrest, their efforts and success in cracking enemy ciphers during WW2 were incredibly important and beneficial to the UK and the rest of the allies.

In this post, I am not going to touch on Colossus or Alan Turing, but rather a machine called the “Bombe”. The Bombe was used to help discover the daily settings of the German Enigma machines, used for decrypting nearly all German and Italian radio messages. All the Bombes were destroyed after the war (at least, all the UK ones were) to help keep secret the work done to crack the cyphers – but at Bletchley Park the volunteers have recreated one. Just like the working model of Babbage’s Difference Engine, it looks more like a work of art than a machine. Here is a slightly rough video I took of it in action:

My slightly rough video of the bombe

{OK, if you want a better video try a clearer video by someone else.}

I had a chat with the gentleman you see in both videos about the machine and he explained something that the tour we had just been on did not make clear – the Bombe is a parallel processing unit. Enigma machines have three wheels. There are banks of three coloured disks in the bombe (see the picture below). eg, in the middle bank the top row of disks are black, middle are yellow and bottom are red. Each vertical set of three disks, black-yellow-red, is the equivalent of a single “enigma machine”. Each trio of disks is set to different starting positions, based on educated guesses as to what the likely start positions for a given message might be. The colour of the disk matches, I think, one of the known sets of wheels the enigma machines could be set up with. The machine is then set to run the encrypted message through up to 36 “Enigmas” at once. If the output exceeds a certain level of sense (in this case quite crucially, no letter is every encrypted back to itself) then the settings might be correct and are worth further investigation. This machine has been set up with the top set of “Enigmas” not in place, either to demonstrate the workings or because the machine is set up for one of the more complex deciphering attempts where only some of the banks can be used.

This is the bombe seen from the front

The reason the chap I was talking to really became fascinated with this machine is that, back in about 1999, a home PC programmed to do this work was no faster than the original electro-mechanical machines from 1944 were supposed to have taken. So as an engineer he wanted to help build one and find out why it was so fast. This struck a chord with me because back in the late 1990’s I came across several examples of bespoke computers designed to do specific jobs (either stuff to do with natural gas calorific value, DNA matching or protein folding), but by 2000, 2002 they had all been abandoned as a general PC could be programmed to be just as fast as these bespoke machines – because bespoke means specialist means longer and more costly development time means less bangs for your buck.

Admittedly the Bombe is only doing one task, but it did it incredibly fast, in parallel, and as a part of the whole deciphering process that some of the best minds of their time had come up with (part of the reason the Bletchley Park site was chosen was that it was equidistant between Oxford and Cambridge and, at that time, there were direct train links. {Thanks, Dr Beeching}. ).

Tuning and reliability was as important then as it is now. In the below picture of the back of the machine (sorry about the poor quality, it was dim in that room), you can see all the complex wiring in the “door” and, in the back of the machine itself, those three rows of bronze “pipes” are in fact…Pipes. Oil pipes. This is a machine, they quickly realised that it was worth a lot of effort to keep those disks oiled, both for speed and reliability.

All the workings of the Bombe from the back

Talking of reliability, one other thing my guide said to me. These machines are complex and also have some ability to cope with failures or errors built into them. But of course, you needed to know they were working properly. When these machines were built and set up, they came with a set of diagnostic tests. These were designed to push the machine, try the edge cases and to be as susceptible to mechanical error as possible. The first thing you did to a new or maintained machine was run your tests.

1943, you had awesome parallel processing, incredible speed and test-driven development and regression testing. We almost caught up with all of this in the early 21st Century.

Friday Philosophy – Team Ice-Cream and Telling Offs September 30, 2011

Posted by mwidlake in Friday Philosophy, Management.
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If you manage people, it helps if they don’t dislike you. Sadly, this can be the default starting opinion for some people who have never been managers (we all know someone who “has never had a decent manager, they are all bloody idiots”). Frozen dairy products might be a route to easing this situation.

I mention this as we in the UK are having an unusually warm start to autumn, an Indian Summer as we call it. I used to work in a place that had an on-site cafe and a nice area outside to sit. If the weather was warm and I knew my team was not facing some crisis, I would occasionally pop my head around the door and announce “Team Ice-Cream!”. Anyone who wished could come down with me and I would buy them an ice-cream of their choice and we would sit out in the sun for 15 minutes and talk rubbish.

I’ve done similar in other situations. Taking the guys to the pub is the obvious one and it usually is appreciated, but in some ways it is less successful. I think this is because people will come to the pub because they want a pint and will put up with any idiot willing to provide a pint of Fosters (why is it so many of the “all managers are idiots” brigade drink some brand of nasty lager?). People will come for a tea/coffee or an ice-cream only if they are at least ambivalent to the provider. If you really dislike someone, who cares about an ice-cream? The serious malcontents will stay away and this helps identify people who really are not happy with you {so you can beat them mercilessly of course – or, if you’ve progressed beyond the school-yard, put some thought into why they are unhappy and what to do about it}.

