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Data Dictionary Performance – reference September 29, 2009

Posted by mwidlake in internals, Perceptions.
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1 comment so far

I’ve got a couple more postings on Data Dictionary performance to get where I plan to go to with this, but if you want to deep-dive into far more technical details then go and check out Dion Cho’s excellent posting on fixed object indexes.

I was not planning on getting into the sys.x$ fixed objects as you need SYS access to look at them, which not everyone has, but this is where Dion goes. His posts are always good, I need to check them far more.

As a soft-technical aside, I often mention to people when doing courses on SQL or writing standards or even the odd occasions I’ve discussed perception, that we Westerners are taught to read from left to right, top-to-bottom and we pick out left justification very well. Code laid out like the below we find easy to read:

select pers.name1                surname
      ,pers.name2                first_forename
      ,pers.nameother            middle_names
      ,peap.appdate              appointment_date
      ,decode (addr.name_num_ind
                 ,'N', to_char(addr.housenum)
                 ,'V', addr.housename
                 ,'B', to_char(addr.housenum
                              ||' '||addr.housename)
                                 house_no_name
      ,addr.address2             addr_street
      ,addr.address3             addr_town
      ,addr.address4             addr_dist
      ,addr.code                 addr_code
from person              pers
     ,address            addr
    ,person_appointments peap
where pers.addr_id     =addr.addr_uid
and   pers.pers_id     =peap.pers_id
and   pers.active_fl   ='Y'
and   pers.prim_cons   ='ANDREWSDP'
and   peap.latest_fl   ='Y'

But this is not true of other cultures, where people do not read left to right, top to bottom. I have had this confirmed just a couple of times when people who were born in Eastern cultures are in the course/conversation.

So I was very interested to see Dion’s Korean version of the blogpost I reference above (I really hope this link here to the korean version is stable).
The main body of the page is on the right, not left, but the text appears to be left justified.

Of course, I am horribly ignorant, I do not know which direction Koreans read in :-(. I could be spouting utter rubbish.

Friday Philosophy – Who Comes Looking? September 18, 2009

Posted by mwidlake in Blogging.
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8 comments

I’ve been running this blog for a few months now and I find it interesting to see how people come to it. A handful of people come to it as I tell them I have a blog page, but most people come across it by either:

  • Links from other blogs or web pages.
  • Search engines.

WordPress gives me stats on these for Today and Yesterday and I can check back on the referrers and searches for any given day, going back several months. Most blog sites provide the same features, I thought I would just run through them for those who do not have a blog.

I can tell when I have been mentioned on someone else’s blog, as I usually see a spike in my hits and their web page is at or near the top of the list of referrers. Interestingly, I will sometimes see a burst of hits from an old reference on someone else’s blog or webpage. I think this happens when a third person has referenced the page or person which then referenced me.

Another interesting facet is the impact on my hits if an Oracle Name mentions me. My busiest day occurred when Richard Foote mentioned a posting I did on “Unhelpful Helpful People” and a couple of other well-known Oracle Names also picked up on the thread. It’s a bit like a small-time-actor getting into a scene with a Hollywood Star :-).

The most interesting, though, are the search engine hits.

My favorite search term to lead to my blog so far is “martin widlake unhelpful people”. I really hope that was someone looking for the post I mention above, as opposed to anything else…

As time goes by, the search engine hits are generating a larger and larger slice of my traffic (and the personal mentions less and less :-) ). This is going to be partly due to me putting more content on the Blog to be found but also, as I get more hits and links, search engines will give me more prominence. It becomes self-feeding. Search engines find me as I have been visited before, so I get visited again and Search engines see that I have been visited even more and move me up the list…

{This is, of course, how Burleson gets so much traffic, he always references back to himself and his web sites and appears to have several sites that all cross-reference between them, priming the search engine pump (or absolutely flooding it, I suspect)}.

Some of the most common searches that find me are on obscure items I have blogged about. They may not be of such general interest {such as when I blogged about errors with gathering system statistics {{and more to follow on that topic}} } but I guess when someone hits the same issue or topic, I am one of a very few places that has mentioned it. I get a steady trickle of hits for “c_obj#_intcol#” since I blogged about it often being the biggest object in the SYSTEM tablespace. So perhaps to increase my search engine hits I should not blog about mainstream issues but rather really obscure, odd stuff than almost no one is interested in!

