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Updated: 6 hours 17 min ago

OOW 2014: Day 2

Wed, 2014-10-08 03:02
Having been awake for so many hours, I was along at Oak Table World bright and early because :-
1) I wanted to make damn sure I got one of the T-shirts. The courier had let down poor Kyle Hailey so they weren't there at first, but I accosted him to remind him that I was one of the first group of people there ;-) (Oh, and it worked later when they turned up.)
2) Because Mogens Norgaard was on first with a 30 minute opening talk. Mmmm, at 08:30? Who came up with *that* moment of scheduling genius?! LOL ... Sure enough, Kyle had to implement a last-minute schedule change and Riyaj Shamsudeen helped out by stepping up to deliver his 9:00 slot 30 minutes early. 
Which was a shame for those who showed up at 09:00 and missed the first half of his In-memory Internals presentation, which I loved. Riyaj always works at a deep level but in those areas that are practically important, rather than just showing off his smarts!

I picked up a few extremely useful things from this presentation but I think the most important one was the journaling area used when rows in the standard row-orientated buffer cache have been updated. Which, for starters, means that only 80% of the allocated memory will be available for your original data. Not a problem, but worth knowing.

What really jumped out at me though was when he discussed how the number of updated rows could affect the optimiser's decision to use In-Memory or not. I might not have explained that very well, but I believe the effect would be that the optimiser is likely to flip between using In-Memory or not depending on quite a few variables. Which means one thing to me. Potential Execution Plan instability. I'm not sure how Oracle could get around this because cost-based decisions are the sensible approach but I foresee lots of new performance analysis and tuning opportunities! Not quite "flick a switch and it just works", but who would ever believe that kind of thing anyway?

Great presentation, though. Exactly what Oak Table World is all about so thanks to Kyle Hailey and the various sponsors () and speakers for making it happen!
When Mogens eventually showed up, he was on top form for his enormously entertaining Conference Opening where he delved into that new Big Data thingy. The strange thing about his presentations is that although they're very quotable, I always find I've been enjoying it too much to remember a damn thing he said! LOL But I managed to have many interesting talks with him later in the week about how unstoppable this Big Data thing is for those who need it. You could question who really needs it, but I personally remember the days of 'why would anyone need their own personal computer' too.
Next up was Andy Mendelsohn's Database General Session in an extremely frosty Marriot. I've become more of a fan of air-conditioning over the past 3 months but this was ridiculous! The presentation was very cloudy at first, then came the In-Memory stuff including Maria Colgan giving the cool demo which I've seen before but seems to have been polished up. The other thing that struck me for the first time in this presentation was just how much better Oracle's new slide template is! As anyone who has used it would confirm, the old one was *very* red and blocky and intense and the new one is so much cleaner and spacious and uses colours that don't kill your eyes. I thought the difference was staggering and actually found myself wanting to look at them for a change! ;-) But, on the whole, it was a relatively sober and honest presentation without any great announcements, but plenty of focus on delivering the meat of the previous year's announcements.

Judge for yourself. No need to go to San Francisco!
Then I was straight over to the first Real World Performance group presentation with Andy Holdsworth and Graham Wood talking about some of the higher level application design issues they have discovered via AWR reports. But first they kicked off with their usual dose of performance analysis and design reality, reflecting on the daft way that customers approach performance (and those last word are mine, based on my own experiences). 
They talked about the obsession people seem to have with identifying and treating narrow symptoms of problems that are, in reality, application design problems that need to be treated from the top down in order to relieve the low-level symptoms.
For example, right at the top of the report is the number of sessions. Imagine 3,300 sessions on a 32 core server. Well you don't need to because this was an AWR report from a real system so no imagination is necessary. Does that make any sense to anyone? Then why do we still see that kind of thing all the time? 

... or how about finding open_cursors set to 2000? A per-session limit of 2000 cursors? As Graham pointed out - good luck keeping track of the state of all of those! As soon as you stop and think about these things sensibly, you realise that it's almost certainly a sign of an application leaking cursors. 

There were lots of similar examples but the interesting overall approach that I would say they were illustrating is something that I tend to do when I first arrive at a new client site and I've watched other experienced Oracle techies do the same.