By the way, this is very different to everyone going to the pub/restaurant in the evening and spending hours telling people what “you really think” and trying to impress Jessica the new trainee/intern. Such team building events generally need much more planning.

It’s a cheap bribe, should you resort to such shallow tactics to make people like you? Well, it’s only a cheap bribe as I said above. The trick to it is that it has to be {almost} spontaneous, such that the team are not expecting it, and not all the time. I’m not sure the teams I have done this for have always appreciated that I made special effort to do this either after a hard period of work or when there had been some malcontent within the team (people fall out, it impacts the rest of the team). The way I look at it, it also has to be a team thing and not an individual thing as the sitting around talking rubbish is a key part to the team being a team. Even if it is just over a cup of nasty coffee in the basement – that particular company’s canteen was not the best.

Oh, I should mention that I have access to a wife that makes wonderful cakes. Left-over cake is a brilliant “team ice-cream” substitute, it is both “cheap” so not a bribe but also appreciated as someone put effort in. My wife in this case. I Never claim I made the cake. well, not often.

TeddyBear Picnic Cake

That’s the carrot. What about the stick? When it comes down to it, you are there to guide the team and the individuals in it and get the best you can out of them. Not being disliked is important but you are not there to be their friend either. If someone transgresses you need to correct them.

In my opinion one of the very worst things a manager can do is dress down a member of their staff in public. That is not correcting them, that is either an attempt to humiliate them or an attempt by the boss to scape-goat the blame to a subordinate. Neither is morally correct and both are highly likely to engender considerable dislike or even hatred.

I distinctly remember one situation where I was in a team meeting and the boss’s managers came in and wanted to know why a recent change had gone so badly wrong. The manager’s response was immediate, he picked one of the team and said something like “It was him, he didn’t test the change properly”. It was so obvious that the sub-text was “it was not my fault”. In reality the sacrificed staff member was not at fault but the boss sure as heck was. A manager gets paid more as a boss and part of the reason is that you take both the credit and the blame for your team’s efforts. This action by that boss did not make us scared of failing and thus work harder, it made us distrust the man and demoralised us.

Sadly it is something I’ve seen a lot over the years and never by what I would call a good manager. I just don’t understand why these people think a public dressing down is going to inspire the target or the audience to work more effectively.

If I’m in the situation where, in a meeting or discussion, it becomes obvious one of my guys has screwed up we discuss how to sort it out as a team. Then after the meeting, the transgressor and I have a private conversation. This has several benefits:

  • I am not publicly humiliating them or scoring points in front of a crowd.
  • Neither of us is playing to the crowd and so are more likely to be honest.
  • Things can be said that stay private. I’ve had team members mess things up because they have more important issues on their mind that they are uncomfortable with the team knowing about. I’ve had to tell a guy this is chance #last and the next step is disciplinary.
  • This never happens, but there is a very small theoretical chance I could have misunderstood and, in fact, it’s my fault. You look a right idiot if you attempt to dress someone down in public and it turns out to be you.

As I said, that last point has never happened to me {yes, this is an outrageous lie :-) }. I’ve experienced that last point from the other side as well. In a large meeting I had a board member pushing me as to why we had not finished a project on the date I promised. I kept giving vague answers about “other things coming up” and it would be done by a new, given date. She would not let it go though so eventually I had to say “It is late because you told me to do other stuff as top priority, I raised this project and you told me to delay it. So it is late because you changed the priorities. That would make it your responsibility.” She was very angry but it had been her choice to do this publicly.

All this boils down to – Reward the team in public. Chastise the individual in private.

Friday Philosophy – Human Tuning Issues September 23, 2011

Posted by mwidlake in Friday Philosophy, humour, Perceptions, performance.
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6 comments

Oracle Tuning is all about technical stuff. It’s perhaps the most detail-focused and technical aspect of Oracle Administration there is. Explain Plans, Statistics, the CBO, database design, Physical implementation, the impact of initialisation variables, subquery factoring, sql profiles, pipeline functions,… To really get to grips with things you need to do some work with 10046 and 10053 traces, block dumps, looking at latching and queueing…

But I realised a good few years ago that there is another, very important aspect and one that is very often overlooked. People and their perception. The longer I am on an individual site, the more significant the People side of my role is likely to become.

Here is a little story for you. You’ll probably recognise it, it’s one that has been told (in many guises) before, by several people – it’s almost an IT Urban Myth.

When I was but a youth, not long out of college, I got a job with Oracle UK (who had a nice, blue logo back then) as a developer on a complex and large hospital system. We used Pyramid hardware if I remember correctly. When the servers were put in place, only half the memory boards and half the CPU boards were initiated. We went live with the system like that. Six months later, the users had seen the system was running quite a bit slower than before and started complaining. An engineer came in and initiated those other CPU boards and Memory boards. Things went faster and all the users were happy. OK, they did not throw a party but they stopped complaining. Some even smiled.

