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Friday Philosophy – The Tech to Do What You Need Probably Exists Already November 30, 2012

Posted by mwidlake in Friday Philosophy, Perceptions.
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4 comments

How many of you have read the Oracle Concepts manual for the main version you are working on?

This is a question I ask quite often when I present and over the last 10 years the percentage number of hands raised has dropped. It was always less than 50%, it’s been dropping to more like 1 in 10 and Last year (at the UKOUG 2011 conference) was the nadir when not a single hand was raised. {Interestingly I asked this at the Slovenian User Group 3 months ago and something like 40% raised their hand – impressive!}.

Why do I feel this is important? Well, do you know all the technology solutions available across just the core RDBMS with no cost options?. No, you don’t, you (and I) really don’t. If you read the concepts manual, even just skimming it, you will be reminded of a whole load of stuff you have only dim memories of and perhaps you will even see some features that passed you by when they were first introduced.

Of course, you would need to read a few more manuals to get the full picture, such as the PL/SQL Packages and Types References, as so much good stuff is introduced via built-in packages, and the SQL Language Reference, as SQL has been extended quite a lot over the last couple of versions. Dull reading indeed but I’d estimate that if you read those three you would be aware of 90%+ of the Oracle technologies that are available to you out-of-the-box and considerably more than all but a handful of Oracle Experts. You’d know more than I as (a) I have not skimmed the PL/SQL one for years and (b) I have a rotten memory.

My point it, you can’t consider using Oracle technologies you don’t know about or remember – and they could be just what you need to fix the problem you see in front of you.

I’ll give a couple of examples.

Problem, physical IO is too high, your storage system is bottle-necked.
Answers, Reducing Physical IO:
-First up, Index Organized tables. Some of you will be aware that I am very keen on IOTs and the reason I am is that I’ve used them to physically group data that the application needed to select over and over again. It can make a massive improvement to that sort of system. They are rarely used.
-Clustered Tables. Even less used, in fact has anyone reading this used them in anger in the last 10 years? Great for situations where you need parent-children or parent-children-type-1+parent-children-type-2 data. I confess, I have not used them in anger for years.
-Move table (and order them as you do it!) and re-build indexes to remove “dead” space. This one got a bad name, especially the index rebuilds, as people were doing it needlessly without appreciating what the intention was, but now I hardly ever see it done – even when it is of benefit.
-Compress your tables and indexes. With normal Oracle compress (no need for HCC). In tests I’ve done I pretty much always see a drop in physical IO and run time. Being candid, I can’t remember doing any tests and NOT seeing an improvement but I usually only test when I expect and improvement and I don’t want to give anyone the impression it will always help.

All the above were available in Oracle 7 or 8 and all have improved over the versions.

Problem, you want to carry out some long,complex data processing in PL/SQL and if a step fails, be able to handle it and carry on.
Answers:
– Savepoints. You can rollback to a savepoint, not just to the last commit. In this way you can break the task into chunks and, if something towards the end fails, you roll back one step (or several, your choice) and call an alternative routine to handle the exception.
– Autonomous Transactions. You want to record that an error occurred but not fail the original action or not save anything it has done to date. An autonomous transaction runs in it’s own sub-session and commits in it do not effect the calling session.
– Temporary Tables. You can put your working information in them as you progress and if you need to bomb out (or some evil DBA kills your session for running too long) the temp table contents just disappear. No clean up needed.

Maybe the above is not so fair, I have not been a proper PL/SQL developer for a while now, but I hardly see the above used. Especially Savepoints. I can’t remember not having savepoints available (hmm, maybe Oracle 6) and Autonomous Transactions and Temporary tables are Oracle 8 (I thought Temporary tables might be 9 but Tim Hall’s OracleBase says 8)

Another thing I have noticed over the years is that so often I will read up on some oracle feature I know little about, only for it to come up in the next few weeks! There is a psychological aspect to this, that we only remember these “coincidences” and not the more common situations where we read up on something which does not subsequently come up before we forget about it, but I think that it is also that we tend to use only a few solutions to solve the problems we see and adding another solution to our list means the chances are high it will be suitable for something soon.

OK, so it would help us all to read the manuals (or other Oracle technical books) more. Now the big problem is finding the time.

Why Present (UKOUG TEBS 2012) November 27, 2012

Posted by mwidlake in Friday Philosophy, Presenting.
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The annual UK Oracle User Group Technical and E-Business Suite conference is fast approaching and rather than just say “hey everyone, I’m going to present at a conference” I thought I would say why I present at conferences (and SIGs (and any opportunity I get) ).