Some days I will get several hits by people searching on “Martin Widlake”. I wonder why they are searching on me specifically. Occasionally, it has been just before I am called about a job. Usually not though {so maybe it was about a job – but then they found my blog and decided against it…}.

Some searches that get to my blog are just odd. Yesterday one search that found me was “how to put fingers on keyboard”. Why? I have no idea why a search on that would land on my blog. Maybe I should try it!

Oh, and I suddenly have a favorite search that found me, hot in today, just as I am blogging about the very topic:

“it’s a crock of cr4p and it stinks”

Now what is that about? Why search on it and why find me?

*sigh*

Friday Philosophy – When the Job Meets Real Life August 15, 2009

Posted by mwidlake in Private Life.
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1 comment so far

For my Friday Philosophy this week, I’m going way off topic. I’m straying into non-work life. Actually, let’s be accurate, I’m wading deep into personal life. If you want to know about Oracle mechanics, this ain’t the post for you.

It’s been a trying week this week, so much so that I have not posted for a few days – and I suspect I won’t post at all next week. About two hours after completing my last post on Tuesday, my wife called me to let me know my mum had been taken into hospital. My mother had developed some breathing difficulties, in that she’d forgotten completely how to do it.

So, after tube/train/drive across the country I found myself sat in an intensive care unit with my Brother, wondering how in heck so many tubes can be attached to such a small person as my mother, but they managed it. All of this medical monitoring stuff is attached to computers, many with readouts.

I have a couple of advantages over most people in these situations. I studied biology at University and I worked either within or along side the NHS for 7 or 8 years, on hospital patient systems. So I understand a bit about all the equipment that is used and the data it produces.

What has this to do with the world of Oracle Performance? Not an awful lot. Except for one thing.

Sometimes, though I love what I do for a living and find solving performance problems stimulating and satisfying, I question “what is the point” in the whole real-world situation. I was sat there at the side of my mother’s bed, exchanging idle chat and some black humour with my brother {it’s the way our brains are wired, I blame my Mum}. Suddenly I stopped listening to my brother. The pattern had changed. The graphs had shifted and the figures had altered on the screens attached to the equipment monitoring my mother. I’d picked this up as I was used to watching performance graphs for computer systems. My brother was oblivious. Well what a surprise, an IT skill that turns out to be useful in the real world. Spotting graph/pattern changes.

As it turns out, the nursing staff had spotted these anomolous graphs too, glanced over, and realised it was just “one of those things”. Status quo was restored about 1 minute and 3 pints of my sweat later.

So why do I think my ability to spot a change in “performance graphs” and scare myself so deeply is a good thing? Because at least I had a feel for what was going on and I felt less clueless and helpless.

I’ve looke back on this and come to an even more shocking thought. There is a management technique that helps in real life. I have been a manager and I was surrounded by experts in their field. I was sat in a real-world situation, surrounded by experts in their field. When they did not react to the changed pattern on my mother’s monitors, I was reassured that it was not serious. So maybe some management skills have other uses too. I’ll remember that the next time someone tells me all management skills are bunkum. {But it probably still holds that most Managers are Bunkum :-) }

I wish that more IT managers could treat their staff this way. If the DBA team
{or Sys admin team, or network team} do not respond to the graphs as a sign of impending doom, then it probably ain’t impending doom, so trust them.

And of course the other reason I’ve blogged about this is it’s an outlet to a certain amount of trepidation about the future. Maybe I should have stuck to Biology rather than IT. *sigh*.

COC – The Chain of Optimistic Communication July 1, 2009

Posted by mwidlake in Management, Perceptions.
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3 comments

Well, after the very long, technology-based post of yesterday, a smaller one today, on a management theme.

I came up with this concept of the Chain of Optimistic Communication about a year ago, in one of my presentations on disasters. As a potential disaster, I’ve converted the relevant PowerPoint slides into a Flash movie. This is the flash movie. The second slide is an animation of what the Chain of Optimistic Communication is, the rest is some thoughts on it’s impact and how to avoid it.

{If the flash movie fails and you can read PowerPoints, you can download the
PowerPoint here}

{And another thing, It’s my first Flash attempt, I know the page numbering is duff, I know the layout is a little off, I might fix it when I have had some more sleep}.