I told you that you would recognise the story. Of course, I’m now going to go on about the dishonest vendor and what was paid for this outrageous “tuning work”. But I’m not. This hobbling of the new system was done on purpose and it was done at the request of “us”, the application developers. Not the hardware supplier. It was done because some smart chap knew that as more people used the system and more parts of it were rolled out, things would slow down and people would complain. So some hardware was held in reserve so that the whole system could have a performance boost once workload had ramped up and people would be happy. Of course, the system was now only as fast as if it had been using all the hardware from day one – but the key difference was that rather than having unhappy users as things “were slower than 6 months ago”, everything was performing faster than it had done just a week or two ago, and users were happy due to the recent improvement in response time. Same end point from a performance perspective, much happy end point for the users.

Another aspect of this Human side of Tuning is unstable performance. People get really unhappy about varying response times. You get this sometimes with Parallel Query when you allow Oracle to reduce the number of parallel threads used depending on the workload on the server {there are other causes of the phenomena such as clashes with when stats are gathered or just random variation in data volumes}. So sometimes a report comes back in 30 minutes, sometimes it comes back in 2 hours. If you go from many parallel threads to single threaded execution it might be 4 hours. That really upsets people. In this situation you probably need to look at if you can fix the degree of parallelism that gives a response time that is good enough for business reasons and can always be achieved. OK, you might be able to get that report out quicker 2 days out of 5, but you won’t have a user who is happy on 3 days and ecstatic with joy on the 2 days the report is early. You will have a user who is really annoyed 3 days and grumbling about “what about yesterday!” on the other 2 days.

Of course this applies to screens as well. If humans are going to be using what I am tuning and would be aware of changes in performance (ie the total run time is above about 0.2 seconds) I try to aim for stable and good performance, not “outright fastest but might vary” performance. Because we are all basically grumpy creatures. We accept what we think cannot be changed but if we see something could be better, we want it!

People are happiest with consistency. So long as performance is good enough to satisfy the business requirements, generally speaking you just want to strive to maintain that level of performance. {There is one strong counter-argument in that ALL work on the system takes resource, so reducing a very common query or update by 75% frees up general resource to aid the whole system}.

One other aspect of Human Tuning I’ll mention is one that UI developers tend to be very attuned to. Users want to see something happening. Like a little icon or a message saying “processing” followed soon by another saying “verifying” or something like that. It does not matter what the messages are {though spinning hour glasses are no longer acceptable}, they just like to see that stuff is happening. So, if a screen can’t be made to come back in less than a small number of seconds, stick up a message or two as it progresses. Better still, give them some information up front whilst the system scrapes the rest together. It won’t be faster, it might even be slower over all, but if the users are happier, that is fine. Of course, Oracle CBO implements this sort of idea when you specify “first_n_rows” as the optimizer goal as opposed to “all_rows”. You want to get some data onto an interactive screen as soon as possible, for the users to look at, rather than aim for the fastest overall response time.

After all, the defining criteria of IT system success is that the users “are happy” -ie accept the system.

This has an interesting impact on my technical work as a tuning “expert”. I might not tune up a troublesome report or SQL statement as much as I possibly can. I had a recent example of this where I had to make some batch work run faster. I identified 3 or 4 things I could try and using 2 of them I got it to comfortably run in the window it had to run in {I’m being slightly inaccurate, it was now not the slowest step and upper management focused elsewhere}. There was a third step I was pretty sure would also help. It would have taken a little more testing and implementing and it was not needed right now. I documented it and let the client know about it, that there was more that could be got. But hold it in reserve because you have other things to do and, heck, it’s fast enough. {I should make it clear that the system as a whole was not stressed at all, so we did not need to reduce system load to aid all other things running}. In six months the step in the batch might not be fast enough or, more significantly, might once more be the slowest step and the target for a random management demand for improvement – in which case take the time to test and implement item 3. (For those curious people, it was to replace a single merge statement with an insert and an update, both of which could use different indexes).

I said it earlier. Often you do not want absolute performance. You want good-enough, stable performance. That makes people happy.

Friday Philosophy – Why doesn’t Agile work? September 16, 2011

Posted by mwidlake in development, Friday Philosophy, Management.
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Why doesn’t Agile Development Methodology seem to work?

I’m going say right here at the start that I like much of what is in Agile, for many, many years I’ve used aspects of Rapid Application Development {which Agile seems to have borrowed extensively from} to great success. However, after my post last week on database design, many of the comments were quite negative about Agile – and I had not even mentioned it in my post!

To nail my flag to the post though, I have not seen an Agile-managed project yet that gave me confidence that Agile itself was really helping to produce a better product, a product more quickly and most certainly not a final system that was going to be easy to maintain. Bring up the topic of Agile with other experienced IT people and I would estimate 90% of the feedback is negative.