The UKOUG TEBS conference is the one that is, in my eyes, the UKOUG conference. It covers E-business suite and the core database stuff – DBA-type things and developer-type things. The things I am interested in. You can see the details and agenda via this link. If you would like to see someone else’s view of this year’s conference, from a delegate’s perspective, check out this post by my friend Big Dave Roberts. I’ve said it before and I’ll say it again, I’ve personally got more out of the UKOUG TEBS conference than when I have been lucky enough to go to Oracle Open World. For me, I want to see user stories and opinions as well as the Oracle company line – and user groups give far more of that. UKOUG is the biggest and most encompassing of the European conferences, but check out and attend your local user groups if you are not based in the UK (or are in Scotland) – I’ve been to a couple now and all have been good.
{Oh, I should add, I am not presenting at the main TEBS conference, for the first time that I’ve made it there in…10 years! I’m presenting on the OakTable Sunday. I get to fully enjoy the whole 3 days of TEBS this year, as a normal punter!}

So why do I present?

First up, I am lucky that presenting does not scare me. Oh, I get nervous before I start and I worry about my material and doing a decent job of it, but I never feel sick or faint before starting(*). I’ve got some good friends who know as much or more about database technology than I and, in a social situation, they will let fourth with eloquence and passion about some topic. Usually in a pub. But the idea of formally presenting fills them with the heebie-jeebies if not the screaming abdabs. Or, when they get up to talk, they morph from erudite and eloquent {ie they speak clearly, concisely and interestingly) into stuttering, uncomfortable rabbits caught in the lights. And they quickly drop back from it. It’s a real shame as they have a lot to say. Actually, it is a blessing as it leaves space open for me :-)

Secondly, I want to be noticed. There, I’ve said it. I’m pretty sure that 75%+ of the regular speakers at conference want to be noticed and that is a factor in why we do it. Oh, of course, we can wrap it up as “marketing your skills” or “maintaining a presences” but that’s fluff. We want you to see us talk and we want you to like what you see. Well, not the physical aspect of it, that would be weird, but we want you to either think we know what we are talking about or enjoy listening to us prattle on. We want to be appreciated. That’s not so noble, huh? But true.

As a sub-topic to “I want to be noticed” let’s deal with getting work. For me personally, speaking has never got me a job. Asking around friends and contacts most people are the same in that Presenting does not get most of us any work. Maybe it’s a factor when I get interviewed but no one has once come up to me after a talk and said “can you come to our site and be paid a vast sum of money to solve this problem”. I’d love you to be the first, though…

Third, and this may seem noble – or corny or self-worthy – but I talk because I want to teach. I want you to have in your head the knowledge I have in mine, preferably with less pain and anguish than it took me to get it in mine. I love teaching people stuff. It is a common trait to the OakTable network. We teach and we demonstrate why we think what we think. Usually. I can’t decide if I prefer making something that is broken work or teaching people more. Those two are why I do what I do. Frankly I gave up on making a “significant difference” years ago, I’ll stick to making lots of insignificant differences.

Fourth, I get to meet people. It’s taken a while as, except in small groups, I am not great at being sociable. That might seem odd given I said I like to be noticed, but I don’t like to be noticed as a fool and for reasons I will side-step, I’m not too great at judging how I am coming across. Plus I cannot remember names or faces, which is tricky sometimes. Actually, a lot of actors are not “social people”, for some they act because they can’t “do” people. Anyway, presenting has opened doors to me by meeting other presenters who know their stuff, non-presenters who know their stuff and, generally, people. Most of whom have been nice.

Fifth, and this is quite rare. I get asked. If you ask me to present the chances are I will say “ohh, yes please!!!!” We are back to my second point about being noticed, aren’t we? Caveat. If you ask me to present and you live thousands of miles from the UK, as I have no employer to fund my demands for limousines and four-star hotels, I might have to say no. Unless you buy me a LOT of beer.

That is why I present. You probably now expect me to say something to encourage you to present but, mehh, if you want to, just do it. If you don’t, don’t do it. It’s not for everyone. Except you over there. Yes, you know who you are. You need to present more. :-)

(*) I confess, when I do a talk that is aiming to be funny, I get very nervous. When I do my “disasters” talk I can get very nervous as the whole idea is that people will be amused. If I get the feel of the talk wrong I can look preachy or obnoxious or bitter or daft or all four and more. But it is still the talk I most enjoy giving.