If you can’t be bothered with the Flash movie {go on, it’s more fun than reading stuff!}, this is what the Chain of Optimistic Communication is:

  • You, the worker at the coal face are asked by your boss how the development of the new system is going. You tell your boss that it’s not going well at all and you list 3 things that have not been done, one that has been done and one that is partially done. You don’t mention that the partially done one you plan to do tonight, fuelled by coffee and whisky.
  • Your boss tells their boss that progress is being made, half the tasks are in hand but they “need to proactively re-address a resource mismatch or two”.
  • This top level boss tells the VP of development that all is in hand, resources are in place and all bases are covered, but more budget for planning would be wise. 
  • VP of Development reports to the board that the latest Agile development using cross-skilled resource pools is on track to deliver the milestone implementation. Or something.

ie all levels lie, ever so slightly optimistically as they communicate up the management chain.

As a result, the higher the manager, the more rosy the picture and the more out of touch they seem to the worker at the coal face.

When I presented this idea, I got a surprisingly positive response from the audience. It was the most common thing people talked to me about after the presentation, so I guess it struck a chord. Or else it was the point in the presentation when the sound of the caterers dropping a try outside woke them up.

Another side of the Chain of Optimistic Communication is that the higher the manger, the more they are led to believe all is OK and the more often, it seems to them, that apparently “under control” projects flip to become disasters when the rosy white lies have to be ditched when the reality becomes so grim. Often with no warning. No wonder managers get so many heart attacks and strokes.

 

{This is me just trying to get the flash movie to play with my website headers, it will disappear in a couple of hours flash movie}

The Sneaky WHAT Strategy!? June 15, 2009

Posted by mwidlake in biology, Perceptions.
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OK, I can’t resist any more, I have to write a Blog about this. I apologise up front for any offence I cause anyone, it is not intended.

There has been a bit of a thread between my and Richard Foote’s blog about the Dunning-Kruger effect. This is his post on it. The Dunning Kruger effect (Jonathan Lewis told us what it was called) is where people have an over-inflated opinion of their own ability. Since the names of behavioral traits came up, I have been unable to get something out of my mind.

When I was at college I studied Zoology. In one lecture on animal behaviour we were told about the “Sneaky Fuck3r Strategy”. Yes, you read it right, that is what it is called. {I’ve stuck a ‘3’ in there as I’m concerned I’ll blow up some web filters}.

It was described in the context of Red Deer. A single dominant male has a harem of females during the breeding season. Other big, strong males will challenge the Dominant Stag and, if they win, will take over the harem. So, this one Stag has all the lady deer at his disposal, only challenged by similarly large, aggressive males.

Well, not quite. What sometimes happens is that, when the dominant stag is fighting off a challenge, one of the younger stags will sneak into the herd and mate with one of the females. Thus the term “Sneaky Fuck3r strategy”. Genetic testing shows that quite a few of the deer born are not fathered by the dominant male!

The one little twist added during my lecture was that it had been observed that one young male, male(A), would go and challenge the dominant stag whilst another young male(B) snuck into the herd. Then, a while later Male(B) would challenge the stag and Male(A) would have his turn. I don’t know if that was an unsubstantiated embellishment but is suggests smart as well as sneaky.

I really thought she was pulling our legs about the name, but the lecturer wasn’t. It is a real term, used by real zoologists, though mostly UK-based. You can google it but I won’t blame you if you want to wait until you are not at work to do so!

Many people lay the credit for the name to John Maynard Smith But this article with Tim Clutton-Brockhas an excellent description of the situation {click on “show Transcript” and I suggest you search for the word “sneaky”}. I am not clear if Tim did the original work on the subject though. For some reason I can’t fathom, wikipedia does not mention the strategy in it’s entries for either scientist…

Hey, it’s not my fault I can’t spell. June 10, 2009

Posted by mwidlake in humour, Perceptions, Private Life.
Tags: , ,
1 comment so far

*Sigh*
I just got pinged by someone to let me know of some spelling mistakes in my blog. I know, I know, just leave me alone OK?!

Do you remember doing the “colour blind” test at school? {And, for our American cousins, “color blind”}. You know, you are shown a few images made up of dots, with numbers in them.

Most of the colour blindness images are far less obvious than this

Well, most people are shown 5 or 6 images and shout out “8”, “16” etc promptly five times and are then shown out – nothing more is said. Some people cry “7”, “34”, “dunno, give me a clue” and after 10 or 12 images get told they can’t distinguish blue & green or red & brown or something and so can’t drive trains or fly fighter planes… Me? I was in there for 5 minutes, coming up with what must have been very confusing answers. They even started showing me the same images again and I remember occasionally going something like “it’s 16 not 6, isn’t it”. Eventually they told me my colour vision was fine and threw me out as a time-waster. I wonder if I can fly fighter planes?

