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New York Oracle User Group Fall Conference Materials

Thank you all who attended my sessions at NYOUG Fall Conference this morning. I appreciate spending you most precious commodity - your time - with me. I sincerely hope you found both the presentations enlightening as well as entertaining.

Please see the details of the sessions below along with the download links.

Keynote: Oracle 12c Gee Whiz Features

Yet another Oracle version is out and so are about 1500 new features in a variety of areas. Some are well marketed (e.g. pluggable database or the multitenant option) and some shine by their sheer usefulness. And there are some that do not get a whole lot of coverage but are are hidden gems. In this session you learned 12 broad areas of Oracle Database 12c I feel are worth learning about to make your job as a DBA or developer better, easier, smoother and, in some cases, even make it possible what was hitherto impossible or impractical.

DBMS_APPLICATION_INFO for Instrumentation

I just wanted to put up a post about DBMS_APPLICATION_INFO. This is a fantastic little built-in PL/SQL package that Oracle has provided since Oracle 8 to allow you to instrument your code. i.e record what it is doing. I’m a big fan of DBMS_APPLICATION_INFO and have used it several times to help identify where in an application time is being spent and how that pattern of time has altered.

Some PL/SQL developers use it and some don’t. It seems to me that it’s use comes down to where you work, as most PL/SQL developers are aware of it – but not everyone uses it (a friend of mine made the comment recently that “all good PL/SQL developers use it“. I can understand his point but don’t 100% agree).

Friday Philosophy – Lead or Lag (When to Upgrade)?

I was involved in a discussion recently with Debra Lilley which version of Oracle to use. You can see her blog about it here (and she would love any further feedback from others). Oracle now has a policy that it will release the quarterly PSUs for a given point release for 12 months once that point release is superseded. ie once 11.2.0.3 came out, Oracle will only guarantee to provide PSUs for 11.2.0.2 for 12 months. See “My Oracle Support” note ID 742060.1. However, an older Terminal release such as 11.1.0.7 is not superseded and is supported until 2015 – and will get the quarterly PSU updates. This left the customer with an issue. Should they start doing their development on the latest and theoretically greatest version of Oracle and be forced to do a point upgrade “soon” to keep getting the PSUs, or use an older version of Oracle and avoid the need to upgrade?

Oracle Nostalgia

When preparing the material for my “Oracle Lego – an introduction to Database Design” presentation for the UKOUG last week, I was looking back at my notes from a course on the topic from “a few years back”. There were a few bits which made me smile.

Oracle’s [SQL] implementation conforms to ANSI standard, although referential integrity will not be enforced until version 7

Lack of Index and Constraint Comments

Something I’ve just reminded myself of is that under Oracle you cannot add a comment on an index or a constraint. You can only add comments on tables, views, materialized views, columns of those object types and a couple of esoteric things like Operators, Editions and Indextypes.

Here is an example of adding comments to tables and columns:

What Have I Let Myself in For! – UKOUG this year

One of my favourite Oracle happenings of the year is fast approaching, the UK Oracle User Group technical conference {see/click on the link on the right margin}. I’ve blogged before ( like here, last year) why I think it is so good.

I try and present at the conference each year and I go no matter if I am presenting or not.

However, this year I think I might have got myself into trouble. I put forward 3 talks, expecting one or possibly two to get through. One on Index Organized Tables, one on IT disasters and one as an introduction to database design – I’ve moaned about it being a dying art so I figured I should get off my backside and do something positive about it. Each talk is in a different stream.

IOT P6(a) Update

In my last post, IOT part 6, inserts and updates slowed down, I made the point that IOT insert performance on a relatively small Oracle system was very slow, much slower than on a larger system I had used for professional testing. A major contributing factor was that the insert was working on the whole of the IOT as data was created. The block buffer cache was not large enough to hold the whole working set (in this case the whole IOT) once it grew beyond a certain size. Once it no longer fitted in memory, Oracle had to push blocks out of the cache and then read them back in next time they were needed, resulting in escalating physical IO.

Friday Philosophy – The One Absolute Requirement for System Success

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.

In Defense of Agile Development (and Their Ilk)

In my previous post I asked the question “why doesn’t Agile work?”. I’m not sure the nuance of the question came over correctly.