Friday Philosophy – The Importance of Context November 23, 2012

Posted by mwidlake in Friday Philosophy, Perceptions.
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1 comment so far

A couple of weeks ago I was making my way through the office. As I came towards the end of the large, open-plan room I became aware that there was someone following behind me so, on passing through the door I held it briefly for the person behind me {there was no where else they could be going}, turned left and through the next door – and again held it and this time looked behind me to see if the person was still going the same way as I. The lady behind gave me the strangest look.

The strange look was reasonable – the door I’d just held for her was the one into the gentleman’s bathroom. *sigh*

I was doing the correct thing, I was attempting to be helpful to a fellow person, I was in fact being very polite. But because I had utterly failed to consider the context, there is now a lady who works on the same floor as I who considers me, at best, as strange. At worst she thinks I am very strange – and more than a little creepy. I fear the latter given her reaction when she saw me in the kitchen area recently and turned around. {By the way, if anyone can think of a good way I can clear this up I’d appreciate it. After all, I can’t exactly go up to her and say “sorry about holding the door to the gents for you the other day, I did not realise you were a woman”}.

My point is that you can do what you believe is the right thing but, because you are not thinking of the context or are unaware of the full situation, you end up giving utterly the wrong impression. I had a work situation like this a while back.

Without going into too much detail, I was working with a client on a data warehouse project. The Oracle database bulk-processed large quantities of data, did classic big-data queries and was sitting on some fairly expensive hardware with dedicated storage and the intention of implementing Dataguard. One of the issues they had was with a subsidiary part of the system that created a very large number of small transactions, lots of updates. High volume OLTP on a DW setup. It was hammering the storage and eating up all the available IO. The data for this subsidiary system was transient, no need to protect it.
I realised that the hardware was not correct for this subsidiary system and it needed no archived redo. Archiving redo is an all or nothing situation for an Oracle instance. So happy that I had worked out what to do I proposed {with a smile} moving the subsidiary system to it’s own database on it’s own hardware.
When I said this to the client, their response was a stony look and the comment “We’ve just spent a fortune on this platform……”. Having dug my hole I proceeded to jump right in there “It’s OK, what I am proposing is only about 5, 7 thousand pounds of kit – nothing compared to what you spent already!”. The client now got very, very annoyed indeed.

You see, the context is that they had been sold a system that was very expensive – it was to do a demanding job. They had been getting poor performance with the system and that is partly why I was there. They also did not really understand the technical nuances well (at least, not the chaps I was talking to) and they did not appreciate why I said what I did. From their perspective, this smiling loon was suggesting that a system costing 2-3% of what they had spent on their data warehouse platform was going to be able to do the processing that the expensive system could not. Either they had spent waaay too much, this new “expert” was an idiot or else I was lying to them. And they did not like any of those options.

Looking back it is clear I should have been more aware of how they would receive what I said. I’ve done this before {several times}, bounded into a situation like a wide-eyed puppy and gone “Look! We can just do that!” without considering things like upsetting the guy who had suggested the original solution, or making the on-site expert look stupid or blowing away a salesman’s pitch. Or that I have missed a glaring and valid reason why they can’t “just do that”.

I suspect that a few people would say “no, you just tell them the way it is and if they don’t like it or you upset someone then tough”. Well, maybe, but not if you want to be there to help fix the next problem. Also, I know I am not great at appreciating the context sometimes. That is part of why I will never run a company or be a senior manager, I lack the skills to judge the impact of what I propose or say sometimes, in my rush to be helpful. I am slowly learning to just hold back on ideas though and to run things past friends or colleagues with more “whole picture” skills first though. I might be rubbish at it but I can learn I am rubbish at it.

In the case of the situation above, the expensive system was correct for what they wanted to do – and maybe not quite expensive enough. I was suggesting a slightly unusual fix for a specific problem and I should have been more laboured in explaining the problem and more circumspect in leading them to the solution. I should have taken more time.

I should have checked who was following me and where I was going before I held the door open.

Friday Philosophy – Is the CBO becoming way too complex? October 19, 2012

Posted by mwidlake in Friday Philosophy, performance.
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20 comments

I was at the SIOUG annual conference in Slovenia this week (and a very good conference it was too) and I was watching a presentation by Christian Antognini about how the CBO learns by it’s mistakes. This was of course mostly about adaptive cursor sharing and cardinality feedback. Chris was also able to share a few tid-bits about 12c enhancements in this area. I can’t go into details, but basically it looks like the CBO is going to not only enhance those two features but there is a new one where the CBO can change the plan on the fly, as the same query progresses.