That last point about ongoing maintenance of the system is the killer one for me. On the last few projects I have been on where the culture was Agile-fixated I just constantly had this little voice in my head going:

“How is anyone going to know why you did that in six months? You’ve just bolted that onto the side of the design like a kludge and it really is a kludge. When you just said in the standup meeting that we will address that issue ‘later’, is that the same “later” that accounts for the other half-dozen issues that seem to have been forgotten?”.

From what I can determine after the fact, that voice turns out to be reason screaming out against insanity. A major reason Agile fails is that it is implemented in a way that has no consideration for post-implementation.

Agile, as it is often implemented, is all about a headlong rush to get the job done super-quick. Ignore all distractions, work harder, be completely focused and be smarter. It really does seem to be the attitude by those who impose Agile that by being Agile your staff will magically come up with more innovative solutions and will adapt to any change in requirements just because they work under an agile methodology. Go Agile, increase their IQ by 10 points and their work capacity by 25%. Well, it doesn’t work like that. Some people can in fact think on their feet and pull solutions out of thin air, but they can do that irrespective of the methodology. People who are more completer-finishers, who need a while to change direction but boy do they produce good stuff, have you just demoralized and hamstrung them?Agile does not suit the way all people work and to succeed those people it does not suit need to be considered.

The other thing that seems to be a constant theme under Agile is utterly knackered {sorry, UK slang, knackered means tired, worn out and a bit broken} staff. Every scrum is a mad panic to shove it all out of the door and people stop doing other things to cope. Like helping outside the group or keeping an eye on that dodgy process they just adopted as it needed doing. Agile fails when it is used to beat up team. Also, I believe Agile fails when those ‘distractions’ are ignored by everyone and work that does not fall neatly into a scrum is not done.

I suppose it does not help that my role has usually been one that is more Production Support than development and Agile is incompatible with production support. Take the idea of the scrum, where you have x days to analyse, plan, design, unit test and integrate the 6 things you will do in this round. On average I only spend 50% of my time dealing with urgent production issues, so I get allocated several tasks. Guess what, if I end up spending 75% of my time that week on urgent production issues, and urgent production issues have to take priority, I can screw up the scrum all on my own. No, I can’t pass my tasks onto others in the team as (a) they are all fully assigned to their tasks and (b) passing over a task takes extra time. Agile fails when it is used for the wrong teams and work type.

I’ve come to the conclusion that on most projects Agile has some beneficial impact in getting tasks done, as it forces people to justify what they have done each and every day, encourages communication and gives the developers a reason to ignore anything else that could be distracting them as it is not in the scrum. Probably any methodology would help with all of that.

My final issue with Agile is the idiot fanatics. At one customer site I spent a while at, they had an Agile Coach come around to help the team to become more agile. I thought this was a little odd as this team was actually doing a reasonable job with Agile, they had increased productivity and had managed to avoid the worst of the potential negative impacts. This man came along and patronisingly told us we were doing OK, but it was hard for us to raise our game like this, we just needed help to see the core values of Agile and, once we did, once we really believed in it, productivity would go up 500% {That is a direct quote, he actually said “productivity will go up by 500%”}. He was sparkly-eyed and animated and full of the granite confidence of the seriously self-deluded. I think he managed to put back the benefits of Agile by 50%, such was the level of “inspiration” he gave us. Agile fails when it is implemented like a religion. It’s just a methodolgy guys.

I find it all quite depressing as I strongly suspect that, if you had a good team in a positive environment, doing a focused job, Agile could reap great rewards. I’m assured by some of my friends that this is the case. {update – it took my good friend Mike less than an hour to chime in with a comment. I think I hit a nerve}.

Friday Philosophy – The Dying Art of Database Design? September 9, 2011

Posted by mwidlake in Architecture, development, Friday Philosophy, rant.
Tags: , , ,
35 comments

How many people under the age of {Martin checks his age and takes a decade or so off} ohh, mid 30’s does any database design these days? You know, asks the business community what they want the system to do, how the information flows through their business, what information they need to report on. And then construct a logical model of that information? Judging by some of the comments I’ve had on my blog in the last couple of years and also the meandering diatribes of bitter, vitriolic complaints uttered by fellow old(er) hacks in the pub in the evening, it seems to be coming a very uncommon practice – and thus a rare and possibly dying skill.

{update – this topic has obviously been eating at my soul for many years. Andrew Clark and I had a discussion about it in 2008 and he posted a really good article on it and many, many good comments followed}

Everything seems to have turned into “Ready, Fire, Aim”. Ie, you get the guys doing the work in a room, develop some rough idea of what you want to develop (like, look at the system you are replacing), start knocking together the application and then {on more enlightened projects} ask the users what they think. The key points are the that development kicks off before you really know what you need to produce, there is no clear idea of how the stored data will be structured and you steer the ongoing development towards the final, undefined, target. I keep coming across applications where the screen layouts for the end users seem to almost be the design document and then someone comes up with the database – as the database is just this bucket to chuck the data into and scrape it out of again.