I’d just like to highlight that the question I asked was “Why does agile not work”. It was not “Why is Agile rubbish“. I’ve said a few times in the past couple of weeks that I like the ideology of Agile and I am (and have been for years and years) a strong proponent of prototyping, cyclic development, test driven design and many other things that are part of the Agile or XP methodologies.

That distinction in the title is a really important distinction and one I’d hoped I’d made clear in my post. Looking back at my post though, I think it is clear I failed :-( . I highlighted reasons why I think Agile does not work and in my head I was thinking “if we avoid these, Agile could work” – but when you write something down it does not matter what is in your head if it does not reach the paper.

I’m actually frustrated that in the last few years I have not seen Agile really succeed and also that this must be the normal situation, going on the response you get when the topic of Agile comes up with fellow technicians and comments on my own blog.

However, on that post about Agile two people who’s opinion I deeply respect came back at me to say “Agile does work!”. Cary Millsap, who many of you will have heard of as the “Method R” guy and the person behind Oracle Flexible Architecture. And Mike Cox, who most of you won’t have heard of but Mike taught me a lot about sensible development back in the 90′s. He’s one of the best developers I have ever had the pleasure of working with and I know he has had great success with Agile and RED. I’m not sure if they read my post as “Agile is Rubbish” or they are, like me, simply frustrated that it can work but so often does not.

So I’ve been thinking about this a lot this weekend and I was helped by Cary’s paper on the topic that he mentioned in his comment. I’d highly recommend downloading it as it is an excellent description of not only why Agile can help but describes how and some of the pitfalls {I’d started my own post on that, but go read Cary’s}. I should add, you can see Cary present his case for Agile at the UKOUG conference this year.

So where does this bring me to? Well, I think “Is Agile good or bad” has become almost an “IT religion” topic, people love it or loath it and it is based on what they have seen of the methodology in real life. No, that’s wrong, it is based on what they have seen that has been labelled with that methodology in real life. Or worse, it is based on anecdotal opinion of those around them. The thing is, if you look at what XP is supposed to consist of or what Agile Programming is supposed to consist of, most of us would agree that a great deal of it makes sense in many situations. I’d disagree with some of the details in Cary’s paper but overall I’m in strong agreement. Sadly, What Agile and XP is supposed to be is not well matched by what you see on the ground in most cases. So even if these methodologies are right for the situation, what has been implemented is not the methodology but probably more a slap-dash process that simply jettisons documentation, design and proper testing. This whole thread sprung from my lamenting the demise of database design and several of the comments highlighted that the introduction of Agile seemed to equate, at least in part, with the demise of design. As MIke and Cary say, and as I think anyone who has successfully utilized Agile would say, Design is an integral part of Agile and XP methodology.

Agile can and does work. But many things can and do work, such as taking regular exercise to keep healthy or regularly maintaining your house to keep it weathertight. Like Agile, both take effort but the overall benefit is greater than the cost. And like Agile, do it wrong and you can make things worse. If your window frames are starting to rot and you just slap a new layer of top-coat on them all you will do is seal in the damp and rot and hide the problem – until the glass falls out. Going for a regular 5 mile run is good for you – but not if you are 10 stone (60KG) overweight and have not run in years. A 5 mile run is also not a good idea if you want to be a long-jumper. Right training (methodology) for the right aim. Also, just like keeping healthy, house maintenance or anything that takes effort but works, proponents tend towards extremism – probably as a reaction to the constant {perceived} pig-headedness of critics or the failure of people to just do what now seems so sensible to them {think reformed smokers}. I’ll have to buy Cary and Mike pints to make up for that jibe now, and promise them it was not aimed at them personally…

Sadly, the reality is, Agile does not work 90% of the time it is tried. So, does that mean Agile is actually rubbish? Or at least, not fit for purpose, because many companies are not able to use it? Companies are there to achieve something and the IT systems are part of achieving that something. If Agile cannot aid that IT department then Agile is the wrong way for that department and company.

*sigh* I’ve gone on and on about this and still not got to my own main point, which is this.

- Can we identify reasons for Agile and XP Failing.
- Having identified the Reasons, can we fix them in simple ways?
- Can we create some simple guidelines as to when a project should be more Agile and when it should be more Up-Front design.

I’d love to know people’s opinions on those three points above.