As I watched the presentation I found I was in two minds about this. Part of me was thinking “Yes, these features do help in the CBO realising it has chosen a poor plan and improving things for the next execution – and it will get better at it”. The other part was thinking “Oh dear, yet another source of confusion and of performance of queries changing when ‘nothing has changed’“.

It also solidified an idea I have for a new presentation, about how what you see in the execution plan may well not be what is actually executed. ie there are optional bits in there that do not get run at execution time, depending on the results of prior steps.

But I digress. What I ended up wondering at the end of Chris’s talk was this. Is the CBO getting just too complex? It is all very good that extra abilities are being added so that there is a better chance of a good plan being chosen in the first place and the various ways we can control the choice of the plan grows and grows. But we are long past the point when you could write even a simple sql statement and know what the plan will be before you explain it – let alone run it, check the plan and then run it again a few minutes later and be sure the plan will be the same.

Why does this bother me? For three reasons:

1) Performance will not be stable, so the user experience will not be consistent – and so they will be unhappy. Users will generally be happy if they run a report and it takes one minute, if it takes one minute each time. If it takes one minute and then it takes 5 seconds, they want it to always run in 5 seconds, else they fell cheated or that the system is broken. In fact, I am pretty sure a user will be happier if a report always takes 2 minutes rather than it take 5 seconds or 40 seconds but they never know which! (So long, that is, that they never, ever see it run in less than 2 minutes).

2) If performance of a particular SQL statement is absolutely crucial, I need to know how the CBO can and probably will satisfy it so that I can work that into my solution. Otherwise I am reduced to trying out informed options (or maybe random changes :-) ) in order to find the optimal solution – and I cannot be sure that the plan won’t suddenly swap later unless I fix the plan. OK, it might swap to be faster, but I only notice when it swaps to be a lot slower.

3) I’ve said this before, but I am starting to really wonder how anyone new to this starts understanding oracle performance tuning any more. Reading blogs and books about how Oracle works and what impacts the CBO teaches you a lot about what is possible but it only makes sense when you do little tests and proofs of concepts. ie you actually run simple examples and see what happens. But with all these options, considerations and now on-the-fly alterations to plans by the CBO, it is very confusing. Even I, after 20 years of doing performance tuning on and off, am constantly finding myself looking at relatively simple SQL and having to work out why the plan is as it is and satisfying myself that it has not changed. I started with the CBO when it was a lot simpler and I’ve been introduced to the complexities gradually, as they have been introduced, so learning about it has been easier for me.

Perhaps I should not worry about this. I mean, the CBO is getting better at doing what it does, that is good. It is getting hard for those younger and smarter than me to learn about it, so my career is protected. And there is more stuff to talk about so I can keep going to conferences and talking about them.

And with that happy idea, I’m off to start the weekend. Where was that cork screw?

Friday Philosophy – Work Inside Life August 24, 2012

Posted by mwidlake in Friday Philosophy, off-topic, Private Life.
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I know, the usual phrase is “Life Outside Work” but I like to think that, no matter how much we may like our jobs, our overall life is the key thing.

I was prompted to write today’s Friday Philosophy when I was reading Neil Chandler’s blog a few days ago and saw that he had posted about his up-coming {and now in progress} Banger Rally. He and some mates are doing something very cool in their spare time, taking part in a rally from, basically, Calais in France to Naples in Italy, in a “banger”. This is a UK (and wider?) term for an old, tired, worn out car. The most they could spend on the car was £250 and it has to go over some pretty extreme mountain passes. I presume it also has to carry the set of 4 people involved too, so not a lot of weight there then, Neil :-). You can follow their progress at this blog. I was in a pub in Leeds with Neil when he was considering one car for this rally.

I can’t claim that I do anything as striking as Neil’s current jaunt when not working, but I do like to spend some time doing things that are nothing to do with IT at all. For me, this tends to be physical tasks like cutting down trees with my chainsaw. Or building structures in the garden with wood (OK, half-building them – I constructed the below platform and another out into our pond maybe 18 months ago, both still have no balustrade around them and there is a 45cm gap between the bank and the pond platform – NEXT weekend I’ll maybe finish one. Maybe.)


Another garden task recently was building our wood-fired, mud-constructed pizza oven. My wife and I went on a 1-day course to learn how to make a mud-based pizza oven and then spent, ohhhh, about 10 days over 8 weeks building one! We dug a big hole in the garden to get some clean clay (we live in an area that is on top of clay), stole some straw from the horse that lives at the bottom of our garden (long story), bought some sand (because nicking it from beaches is both illegal and bad form) and mixed up our first batch of clay-sand-straw. Add in some old bricks and we got started. It took about 30 lots of mixture, a few alterations to the ratios as we went, but we ended up with this monster.