An AWR report is not just the top 5 timed events and the sections at the top are a pretty good description of the actual system workload which, in turn, can tell you a lot about the application design. Then, based on potential application design issues, you can drill down into the report and look at later sections to see where all those leaked cursors or transaction rollbacks or (whatever) ... are coming from.

Updated Later: As Toon Koppelaars highlighted on Twitter later, you can see this version of exactly what I'm talking about here, for free. I should hang my head in shame because Andrew and Graham made a point of all the RWP videos being available online here. Watch and enjoy!

Lucky boy that I am, I was able to retire to the comforting surroundings of the Thirsty Bear to continue the conversation about all things performance related with Graham and JB, much of the conversation being me whining about why people don't use the *full* range of tools that come with the Diagnostics and Tuning Packs that they've paid Oracle good money for. That's why I've been slowly developing a presentation on that very subject. 

Then it was back to Oak Table World to catch Greg Rahn talking about all that Hadoop stuff *again*! :-) Even though I only caught part of the presentation, I do keep managing to pick up bits and pieces on the subject although I wonder when it'll become relevant to my day to day work. Probably whenever I'm too late to the party, as usual ;-)

But my main reason for showing up was to see Kevin Closson talking about using SLOB in some less obvious ways. Because SLOB is a good all-round Oracle workload generator, it shouldn't be seen as simply a tool for testing storage performance and that's probably it's main strength. Kevin is always a great speaker and I find listening to him a very different experience to reading his blog, but I'm not sure I can put my finger on why. Oh, he also had the most ridiculously bright SLOB buttons! (As I found out by making the mistake of looking to closely at it as I tried to switch it on ;-))

At some point, all of the slides for the Oak Table World presentations should be available on the site, so keep a look out for those! (Oh, and I got my T-shirt which is deeply cool and was one of the few items of non-ACE swag I managed to pick up all week)

From there on, it was more or less party all the way.

- First quiet beers and snacks with lots of Oak Table and Oracle types.

- Then my very first ever Customer event that wasn't for a specific technology area, but a sales region. Man, *that* was a mistake! Suits *everywhere*! ;-) but I suppose it was useful to build contacts with the senior support managers in my new region. 

- Instead, I headed towards the OTN night in Howard Street (until I realised I'd just dropped my bag with the entry ticket back at my hotel room)

- So instead I landed at one of the events of this and any other OOW - The Friends of Pythian Party'. As always, beautifully-organised, very generous on the liquid refreshments and the coolest crowd in town. Just because I find myself thanking Vanessa Simmons, Paul Vallee and all of the Pythian crew every year doesn't make it any less sincere.

I have to be honest, though, and say that the highlight of the night for me was spending much more time with Kevin's punchy, beautiful and fun wife Lori. If you think Kevin's smart, wait until you meet his wife! There's a lady who can hold her own and make me chuckle :-) Problem is that I think she's used to scaring people but us Scots don't scare so easily ;-)

It was a great night anyway, as always, and although this is entirely unconnected to the Pythian party but might have had a *lot* to do with jet lag, I didn't wake up until 11:45 the next morning :-(

OOW 2014: Day 1

Sat, 2014-10-04 23:26
Disclosure: I'm attending Openworld at the invitation of the OTN ACE Director program who are paying for my flights, hotel and conference fee. My employer has helpfully let me attend on work time, as well as sending other team mates because they recognise the educational value of attending. Despite that, all of the opinions expressed in these posts are, as usual, all my own.
After the very welcome tradition of breakfast at Lori's Diner, I had time to register and then get myself down to Moscone South for my first session of the day. I'd planned to listen to Paul Vallee's security talk because I'd been unable to register for Gwen Shapira's Analyzing Twitter data with Hadoop session but noticed spare seats as I passed the room, so switched. I love listening to Gwen talk on any subject because her enthusiasm is contagious. A few of the demos went a little wrong but I still got a nice overview of the various components of a Hadoop solution (which is an area I've never really looked at much) so the session flew by. Good stuff.
Next up was Yet-another-Oracle-ACE-Director Arup Nanda's presentation on Demystifying Cache Buffer Chains. The main reason I attended was to see how he presented the subject and wasn't expecting to learn too much but it's an important subject, particularly now I'm working with RAC more often and consolidated environments. CBC latch waits are on my radar once more!
Next up was 12 things about 12c, a session of 12 speakers given 5 minutes to talk about, well, 12c stuff. Debra Lilley organised this and despite all her concerns that she'd expressed leading up to it, it went very smoothly, so hats off to Debra and to the speakers for behaving themselves with the timing! I was particularly concerned that we kicked off with Jonathan Lewis ;-) Big problem with putting him on first - will he actually be able to stay within the time constraints? Because he'll get too excited and want to talk about things in more depth. He did do it, but it was tough as he raced towards the finishing line ;-)
The only thing that bugged me about this was that I hadn't realised it was two session slots (makes complete sense if I'd performed some simple maths!) but it was very annoying when they kicked everyone out of the room at half-time before readmitting them. Yes, there are rules, but this was one of the more stupid. It annoyed me enough that I decided to skip the second half and attend the Enkitec panel session instead.
What an amazing line-up of Exadata geek talent they had on one stage for Expert Oracle Exadata: Then and Now ....
Enkitec Panel