The functionality is the important thing, “we can get ‘someone’ to make the database run faster if and when we have a problem”.

Maybe I should not complain as sometimes I am that ‘someone’ making the database run faster. But I am complaining – I’m mad as hell and I ain’t gonna take it anymore! Oh, OK, in reality I’m mildly peeved and I’m going to let off steam about it. But it’s just wrong, it’s wasting people’s time and it results in poorer systems.

Now, if you have to develop a simple system with a couple of screens and a handful of reports, it might be a waste of time doing formal design. You and Dave can whack it together in a week or two, Chi will make the screens nice, it will be used by a handful of happy people and the job is done. It’s like building a wall around a flower bed. Go to the local builders merchants, get a pallet of bricks, some cement and sand (Ready), dig a bit of a trench where you want to start(Aim) and put the wall up, extending it as you see fit (Fire). This approach won’t work when you decide to build an office block and only a fool from the school of stupid would attempt it that way.

You see, as far as I am concerned, most IT systems are all about managing data. Think about it. You want to get your initial information (like the products you sell), present it to the users (those customers), get the new (orders) data, pass it to the next business process (warehouse team) and then mine the data for extra knowledge (sales patterns). It’s a hospital system? You want information about the patients, the staff, the beds and departments, tests that need doing, results, diagnoses, 15,000 reports for the regulators… It’s all moving data. Yes, a well design front end is important (sometimes very important) but the data is everything. If the database can’t represent the data you need, you are going to have to patch an alteration in. If you can’t get the data in quick enough or out quick enough, your screens and reports are not going to be any use. If you can’t link the data together as needed you may well not be able to DO your reports and screens. If the data is wrong (loses integrity) you will make mistakes. Faster CPUS are not going to help either, data at some point has to flow onto and off disks. Those slow spinning chunks of rust. CPUS have got faster and faster, rust-busting has not. So data flow is even more important than it was.

Also, once you have built your application on top of an inadequate database design, you not only have to redesign it, you have to:

  • do some quick, hacky  fixes to get by for now
  • migrate the existing data
  • transform some of it (do some data duplication or splitting maybe)
  • alter the application to cope
  • schedule all of the above to be done together
  • tie it in with the ongoing development of the system as hey, if you are not going to take time to design you are not going to take time to assess things before promising phase 2.

I’m utterly convinced, and experience backs this up, that when you take X weeks up front doing the database design, you save 5*X weeks later on in trying to rework the system, applying emergency hacks and having meetings about what went wrong. I know this is an idea out of the 80’s guys, but database design worked.

*sigh* I’m off to the pub for a pint and to reminisce about the good-old-days.

Friday Philosophy – Tainted by the Team August 26, 2011

Posted by mwidlake in development, Friday Philosophy, humour, Management, rant.
Tags: , , , ,
3 comments

A while ago whilst working on one project, a colleague came back to his desk next to mine and exclaimed “I hate working with that team! – they are so bad that it makes everyone who works with them look incompetent!”

Now there is often an argument to be made that working with people who are not good at their job can be great for you, as you always looks good in comparison {it’s like the old adage about hanging around with someone less attractive than you – but I’ve never found anyone I can do that with…}. It is to an extent true of course, and though it can seem a negative attitude, it is also an opportunity to teach these people and help them improve, so everyone potentially is a winner. I actually enjoy working with people who are clueless, so long as they will accept the clues. You leave them in a better state than when you joined them.

However, my friend was in the situation where the team he was dealing with was so lacking in the skills required that if you provided them with code that worked as specified, which passed back the values stated in the correct format derived from the database with the right logic… their application code would still fall over with exceptions – because it was written to a very, very “strict” interpretation of the spec.

In one example, the specification for a module included a “screen shot” showing 3 detail items being displayed for the parent object. So the application team had written code to accept only up to 3 detail items. Any more and it would crash. Not error, crash. The other part of the application, which the same people in the application team had also written, would let you create as many detail items for the parent as you liked. The data model stated there could be many more than 3 detail items. I suppose you could argue that the specification for the module failed to state “allow more than three items” – but there was a gap in the screen to allow more data, there was the data model and there was the wider concept of the application. In a second example, the same PL/SQL package was used to populate a screen in several modes. Depending on the mode, certain fields were populated or not. The application however would fail if the variables for these unused fields were null. Or it would fail if they were populated. The decision for each one depended on the day that bit of the module had been written, it would seem. *sigh*

The situation was made worse by the team manager being a skilled political animal, who would always try to shift any blame to any and all other teams as his first reaction. In the above examples he tried to immediately lay the blame with my colleague and then with the specification, but my colleague had managed to interpret the spec fine (he did the outrageous thing of asking questions if he was not sure or checked the data model). Further, this manager did not seem to like his people asking us questions, as he felt it would make it look like they did not know what they were doing. Oddly enough they did NOT know what they were doing. Anyway, as a consequence of the manager’s hostile attitude, the opportunity to actually teach the poor staff was strictly limited.