If you are wondering what the white stuff on the oven is, some ants decided to build their nest in the oven, between the layers I guess (you build the inner oven first and then add several extra mud layers to give insulation and a larger thermal mass, so that the oven stays warm longer).

Like anything, if we did it a second time we would probably make a much better job of it as we learnt so much from the first attempt. One of them was to invite friends with young children over to see us during the build. Kids love the idea of treading the mud mix and you can get a suprising amount of work out of a single ten-year-old (and very insistent I get the age right) German girl if they are allowed to get very muddy.

I found the whole process very relaxing (but very tiring) as you do not need to use too much brain power, slapping the mud mixture on the outside is deeply cathartic and you end up with something useful. Well, slightly useful.


Having built it we then had to learn how to fire it. As an ex-boy-scout I thought this would be easy. Getting the fire going is not too hard, you need to keep it burning well for about an hour to heat up the oven and, one big tip, don’t use any damp wood or wood that “spits” (like willow). Having a burning log explode and shower your almost-ready pizza with charcoal embers can lead to angry garden scenes and considerable bad language.

We can just about get a 9″ pizza in there. The pizza in this shot is actually about 6″. The oven was designed to take a 12″ pizza but, errm, I forgot to allow enough space to one side to push the fire into as well.

Another major thing to keep in mind? That arch! You can’t put anything in the oven that is larger than that hole. More importantly, you can’t get anything out that won’t easily come back through that hole. Sticking your arm inside to jiggle things about is also tricky as it gets up to around 300C! {for US readers – about a millon F}

As you can see, the results are anything but professional! And, compared to nipping down to the shops to buy a pizza and just slamming it into the kitchen oven, it takes a lot, lot longer. But you can drink beer or enjoy a bottle of win and sit in the garden whilst getting the mud oven fired and hot. Last weekend we had friends over and the ladies made the pizzas, I cooked them and the other gentlemen helped us work through the beer collection and ate. As for taste? Fantastic.

My wife is far more artistic than I and she makes decorative cakes, sews and now even makes hats when not auditing IT systems (Have you ever been involved in an IT audit and the person knows how to make lists and check them – but can’t plug in a PC? Well, Sue was once a DBA and also a Unix Sys Admin, so when she audits you, she finds what you are hiding!). As such, maybe as an industry we should encourage her hat-making

So what, if anything is the point of this Friday Philosophy, other than to show off my pizza oven and my wife’s hats?

Well, I see this outside work activity as important in the workplace as well, especially if you are having to manage people. Firstly, it is important, I feel, for us all to do something we really enjoy to relax and re-energize (and this can be “computers” for IT people, but as I get older I notice more of my friends who were utterly technology-focused in their 20’s are now moving more towards non-IT hobbies).

Secondly, what people do in their spare time can tell you a lot about the person and what keeps them happy. If they have hobbies that are artistic and their IT job is very regimented, it could indicate they would be happier with some more less rigid task in the mix, say some design work. If they have NO outside hobbies, you are probably working the poor dears a little too hard!

Thirdly, and I have seen this for real, you may have a person or a team that is not performing well in the office – but it turns out a lot of them do interesting and challenging things at home. Someone who can motivate themselves to be a part-time fireman or has the dedication to train each day for a sport has skills and energy. Why, as their manager, am I not seeing much of these traits in the office? Because they are not happy and/or motivated. So I have an issue to sort out. I don’t manage people at present, but I still find it interesting what people do and achieve outside the office as it can indicate that they have talents and skills not being seen in the workplace.

I wonder how I can introduce my chain-saw skills into performance tuning?

Friday Philosophy – New Game: Phone Zombies! (You Too can Play) August 17, 2012

Posted by mwidlake in Friday Philosophy, humour, off-topic, Perceptions.
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8 comments

I’m spending a lot more time in Central London at the moment due to current work commitments. A few weeks ago I was having a quiet stroll through the streets and had what I can only describe as an odd moment:

I looked around and found I was being converged upon by 5 or 6 people walking slowly and aimlessly towards me – all from different angles, all only vaguely aware of their surroundings, all looking like they were making straight for me. I instantly thought of one of the scenes from “Shaun of the Dead” {A cracking film, go hire it tonight}.

They were all on their smart phones of course, intent on the little glowing screens of whatever it was they could not drag their eyes from – despite them also trying to navigate a busy city landscape. As some of you know, I have a bit of a “hate-mild dislike-grudging acceptance” relationships with Smart Phones.