Including most of the authors of the original book as well as the authors who are writing the next edition which should be out before the end of the year.

From left-to-right : Karl Arao, Martin Bach, Kerry Osborne, Andy Colvin, Tanel Poder and Frits Hoogland.

They talked a little about the original version of the book (largely based on V2) and how far Exadata had come since then, but it was a pretty open session with questions shooting around all over the place and great fun. Nice way for me to wrap up my user group conference activities for the day and head out into the sun for Larry's Opening Keynote. 
First we had the traditional vendor blah-blah-blah about stuff I couldn't care less about but, in shocking news, I actually enjoyed it! Maybe it's because it was Intel and so I'm probably more interested in what they're doing, but it was pretty ok stuff. All the keynotes are available online here.
Then it was LarryTime. Seemed on pretty good form by recent standards although I can summarise it simply as Cloud, Cloud and more Cloud. There's no getting away from the fact that it's been quite the about-turn from him in his attitude towards the Cloud. I did appreciate the "we're only just getting started" message and I suppose I've become innured to how accurate the actual facts are in his presentations and to the attacks on competitors so I sort of enjoy his keynotes more than most.
At this stage, the jetlag was biting *hard* and I ended up missing yet another ACE dinner but from all the reports I heard it was the best ever by some distance so I was gutted to miss out on it. But when you're body is saying sleep whilst you're walking, sometimes you have to listen to it! Then again, when it decides to wake you up again at 2:30, perhaps you should tell it to go and take a running jump!

OOW 2014: ACE Director Briefing

Sun, 2014-09-28 05:41

Disclosure: I'm attending Openworld at the invitation of the OTN ACE Director program who are paying for my flights, hotel and conference fee. My employer has helpfully let me attend on work time, as well as sending other team mates because they recognise the educational value of attending. Despite that, all of the opinions expressed in these posts are, as usual, all my own.

The first day of the ACE D briefing was a bit of a wipe-out for me as I had so much catching up on bits and pieces of work and personal email to do, having arrived very late the previous night, although I still managed to spend some valuable time catching up with friends of the Oak and non-Oak variety as well as hearing some useful info from various Product Managers. I was gutted to have missed Thomas Kurian's briefing session because, as I heard later, it was as splendid as usual. I think some of the enjoyment comes from people's fascination with how on top of things he is, talking at all sorts of technical and non-technical levels over a very wide portfolio. That's pretty much how I remember the last few briefings.

Despite the inevitable arrival of jet lag screwing up my sleep, I've been able to enjoy day two much more (once I'd absorbed some light-hearted wind-ups about my disappearing act). Today was always going to be the most enjoyable for me anyway as the agenda was more database-centric.

It kicked off with a session on the current state of play of MySQL which I must admit I've almost forgotten about (conspiracy theorists will enjoy that) but seems to be ticking along quite nicely with incremental performance and functionality improvements although the presenters were keen to point out that MySQLs forte is not it's functionality so much as it's ubiquity in the web area, given it's part of the LAMP stack. Like a lot of the presentations, it might not have been about something I use day to day but was very enjoyable keeping in touch with other technologies.