That was really the root of the problem, the manager. It was not the fault of the team members that they could not do the job – they had not had proper training, were unpracticed with the skills, siloed into their team, not encouraged to think beyond the single task in front of them and there was no one available to show them any better. The issue was that they were being made to do work they were not able to do. The problem, to my mind, was with the manager and with the culture of that part of the organisation that did not deal with that manager. He obviously did not believe that rule one of a good manager is to look after the best interests of your team. It was to protect his own backside.

But the bottom line was that this team was so bad that anything they were involved in was a disaster and no one wants to be part of a disaster. If you worked with them, you were part of the disaster. So we took the pragmatic approach. When they had the spec wrong, if we would alter our code to cope, we would alter our code. And document that. It gave us a lot of work and we ended up having a lot of “bugs” allocated to our team. But it got the app out almost on time. On-going maintencance could be a bit of an issue but we did what we could on our side to spell out the odditites.

I still know my friend from above and he still can’t talk about it in the pub without getting really quite agitated :-)

Friday Philosophy – Dyslexia Defence League August 19, 2011

Posted by mwidlake in Friday Philosophy, Perceptions, Private Life.
Tags: , ,
2 comments

NB This post has nothing to do with Oracle or even technology really. It’s just some thoughts about one aspect of my life.

I know I’ve mentioned this once before, though it was in an early blog post when I had a readership of about 8, but I am mildly dyslexic. If you want to know how I found out I was dyslexic then check out the original post. I’m quite fond of that post, as a non-technical one, though almost no one read it.

The thing is, I now cringe slightly when I say I am Dyslexic. I’ve sat on this post for weeks, wondering if I should post it. You see, it seems to me that dyslexia, along with some other oddities of perception, have over the last few years almost become a thing to be proud of. A banner to wave to show how great you are. “Hey, look at me, I am this good even though I have Dyslexia” or even “I am great because I have dyslexia”. Maybe I am just a little sensitive about it but it seems to me that more and more people make a thing about it. If I am being candid, I feel a little proud that I did OK academically despite it {I should point out there is no proven link between dyslexia and IQ but in exams you get marked down for spelling and slow reading speed means it takes longer to, well, read stuff!} and in the past I have been very open about mentioning it. Hey, this is my second blog on dyslexia!

However, I’ve had it suggested to me in the past that I use it as a defense for being lazy – Can I prove I am dyslexic? Does it really impact me that much? Well, actually no I cannot prove it and has it impacted me? Not a great deal I guess as I can read pretty much anything {I did say it was mild. Scientific papers and anything with very long words can be a challenge, but isn’t that true of everyone?}. My reading speed is about 120,150 words a minute. Average is about 250wpm. My wife seems to read at about 500wpm :-)

Also, don’t get me wrong, I fully appreciate that looking at a challenge you have and taking the benefits from it that you can is a very healthy attitude. If I remember right it was Oliver Sacks in one of his books (“the man who mistook his wife for a hat” maybe) who describes a man with sever Tourette’s syndrome {which is more often all about physical ticks and uncontrolled motions rather than the famous “swearing” aspect of it} who could somehow take advantage of his physical manifestations in his jazz drumming. He could just make it flow for him. But when he took treatment to control the physical issues, his jazz drumming suffered. He really wanted the benefit of the drugs for day-to-day life but keep the Tourettes for jazz. So he took the drugs during the week and came off just before the weekends when he played. Neat.

Does Dyslexia help me? I think I am more of a diagrams and pictures person than a text person because of my dyslexia and I think I maybe look at things a little differently to most people at times – because of the differences in how I perceive. That can help me see things that maybe others have missed? Maybe an advantage. I’ll take that.

Also, in my case at least, dyslexia is not an issue for me comprehending or constructing written prose. I think I write some good stuff at times.

But I don’t want to be dyslexic. Frankly, it p122es me off.

I’ll give you an example. I did a blog post a few weeks back and it had some script examples in it. I had nearly finished it when I realised I had constantly spelt one word utterly wrong. The spell checker picked it up. But just before I posted it, I realised I had also got my column aliases utterly wrong. I have a little set of rules for generating table and column aliases, it is not complex, but in my head the leading letters of a word are not always, well, the leading letters. I had to alter my scripts and then re-run them all as I knew if I tried to unpick the spelling mistakes manually I would mess it up, I’ve been there before. It took me hours. I can really do without wasting that time. {Update, since originally drafting this post the same situation with another technical post has occurred}. Then there is the embarrassment of doing something like spelling the name of a column wrong when you design and build a database. I did that in a V8 database when renaming columns was still not a simple task {was it really Oracle 9 release 2 before column rename was introduced?}. The database went live and accrued a lot of data before anyone made an issue of it. It then kept getting mentioned and I had to keep explaining.