I was so struck by this scene that I nearly did not move in time, but finally I did step to one side as I watched them do this quite wonderful, little, shuffling-dance around each other. I think only one of them actually looked up properly, the others all did that micro-glance; frown; direction shift; re-engage-with-screen procedure that is becoming so common. As a species we must be somehow pre-designed to cope with this as none of them actually bumped into each other – but it took several micro-glance manoeuvres for some of them to make it through.

This has resulted in a new game I can’t stop playing as I make my way through London:

Phone Zombies – How many people can I see at any time who are effectively lobotomised by their personal electronic device?

I have a few rules:

  • I has to be an electronic device – phones, smart phones, crackberries, tablets, electronic books etc.
  • Real books and papers do not count.
  • They must be upright (so no sitting).
  • If they are moving they count.
  • If they are stopped in the middle of the path they count.
  • If they have put themselves in a doorway or some other sensible place they do not count.
  • Unless, even though they have done that, they are still e.g. blocking ingress and egress from the doorway.
  • A bonus point if they micro-glance manoeuvre.
  • 5 bonus points if contact is made with another person in the time I am watching.
  • 10 bonus points for contact with something inanimate {only once to date}.
  • 20 points if they go “uuurrrgggghhh” and have blood on them. {no one has got 20 bonus points yet, but I live in hope}

I think my best so far is about 14, but that is because two phone-zombies both walked into each other. Classic.

Friday Philosophy – I Am An Exadata Expert August 10, 2012

Posted by mwidlake in Exadata, Friday Philosophy, Perceptions.
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5 comments

(Can I feel the angry fuming and dagger looks coming from certain quarters now?)

I am an Exadata Expert.

I must be! – I have logged onto an Exadata quarter rack and selected sysdate from Dual.

The pity is that, from some of the email threads and conversations I have had with people over the last 12 months, this is more real-world experience than some people I have heard of who are offering consultancy services. It’s also more experience than some people I have actually met, who have extolled their knowledge of Exadata – which is based solely on the presentations by Oracle sales people looking at the data sheets from 10,000 feet up and claiming it will solve world hunger.

Heck, hang the modesty – I am actually an Exadata Guru!

This must be true as I have presented on Exadata and it was a damned fine, technical presentation based on real-world experience and I have even debated, in public, the pros and cons of point releases of exadata. Touching base with reality once more, I did an intro talk “the first 5 things you need to know about Exadata” and the “debate” was asking Julian Dyke if he had considered the impact of serial direct IO on a performane issue he had seen and he had not only done so but looked into the issue far more than I – so he was able to correct me.

But joking aside –  I really am a true consulting demi-god when it comes to Exadata

I have years of experience across a wide range of Exadata platforms. That would be 0.5 years and I’ve worked intensively on just one system and am in a team now with some people who are proper experts. So a range of two. Yes, tongue is still firmly in cheek.

This situation always happens with the latest-greatest from Oracle (and obviously all other popular computing technologies). People feel the need to claim knowledge they do not have. Sometimes it is to try and get consultancy sales or employment, sometimes it is because they don’t want to be seen to be behind the times and sometimes it is because they are just deluded. The deluded have seen some presentations, a few blog posts and maybe even got the book and read the first few chapters and are honeslty convinced in their own minds that they now know enough to make effective use of the technology, teach {or, more usually, preach} others and so proclaim on it. {See Dunning Kruger effect, the certainty of idiots}. I’m certainly not arguing against going to presentations, reading blogs and books and learning, just don’t make the mistake of thinking theoretical, second-hand knowledge equates to expert.

With Exadata this situation is made worse as the kit is expensive and much of what makes it unusual cannot be replicated on a laptop, so you cannot as an individual set up a test system and play with it. Real world experince is required. This is growing but is still limited. So the bullshit to real skills quotient remains very, very high.

If you are looking for help or expertise with Exadata, how do you spot the people with real knowledge from the vocal but uninformed? Who do you turn to? {NB don’t call me – I’m busy for 6 months and I really am not an expert – as yet}. If your knowledge to date is based on sales presentations and tidbits from the net which may or may not be based on a depth of experience, it is going to be hard to spot. When I was still without real world experience I had an unfair advantage in that I saw email threads between my fellow OakTable members and of course some of those guys and gals really are experts. But I think I was still hoodwinked by the odd individual on the web or presenting and, I can tell you, though this background knowledge really helped – when I DID work on my first exadata system, I soon realised I did not understand a lot about the subtulties and not-so-subtulties of using a system where massively improved IO was available under key conditions. I had to put a lot of time and effort and testing to move from informed idoit to informed, partially experienced semi-idiot.