Next was an informal conversation with Bob Evans, the Chief Communications Officer, which covered a wide variety of subjects with the usual direct and critical approach I've come to expect from the ACE Directors in attendance (you might be surprised!), raising concerns about the interface between Oracle Sales and their shared customers. I was disappointed to hear that there seems to be a pattern of scheduling local sales events at the same time as Oracle ACE tour events. Seems pretty daft to me. (Another one for the conspiracy theorists, I suppose.)

Then Gene Eun gave us an update on the Oracle Database Cloud Service. Although I still feel Oracle are way behind the curve on this, I don't think that necessarily means they can't make up ground, as they have in the past, but I think the most important message for me was a reinforcement of an answer to a question I asked last year. There's no reason why people can't use the same technology to run their own on-premise cloud and, working in Finance as I seem to have done for a while, the most realistic implementations I can imagine are hybrids of onsite and offsite infrastructure to cope with regulatory requirements whilst still gaining the benefits of offsite deployment where that makes most sense.

I didn't spend so much time drinking coffee in the Oracle canteens this year, but I did manage to have an enjoyable catch-up with Uri Shaft, a true development geek who always has interesting thoughts both on those technologies he is or has been involved with, but also other development areas that he has nothing to do with! Never a man short on opinions on software and a truly nice guy. Sadly, the regular JB catch-up no longer exists and that Maria Colgan moves in entirely different circles these days! (That would be a joke, folks, and I'm looking forward to light refreshments and chat when she's in Singapore soon.)

Speaking of Maria, she was part of the presentation team for the two hour Oracle Database Development Update, which is one of the key sessions for most attendees. Penny Avril and Maria Colgan kicked off with an all-too-short session discussing release plans and a little about In-Memory Option but I was left with the feeling that, having put so much work into getting the In-Memory stuff ready, it's now a case of consolidating the work and delivering product. i.e. I didn't notice any earth-shattering announcements in the database area but I suppose last year made up for that!

So most of the session was focused on two non-RDBMS areas. George Lumpkin on documents in the database and JSON stuff which was one of those - interesting but not something I'm likely to work with for a while presentations. 

Dan McLary was almost certainly the speaker of the day as he delved into Oracle's BigData/Hadoop offering in good detail but with passion and a refreshing honesty about where Oracle fit into this field which still managed to be very positive about where Oracle are taking it. As he pointed out, the combination of being able to query anywhere (different data sources and technologies) with the functional richness of Oracle's SQL implementation is likely to be a pretty compelling offering. 

It was an afternoon full of good presenters likely to keep the jet-lagged awake (although both Connor McDonald and I were struggling badly by this stage) like David Peake who covered Apex and a new website - Learning SQL - to help people, erm, learn SQL. I think we'll be hearing more about this in the upcoming week.

Wim Coekaerts is always popular with a small chunk of the ACED crowd and was again with his usual Linux and VM update, an informal conversation delivered without notes or slides which hit mainly on the areas that the attendees wanted to discuss. In a neat piece of agenda symmetry, he pointed out the presence of DTrace probes for MySQL running on OEL, as he discussed in his recent blog post.

By now we were running late and beers were beckoning, so Steve Feuerstein did a great job of just about keeping people going with his discussion of Oracle's attempts to reengage and energise the traditional Oracle SQL and PL/SQL technologies we know and love with a new (and quite possibly younger!) audience - YesSQL! Keep an eye out for what is likely to be a fun and different session with Steven and Tom Kyte and other special guests at 18:30 on Monday in Moscone South 103.

... and with that all wrapped up, it was time for beers and the bus into the city. The hotel check-in wasn't the car crash it usually is, but by the time it was all done and dusted there was just time for a few more drinks and since then it has been sleep, sleep, sleep for me :-(

The usual thanks to the OTN team for putting together a varied and interesting briefing, which must be a really tough task when the Dev folks are all up to their eyebrows preparing for next week. Great work!

I'm hoping just an hour or two more and I'll be bright and breezy for Sunday, the first proper conference day. With my apparently new-found energy and dashing good looks (courtesy of Singapore), I'm expecting the week to be a good one!

Singapore

Thu, 2014-09-25 16:31

Now, *this* is a post I should have written ages ago but somehow (as in most cases these days) Twitter overtook blogging because it is so much easier to write a bunch of tweets on a mobile device of some kind when living normal life than to sit down and write a blog post.