I don’t see Dyslexia as a badge of honour and every time I see someone being proud of it (or to my odd mind it seems they are proud of it) or suggesting they are better than average for overcoming it (again, maybe it is just my perception), I just feel uncomfortable. I think all and everyone of us has something we have had to overcome to be “normal”.

Yet, on reading that above paragraph back, it is simply insulting to people who have fought and striven to overcome severe dyslexia or other issues with perception or communication. I certainly do not mean that (and I apologise unreservedly to anyone who is now fuming at me because of my callousness).

Maybe that is my issue with the whole topic – I am not uncomfortable with the notion of being proud to have overcome something like dyslexia and I admire people who cope with other conditions which make it harder for them to get by in our culture, but I just can’t see why you would be proud of the condition or want to use it as a bragging right.

I guess I want to be able to just acknowledge my dyslexia, point out it is no big deal in my case but it is why I spell like a 10 year old. It is as significant as the fact I’m scared of heights. I guess I cringe a little when I say it as I don’t want to be seen to be making excuses and I certainly do not feel, that in my case at least. I have won through against the odds. Maybe I’ve been a little hard-done-by occasionally but haven’t we all?

Friday Philosophy – Blogging Style and Aim August 12, 2011

Posted by mwidlake in Blogging, Friday Philosophy.
Tags: , ,
13 comments

I’ve recently looked back at some of my earlier blog postings and also some notes I made at the time I started. I had a few aims at the start, pretty much in this order:

  • A place to put all those Oracle thoughts and ideas, for my own benefit
  • Somewhere to record stuff that I keep forgetting
  • I’d started commenting on other blogs and felt I was maybe too verbal on them
  • To increase my profile within the Oracle community
  • To share information, because I’m quite socialist in that respect
  • To learn more

It very quickly morphed into something slightly different though.

Firstly, it is not really somewhere that I record thoughts and ideas or where I record stuff that I forget. When I am busy, I sometimes only get half way to the bottom of resolving an issue or understanding some feature of Oracle. I tend to create little documents about them but I can lose track of them. I initially intended to put these on my blog. The thing is though, I don’t feel I can blog about them because I might be wrong or I raise more questions than I answer. I don’t think a public blog about technology is a good place to have half-baked ideas and I certainly don’t want people:

  1. reading and believing something that is wrong
  2. thinking I do not know what I am talking about
  3. seeing my rough notes as boy are they rough, often with naughty words in them and slang. Converting them to a familly-friendly format takes time. 

You see, there is the point about increasing my profile in the community. Part of me hates the conceit that you have to be seen as all-knowing or never wrong, as no one is all-knowing and never wrong. In fact, I think most of us find it hard to like people who put themselves as such.  But if I put out a blog saying “it works this way” and I am wrong or I simply say it in a clumsy way or I assume some vital prior knowledge, I could be making people’s lives harder not easier, so I spend a lot of effort testing and checking. It takes me a lot, lot longer to prepare a technical blog than I ever thought it would before I started. And yes, I accept I will still get it wrong sometimes.

Another consideration is that I make my living out of knowing a lot about Oracle. If I post a load of blogs saying something like “gosh I wish I understood how Oracle locks parts of the segment as it does an online table rebuild and handles the updates that happen during it”, then I obviously don’t know about that. Or I put out a post about how I currently think it works and I’m wrong. Tsch, I can’t be that good! How much should I have to think about how I am selling myself as a consultant? There is a difference between being liked and being perceived as good at what you do. If you want someone to design a VLDB for you, you probably don’t care if s/he is a nice person to spend an evening in the pub with – but you certainly care if they seem to be fundamentally wrong about oracle partitioning.

Balancing that, if you saw my recent post on Pickler Fetch you will see that I was wrong about a couple of things and there was some stuff I did not know yet. But I learnt about those wrong things and lack of knowledge, so I feel good about that. That was one of my original aims, to learn. Not only by having to check what I did but by people letting me know when I was wrong.

What about style? I can be quite flippant and, oh boy, can I go on and on. I know some people do not like this and, if you want a quick solution to an oracle problem, you probably do not want to wade through a load of side issues and little comments. You just want to see the commands, the syntax and how it works. Well, that is what the manuals are for and there a lot of very good web sites out there that are more like that. If you do not like my verbose style then, hey that’s absolutely fine.  But I like to write that way and so I shall.

So after over 2 years of blogging, I seem to have settled into a style and my aims have changed.

  • I try to be helpful and cover things in detail.
  • I try to polish what I present a lot, lot more than I do for my own internal notes. Maybe too much.
  • I’m going to write in a long-winded way that some people will not enjoy but it is my style.
  • I’m going to try and worry less about looking perfect as I am not.