I know this issue of the non-expert proclaiming their skills really frustrates some people who do know their stuff for real and it is of course very annoying if you take someone’s advice (or even hire them) only to find their advice to be poor. Let’s face it, is is simple lying at best and potentially criminal mis-selling.

I guess the only way is for peopel needing help to seek the help of someone who has already proven themselves to be honest about their skills or can demonstrate a real-world level experience and success. I would suggest the real experts should do that most difficult task of pointing out the mistakes of the false prophets, but it is very tricky to do without looking like a smartarse or coming over as a big head or jealous.

I’ll finish on one thing. Last year I said how I thought maybe I should do more blog posts about things I did not know much about, and be honest about it and explore the process of learning. I did actualy draft out about 3 posts on such a topic but never pushed them out as I was way too busy to complete them… That and, being candid, I really did not want to look like an idiot. After all, this Oracle lark is what puts beer in my hand, hat fabric on my wife’s millinary worktop and food in my cat’s bowl. The topic was….? Correct, Exadata. Maybe I should dust them off and put them out for you all to laugh at.

Friday Philosophy – Whatever Happened to Run Books? July 27, 2012

Posted by mwidlake in Friday Philosophy.
Tags: ,
3 comments

I realised recently that it is many years since I saw what used to be called a Run Book or System Log Book. This was a file – as in a plastic binder – with sheets of paper or printouts in it about a given system. Yes, this was a while back. It would often also have diagrams {occasionally drawn by hand on scraps of paper – so that would be the database ERD then}, hand-written notes and often the printed stuff would have scribbles against it.

{BTW I asked a colleague if he remembered these and when he said he did, what he used to call them – “err, documentation???”. Lol}

There was one book per key system and you could tell if a system was key (that is, Production, or a development system where a large development manager would punch you in the eye for losing anything, or any system the DBAs wanted) as it had a run book. It held information that was important about the system and, although you could look up most of it when logged onto the system itself, was useful to grab and just check something. However, it was vital if you had to recover the system.

Being a DBA-type, the run books I used to see and use were database focused. The front page would have the SID, name, host name (and even the spec of the host), version, tnsnames info, block size, backup strategy and schedule and, very importantly, the system owner. Yes, the big guy who would be upset if you lost the system. In there you would have printouts of the tablespaces, datafiles and sizes, the backup script, users (and passwords, very often), reference data tables, filesystem layout, OS user details and anything else
needed to recover the system.

This was an evolving and historical set of data. I mentioned above that you would have maybe scraps of paper from when a design session had come up with an alteration to the system. Corrections would often be done by hand. When you printed off the tablespace sizes on Monday, you did not throw the old one away but just added the new one, so you had information about the growth of the DB going back in time. Once in a while you might thin out the set but you kept say one a month.

It was actually that which got me to thinking about runbooks. At a site recently one of the DBAs was asking me if I knew of a screen in OEM that showed the growth of space used over time and my immediate thought was “well look in the run book” {I was very tired that day and losing my grip on reality}. Not being able to find a screen for what he wanted and knowing the data in OEM/AWR was only going back a month anyway, I suggested a simple spreadsheet that he could maintain. With the run book you could flip to the printouts of tablespace sizes, grab a piece of paper and do something lo-tech like this:

This would take less time than firing up Excel, typing the figures in, getting the graph wrong 3 times and then printing it out. Though if you had to go show Managers how the data was growing, you invested that time in making it pretty {why do high level managers insist on “pretty” when what they really want is “informative”?}

So why have Run Books gone {and does anyone out there still use them, in physical or electronic format}? It certainly seemed standard practice across IT in the 80’s and 90’s. I suspect that the reason is that most of the information that used to go into them is now available via online GUI admin tools and looking at them is actually faster than going and grabbing a physical book. Besides, if your DBA or Sys Admin team is split between UK, India and Australia, where do you keep a physical book and allow everyone to check it? I have vague memories of electronic Run Book applications appearing but they never seemed to get traction.

That is one of the drawbacks of using GUI admin tools. No, this is not just some tirad by a bitter old lag against GUI tools – they are generally a massive improvement on the old ways – but they are not perfect. Most of them only hold a short history and printing out the data is often tricky or impossible. All you can really do is screen dumps. No one has those little scripts for listing out basic information anymore {except us bitter old lags} as they have GUIs to do all that and, heck, I can’t go printing off a load of stuff on paper and sticking it in a binder – that is so 20th century!