By now, most people I know know that I've moved to Singapore because I've either bombarded them with face-to-face chat leading up to the move, or they've similarly but asynchronously been bombarded by my 140-character diarrhea on Twitter. (If you care about that, I'm trying to do it from @DouglasIBurns.) But, to spare friends who have not had the joys of either experience who I might be seeing for the first time in a while at Openworld, here are a few facts that might make conversations a little less painful ....

- I now live and work in Singapore.

- It's my first job as an employee of a company other than my own for around 22 years. Those who know me well will understand that this fact is the most surprising and scary of all!

- Singapore is fantastic and don't believe a large majority of what you read about it on the Internet. There's usually some truth in there but it's exaggerated, both positively and negatively. If you're expecting some kind of pristine, well-oiled, boring Utopia, then you've got the wrong place. There are definitely elements of that, but I've been smoking my little head off whilst having a relatively cheap cold Tiger beer in less-than-salubrious surroundings. It might be slick and sterile by Asian standards, but it's lively and real enough for me.

- I have DBA privileges back for the first time in a long time and I'm enjoying that immensely. A senior role that gives me scope to actually *do stuff* is more than fine by me!

- I think our original intention in moving was to give it a try for the minimum 1 year that would be required, but probably 2. However, I keep running into people who thought the same and are here 4, 6 or 8 years later. I can understand why.

- Little known fact: I moved to Singapore when I was around 9 months old because my dad was posted here by the Royal Air Force, just as Singapore was becoming an independent country, and left when I was almost 4. So I grew up in Singapore, but remember nothing about it. However, my older family adored it and they're all looking forward to coming back to visit. I still haven't visited our old home yet. I wonder if it will provoke any memories? As my eldest sister pointed out, I celebrated my first birthday in Singapore and (hopefully) I'll celebrate my 50th one here too.

- Despite the move requiring a lot of effort, I feel re-energised by the place and so hopefully I can get back to more blogging again, particularly as I've had 3 months of interesting issues to contend with, although there will be limits on what I can blog about unless I can reproduce some non-specific test cases :-(

- I am *so* pleased that Morten Egan decided to come here too. He's not only a stellar worker, but a pretty top human being too and it's good to have someone around with similar humour and sensibilities. We'll conquer the world together! (actually, that last bit may be a joke)

It's safe to say that it was a great decision to move and thanks to @madsjt and @RCT_Enterprises for taking it on with me! Other than that, no more Singapore chat here. Follow this Twitter account if you care.

OOW 2014: Beginnings

Thu, 2014-09-25 11:15

Disclosure: I'm attending Openworld at the invitation of the OTN ACE Director program who are paying for my flights, hotel and conference fee. My employer has helpfully let me attend on work time, as well as sending other team mates because they recognise the educational value of attending. Despite that, all of the opinions expressed in these posts are, as usual, all my own.

As I'm completely free of any presentation responsibilities this year, I thought I might try a little blogging again and see how I get on. I'm loving my new Lenovo Yoga 2 Pro, which reminds me of a modernised, lighter version of my old Sony (the red one, rather than the monstrosity that I replaced it with) which is much easier to carry around and work with. As I said, I'll see how I get on.

The most obvious difference from a personal perspective this year is that I'm now a full-time employee of a company in Singapore (more on that in a separate post), which means a few changes :-

- A much longer trip out to San Francisco. It's not quite Australian lengths (kudos to all my Aussie mates for doing this time after time) but 24 hours or so door-to-door is still a little more challenging than my usual trip. I really can't complain much, though. The date-line thing and West-East jet lag on the way here is different, but the flights were fine, particularly after Cathay Pacific bumped me up to PE. (Thanks!) I feel great, to be honest, as a few people have noticed. Singapore is definitely good for me.

- I'm being paid while I'm here! Any independent consultant/contractor will know what a huge difference this is making to me, not having to take time off paid work. On the flip-side, I do need to pay a little more attention to presentations that are relevant to my employer. I've also started being invited to more of those jolly events that *real customers* are invited to. It's a bit difficult having to explain to the local sales guys that my dance card at OOW is already rammed as it is, so I'll probably need to at least show face at a couple of them.