What they should probably have spotted (and a school teacher friend of mine got quite angry about this when I told her this story, as she thought they should have spotted this even back in the late 70’s) was that I could not read for toffee – as I have mild dyslexia. She had been taught how to identify dyslexia in children and one of the easiest ways was, she said, issues with the colour blindness test but without being colour blind.

When I read things I don’t do what a lot of people do, which is kind of pick up the start and end of long words and “see” it. I do it in little spirals. I do not know that I can explain better than that, but if I hit a long word (more than six letters) I start at the begining, flick to the back of the word and work back and if the two don’t meet I spiral in. I wonder if there is a cunning lexical trick I can sell to Oracle Text on that one?

It’s no where near as bad as many, heck I’ve managed to get by OK with it, but spell checkers have been a boon to me. The problem is, I don’t always remember to use them and, even if I do, a word spelt wrongly but is itself a correct word will not be picked up. I know, many packages now also have Grammer Checkers that could pick some of it up, but I find Grammer Checkers so infuriatingly useless, I turn them off.

So, sometimes my spelling is terrible. It’s because I have an IQ of 73, OK? The thing is, I probably got pinged in every exam I took because of it {except Maths, where in all honesty I got past the exams at age 16 and then it all stopped being logical. Sorry Mr Winters, I did my best as you know, but my brain could not do all that more advanced stuff}. I even got bollocked told off during my degree for carpals and carpels but heck, to me both read crapals.

I had particular fun a few years back when I introduced Oracle Partitioning to British Gas. No one had used it before but I had a quiet little application that I was passing over to the production DBAs to look after that did. So, I went over to Hinckley (oooh, thats a doozer to spell) where all the proddy DBAs lived and gave a presentation on Partitioning. Except I was doing it with white boards and OHP and every time I spelt Partitioning I wrote “rtit”, then went back and put in the “Pa” at the start and then tried to finish it off. Usually I managed. That was what prompted the chat with the teacher, I was telling her how that sort of thing happens to me and it’s annoying and she asked about if I had ever been tested for colour blindness.

So, there you go. It’s my excuse. Now you know that either I am right, or I have munchausens syndrome {just look it up, OK? Try this here}.

The odd thing? I can’t always spell “who” but I never get “Dyslexia” wrong.

The Knowledge Curtain. June 8, 2009

Posted by mwidlake in development, Management, Perceptions.
Tags: , , ,
5 comments

I came across the concept of “The Knowledge Curtain” in the late 90’s, from a man called Lee Young, who I worked with for 2 or 3 years, along with a friend Mike Cox, who was key to showing me how to peek through the curtain.

The below is taken from a powerpoint presentation I sometimes give on project disasters (how to avoid, not how to encounter!):

When systems designers talk to end users, both parties usually end up not really understanding each other

When systems designers talk to end users, both parties usually end up not really understanding each other

The basic principle is that, the knowledge of your users/customers is partly hidden from you. When you ask people for whom you are designing a computer system about their job, they don’t tell you lots of stuff.

  • Things that they assume you know.
  • Things that it does not occur to them to mention.
  • Things that they do not want to admit to doing as it sounds silly or badly managed.
  • I’ve even had people not mention parts of their job as they don’t want their manager knowing they do it.

But that is OK, when you talk about information technology and computer systems to them, they have exactly the same problems with what you say :-).

Lee’s presentation, with N. Mehandjiev, predated the all-encompasing rise of the internet and this is one of the few references to it I can find. {Among the relatively few other hits on the topic, amongst the ones about knowing how to make curtains, are references to the “Knowledge Curtain” as the concept that the Web is not as available in other areas of the world. A related but very different issue}.

So, how do you peak beyond the knowledge curtain? Systems designers and developers with experience learn how to ask the questions “what are the exceptions to what  you have just told me” and “what else do you do” in many, many ways and without giving offence. After all, you have to keep asking these two questions and people naturally get irritated with that and some feel you are suggesting they are either stupid or lying. It can be tricky. 

I think that unless you have someone who is fully IT literate and has done the job the computer system is to assist with, you will inevitably only catch a part of the requirements.

For massive projects over many months or years, I think this lack of a clear understanding of what people do is a major factor to their failures. This is made even worse when the analysis is done by one group of people and the specifications are then shipped out to an external party for the application to be developed. With all that missing knowledge, it is no wonder some systems are initially so poor.