I suppose what I could do is start a second, private blog with my half-baked stuff on it. But I just don’t think I’ve got the time :-)

 

 

 

 

Friday Philosophy – Oracle Performance Silver Bullet August 5, 2011

Posted by mwidlake in Architecture, Friday Philosophy, performance.
Tags: , , ,
15 comments

Silver Cartridge and Bullet

For as long as I have been working with Oracle technology {which is now getting towards 2 decades and isn’t that pause for thought} there has been a constant search for Performance Silver Bullets – some trick or change or special init.ora parameter {alter system set go_faster_flag=’Y’} you can set to give you a guaranteed boost in performance. For all that time there has been only one.

There are a few performance Bronze Bullets…maybe Copper Bullets. The problem is, though, that the Oracle database is a complex piece of software and what is good for one situation is terrible for another. Often this is not even a case of “good 90% of the time, indifferent 9% of the time and tragic 1% of the time”. Usually it is more like 50%:30%:20%.

Cartridge with copper bullet &spent round

I’ve just been unfair to Oracle software actually, a lot of the problem is not with the complexity of Oracle, it is with the complexity of what you are doing with Oracle. There are the two extremes of OnLine Transaction Processing (lots of short running, concurrent, simple transactions you want to run very quickly by many users) and Data Warehouse where you want to process a vast amount of data by only a small number of users. You may well want to set certain initialisation parameters to favour quick response time (OLTP) or fastest processing time to completion (DW). Favouring one usually means a negative impact on the other. Many systems have both requirements in one… In between that there are the dozens and dozens of special cases and extremes that I have seen and I am just one guy. People get their database applications to do some weird stuff.

Partitioning is a bronze bullet. For many systems, partitioning the biggest tables makes them easier to manage, allows some queries to run faster and aids parallel activity. But sometimes (more often than you might think) Partitioning can drop rather than increase query or DML performance. In earlier versions of Oracle setting optimizer_index_caching and optimizer_index_cost_adj was often beneficial and in Oracle 9/8/7 setting db_file_multiblock_read_count “higher” was good for DWs….Go back to Oracle 7 and doing stuff to increase the buffer cache hit ratio towards 98% was generally good {and I will not respond to any comments citing Connors magnificent “choose your BCHR and I’ll achieve it” script}.
You know what? There was an old trick in Oracle 7 you could maybe still look at as a bronze bullet. Put your online redo logs and key index tablespaces on the fastest storage you have and split your indexes/tables/partitions across the faster/slower storage as is fit. Is all your storage the same speed? Go buy some SSD and now it isn’t….

Cartridge with Wooden Bullet

Then there are bronze bullets that you can use that very often improve performance but the impact can be catastrophic {Let’s call them wooden bullets :-) }. Like running your database in noarchivelog mode. That can speed up a lot of things, but if you find yourself in the situation of needing to do a recovery and you last cold backup is not recent enough – catastrophe. A less serious but more common version of this is doing things nologging. “oh, we can just re-do that after a recovery”. Have you done a test recovery that involved that “oh, we can just do it” step? And will you remember it when you have a real recovery situation and the pressure is on? Once you have one of these steps, you often end up with many of them. Will you remember them all?

How many of you have looked at ALTER SYSTEM SET COMMIT_WRITE=’BATCH,NOWAIT’? It could speed up response times and general performance on your busy OLTP system. And go lose you data on crash recovery. Don’t even think about using this one unless you have read up on the feature, tested it, tested it again and then sat and worried about could possibly go wrong for a good while.

That last point is maybe at the core of all these Performance Bronze Bullets. Each of these things may or may not work but you have to understand why and you have to understand what the payback is. What could now take longer or what functionality have I now lost? {hint, it is often recovery or scalability}.

So, what was that one Silver Bullet I tantalizingly left hanging out for all you people to wait for? You are not going to like this…

Look at what your application is doing and look at the very best that your hardware can do. Do you want 10,000 IOPS a second and your storage consists of less than 56 spindles? Forget it, your hardware cannot do it. No matter what you tune or tweak or fiddle with. The one and only Performance Silver Bullet is to look at your system and your hardware configuration and work out what is being asked and what can possibly be delivered. Now you can look at:

  • What is being asked of it. Do you need to do all of that (and that might involve turning some functionality off, if it is a massive drain and does very little to support your business).
  • Are you doing stuff that really is not needed, like management reports that no one has looked at in the last 12 months?
  • Is your system doing a heck of a lot to achieve a remarkably small amount? Like several hundred buffer gets for a single indexed row? That could be a failure to do partition exclusion.
  • Could you do something with physical data positioning to speed things up, like my current blogging obsession with IOTs?
  • You can also look at what part of your hardware is slowing things down. Usually it is spindle count/RAID level, ie something dropping your IOPS. Ignore all sales blurb from vendors and do some real-world tests that match what you app is or wants to do.

It’s hard work but it is possibly the only Silver Bullet out there. Time to roll up our sleeves and get cracking…

{Many Thanks to Kevin Closson for providing all the pictures – except the Silver Bullet, which he only went and identified in his comment!}

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