The tail-end of the trip - arriving in the USA - was the most painful part as seasoned visitors will be unsurprised to hear which meant that I was up until around 2:30 local time and with having to tie up some loose ends for the office, it's kind of ruined the first day of the ACE D briefing for me. I've still had time for coffees and chat around the Oracle offices though and it's been great to see so many old friends faces again.

Feeding off how refreshed I feel compared to when I'm usually here and the lack of frantic slide-polishing, I'm looking forward to a great conference!

(Man, I *love* this laptop ...) 

Book Review: Expert Consolidation in Oracle Database 12c

Tue, 2014-09-16 00:46

It's fair to declare up front that the author of this book, Martin Bach, is one of my best friends in the Oracle community (even though I haven't known him for that long really) and someone who I truly respect for all sorts of reasons, both professionally and personally. One of the personality traits I think we share is that, if we thought something was truly awful, we might not call it out as such but we would certainly raise an eyebrow, chuckle internally and then have a private conversation later about just how awful it was!

So if this book was awful, I would probably just pretend that I hadn't read it and certainly wouldn't be writing about it! He *might* remain a friend but I might have to look for new friends who didn't write awful books ;-) (I wouldn't tell him that, of course!)

Fortunately, it is far from awful.

Although Martin has previously written great content on the second edition of the RAC book (in fact I think one of our earliest contacts was a quick informal review of the ASM chapter) this really reads like *his* book and his voice runs straight through the middle (and sides) of it, particularly in the the earlier chapters - 1, 3 and 4. Maybe I should actually talk about what I mean by that and what the book is like instead of sucking up to Martin for a moment?

- It reflects what is truly going on in the day-to-day world of Enterprise Database Computing. Which is to say that it reflects business realities of cost savings, increased consolidation and balancing technical possibilities with practical realities. This is important. I remember when I first started out in IT, I think I was technically good, understood computing subjects and could pick up new ones pretty quickly, helped by my prior career as an assembly language developer and yet I didn't have the first idea of what happened in the IT departments of the big companies because I'd never worked in one. It was very frustrating and took me a long time and a bit of luck to get the right job and learn it as I went. If you've never worked in a big bank, for example, Martin explains what is actually going on in those banks right now because he's been there, seen it and done it. (Or at least attempted to do it whilst fighting the usual internal bureaucracy!) If I'd had this book at the start of my career, I would have understood what banks were looking for and the language they were speaking!

- It's current. Although this won't remain true for some sections of the book (things change so fast in Oracle-land), the coverage of 12c is likely to ensure that in practical terms, it will be several years before even the majority of the technical material is out of date, regardless of what Oracle Corp might announce at the next Openworld conference! Enterprises do move forward constantly to maintain continued support (even when they have current versions that just work), but they don't tend to wrap themselves up in new versions of Oracle for a good couple of years.

- It's accomplished and knowledgable without being smug or arrogant. This is a really important part of any book for me and one that I rarely find in the right balance. I want to read books by those who truly know and understand the subject matter, so I'm likely to gravitate towards books written by experts, but the purpose of the book should be to educate me and not to show off the authors knowledge as some precious gift from a far-flung planet! I wrote about this many years ago and the mere tone of some technical books is enough to make me stop reading. Martin doesn't tell you things because he's clever and you're not. He tells you them to help you do your job and to make your life easier by not having to go through the same pains that he probably did at first. But that doesn't mean the book is fluffy and lightweight either!

- As most authors will tell you, the quality of any technical book is largely dependent on the technical reviewer(s) because it's very difficult to spot one's own mistakes at times and I think that any treatment of technical matters benefits from a second opinion. Frits Hoogland might also be a friend but I also know he has the eye for detail and commitment to technical accuracy a book like this demands. I don't think he had much work to do on the descriptive passages (I happen to recognise Martin's stellar command of the English language and style) but I bet he pulled him up on the odd mistake or two ;-)

As seems increasingly the way with anything I write purporting to be a book review, I don't seem to have mentioned much about what is in the book and what it will teach you, but I suppose it's not exactly difficult for you to check those things yourself. When someone writes a book that I enjoyed reading and found myself nodding my head to as much as this one, I think it's worth my time nudging people in the right direction but letting them decide for themselves if it's the right book for them. Recommended, though!