I only know of one method that reliably allows you really see beyond the knowledge curtain. That is prototyping and user feedback. Only when you show the people who are going to use the system what you have put together to help them will they know if it works. These sessions are incredibly valuable and only in development projects where they have been key to process have I seen the project deliver something truely useful.

I now have a general way of developing anything.

  • I ask the users for 3 or 4 major things that they want the system to do.
  • I develop those 3 or 4 features as quickly as possible and show them to the users.
    • One will be almost exactly what they need.
    • One or two will be close to what they need.
    • One will be utterly useless.
    • During the above, one or two critical new needs will come up.
  • Fix the close ones, dump or redo the useless one and add the new needs to the list.

Simply cycle around the above, asking for new features when you have got less than 4 features you  are actively working on. And only polish features (add all the nice screen touches and widgets) once is is exactly what they need or pretty damned close. {You hardly ever run out of features before you run out of time and money!} You end up with an excellent system that evolves to better help the customer as time goes on.

There are lots of development methodologies that have the above principle (or a variation of it) as their core, so I am certainly not the first person to find that this method works. Which is why I find it difficult to understand why so many projects don’t use it?

BTW, I thought I would just add that one of the factors in my starting a blog was a comment by Andrew Clarke on his, several years ago before Blogging really took off. It was for a presentation I did which included the Knoweldge Curtain concept. He was very nice about my presentation and I still appreciate it. This is the link, but as it is an archive you will have to search for my name.

Fear of Databases May 29, 2009

Posted by mwidlake in Management, Perceptions.
Tags: , ,
4 comments

“It’s all in the database!”

I’m sure most of you (if you are in the UK, I must remember that the web is a world spanning medium) have seen the adverts by the wonderful TV Licencing authority or the DVLA. If not they go something like:

“We keep records” {background music}
“We know if you have paid…or not.” {Music become more sinister}
We will find you, you cannot hide” {more affirmative music}
“It’s all in the database” {doom-laden musical flourish}

OK, maybe I lay it on a bit with the music.

Now, as a database professional, I see “it’s all in the database” as a good thing. With luck it will be a well designed database with referrential integrity and all nicely validated.

Nearly all news media stories about actual or perceived threats to electronic privacy also site “The Database” as the core.
“They {who?} will hold all your web searches in a vast Database”.
” A laptop holding a Database of 1 million double glazing customers has been stolen”. I bet it was actually 10 thousand and in a spreadsheet.

It’s getting to the point where I don’t feel comfortable telling people I meet outside of the IT world that I am a database expert. Databases are hardly ever now seen in a good light, they seem to be linked only to things bad and Orwellian.

The Database is also often cited when companies get things wrong for their customers. You ring up to complain about some aspect of non-service and are often told “Oh, it doesn’t agree with you in the Database” or “the Database has got it wrong”. No it hasn’t, the person putting the information in the database got it wrong. I’ve been in the unusual situation of being told a lie where the database was given as the cause but I had access to that database. So I checked and the database was fine. It was being used as a convenient and much maligned excuse.

Very little is mentioned of the beneficial uses of databases.
For most of us our salary is processed via databases and it is a lot cheaper and more reliable than having half a hundred pay clerks doing it manually in pen and ink.
Databases are used to hold or index much of that vast quantity of stuff that you can search for on the net. Even the useful stuff on Klingons.
I for one would welcome a UK-wide database holding my basic medical details so that when I go to my GP or hospital, they do not need my memory (and in fact my consciousness) to tell them my medical past. If I have an allergy to a common drug I damned well want all medical people to know that before they put 10cc of the stuff into my veins.

And to wrap up my bad-tempered tirad, I now find it particularly tricky to talk about what I still feel is my most significant achievement in IT, namely an 80TB Database of genetic information. Without getting into the topic of Bioethics, which is beyond the scope of this blog, Genetics and a lot of biological stuff is now painted grey, if not deep, murkey, scary Red by the media. I tell John down the pub that I created a huge genetics database, he is sure I am either working on a secret government project to know all about his inner workings or some evil company combining tomatoes and monkeys into some awful, new thing that {and he has seen the movies to prove this} in all likelihood will turn into a zombie killer, escape and do for mankind.

Maybe I’ll just tell people I shoplift for a living, it might be more socially acceptable than being involved in Databases or Genetics.

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