Maybe I’m being unfair and OEM has a “run book” section I have simply never seen – but I’ve never seen it. If it is/was there, how many people would use it?
I do miss the Run Book though. Especially the ease with which I could look up all those passwords…

Friday Philosophy – Presenting Leads to Drinking, Discuss June 15, 2012

Posted by mwidlake in Friday Philosophy, humour, Meeting notes, UKOUG.
Tags: , ,
9 comments

Just a quick Friday Philosophy {the day job is very demanding at the moment, thus the silence on the Blog front}

I’m presenting in Leeds at the start of July on UKOUG AIM SIG on “The First Few Things You Need To Know About Exadata”. As part of the final preparation of the agenda it’s been raised that we should have a beer after the event and put it on the agenda.

Now, when I ran the Management and Infrastructure SIG, there was always a last item of “retire to a pub for a drink or two”. It is a common feature of technical UKOUG SIGs and a great opportunity to chat to the speakers more.

Chat to the speakers. Now I think about it, most of the speakers always make it to the pub after a SIG. If the attendance on the day is 10% speakers, 10% committee and 80% delegates, the make-up in the pub will be 30% speakers, 20% committee and 50% delegates, or similar.

At conferences, the bars in the evening are covered in speakers (all still speaking – loudly and {usually} drunkenly).

So, is it that:

  • Speaking leads to elevated drinking
  • Drinking makes you more of a sucker for speaking
  • Speaking and Drinking have a shared genetic basis
  • It’s just me.

My excuse is that all that hot air coming out my mouth makes it dry and it needs a little wetting afterwards…

You Will Be Our Slave – Err, no, I Won’t May 27, 2012

Posted by mwidlake in contracting, Friday Philosophy, rant.
Tags: , , ,
10 comments

For the sake of current clients, this posting has been time-shifted.

I’m looking at the paperwork for a possible new job in front of me. Document seven out of 13 is the Working Time Directive Waiver. It’s the one where you sign on then dotted line saying your proposed new client can demand more than 48 hours of work a week out of you. {This may be UK or European Union specific but, frankly, I don’t care}.

I’m not signing it. For one thing, I doubt the legality of the document under EU law – especially in light of the issues the UK government had with this and junior doctors {who often, and still do, end up making life-deciding decisions on patients when they are too tired to play Noughts and Crosses, having worked 80 hours that week}. For another, well, I don’t give a damn. I ain’t signing it.

Now, I’ve just completed about 60 hours this week for my client. Not a problem at all, something needed doing, I could do it and so I have. I have done, am doing and will continue to do long weeks for clients when there is a business need and it fits in with the rest of my life and it is not a chronic situation {chronic is a medical term that means “long lasting and on-going”}.

If I am doing 60 hours plus every week, that means I am trying to do 2 people’s job at the same time and doing both of them badly. I don’t care how great I am at doing what I do, if it is 60 hours each and every week, I’m doing it badly because I am too stressed and tired to be doing it well. Also, where is the rest of my life? I have no “rest of my life”.

If my client is asking me to do 60 hours this week and I say “no” and they sack me under the Working Time Directive waiver – that means it is not a request, it is an enforcible demand. I am their slave. Nope. Not happening. It is best all round if it is acknowledged up front before I arrive on site that the client may ask and I may well say yes – but I can say no.

I know, some of you will be reading this and saying “but I need my job and if that is what it takes, I do it”. Well, I’ve worked for 20+ years and I’ve realised that (a) there are organisations that don’t abuse you and (b) you actually get little real payback for those ridiculous hours. But it can ruin your non-work life, even your family life. I don’t need any individual job and I am bloody well not playing those games any more. Employment in a modern, democratic society is supposed to be a mutual agreement and, if is it not, I ain’t playing. That is my small win for all those years of grind and I’m insisting on it.

I know, some of you will say “look, it never comes to anything, just sign it and ignore it like the rest of us”. No. If you are right, it is a corporate lie and is not required. And, to my detriment, I know you are wrong and sometimes there is an attempt to enforce it. If you cannot get me to do the 60 hours by asking and explaining, either you do not have a valid reason {and history proves I am an utter push-over to a half-reasonable request} or there is a reason very important to me why I can’t comply. If you try and insist, you really are treating me like a slave. That empty space? That’s me having gone for a looong walk.

I am not signing a document saying “you can demand I work over 48 hours any and all weeks you like”. Your are not signing a form saying “I can demand any time off I like week in and week out”. All contracts have a clause saying “this is not working between us, we will curtail the agreement”. We will use that if need be, not a bullying document that says I am your slave.

I am not signing.

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