P.S. I should also point out that I have not worked through the examples in the book because I'm in the process of changing my home setup but, when I do, this is the book I'll be turning to as I work my way through 12c installations.

UKOUG 2014 Elections

Sat, 2014-08-16 18:18
I noticed from Debra Lilley's blog post that there are some UKOUG elections at the moment, with voting closing on 1st September 2014.

Although not an active member or supporter of UKOUG any more (at least partly because I'm based in Singapore!), I've had a pretty long association with the user group and a lot of my friends have been involved over the years, so I still take an interest in what's going on there. Even more so this time, because I know two of the candidates pretty well.

Carl Dudley needs no introduction to anyone who has been remotely close to the UK or European OUG scene down the years and is an old mate who has put in a world of time to UKOUG over the years and, as a techie, has always tried to ensure that it remains relevant to all areas of the membership.

Pauline Drummond, on the other hand, will be largely unknown to most of the OUG community as I think she's only been attending events over the past few years. (I maybe be wrong about that as my memory isn't what it was for some reason ;-)) I know Pauline pretty well, though, as she was a manager at Standard Life when I worked there on contracts for several years before moving down to London, including being my direct manager for the last contract there. President Elect seems a pretty senior role within UKOUG but if Pauline applies the same boundless energy and enthusiasm that she always did in the office then I can see her being great at it. She makes me tired just thinking about all of the volunteering and organisation and sport and work stuff she gets through and is very dedicated and focussed to working with others to get things done, which strikes me as just what you need from a president of a user group.

For a change it's not one of my techie mates I'm suggesting would be good for the role of President because it is a role that needs to respect and appeal to the entire membership and the other entities that UKOUG has to deal with, not least Oracle, so you need someone with a broad corporate view. Pauline is an appropriate choice in this case, although I can't help hoping that she doesn't antagonise potential conference presenters as UKOUG seems to have done over recent times!

Regardless, I always hope for the best for UKOUG and my various mates who put a power of work into their volunteering and presenting roles, so hopefully some new voices will be a step in the right direction ....

Get Up Offa That Thing

Tue, 2014-08-05 04:00
No, no, no ... not *that* JB!
As regular readers will know, the JB who tends to get mentioned most often around these parts is John Beresniewicz who, up until recently, worked at Oracle on all the cool OEM Performance Pages and related instrumentation (alongside others, of course, such as Graham Wood, Uri Shaft, Kyle Hailey and probably a cast of thousands for all I know). Over recent years, JB has become a friend and has always posted deeply insightful comments whenever I’ve blogged about DB Time, Top Activity, Load Maps, ASH Analytics or Adaptive Thresholds. There can be few people who understand those subjects as well and he also has a great way of communicating how such powerful tools can be used to actually make things a lot simpler. (Click On The Big Stuff!, to pick one example) There can be a lot of unexpected complexity behind simplicity, believe me ;-)
So when the opportunity comes to learn from the best, I feel it’s only right I share it. The ASH Architecture and Advanced Usage presentation is a collective effort between Graham Wood, Uri Shaft and JB that has been refined over a number of years. This is the version that JB and Graham delivered at the RMOUG Training Days 2014. It’s excellent stuff from some true Oracle Performance experts.
JB might try to play the grumpiest man in California at times but, after all the work he has contributed to improving the performance analysis tools available to jobbing DBAs, I for one hope he sticks around on this Oracle Performance stuff and isn't distracted by Big Data or Anything-as-a-Service because he’d be too much of a loss (although I wouldn't have to listen to his whining so much, so maybe every cloud etc .... ;-))
Anyway – check out the presentation. It’s well worth your time. Better still, give that man a job so he doesn't have too much time on his hands and be reduced to starting to use Social Media!

Enkitec Extreme Exadata Expo 2014

Wed, 2014-07-30 00:12

(Otherwise known as #E42014 to the Twitterati. Note to the casual reader ... like a lot of conference posts, this is more personal diary entry than having any tech content whatsoever. You have been warned.)

Yes, so this post is hopelessly late, but I really have been busy this time!

Although I feel like I've done quite a few presentations over the past year, a lot of them have been at client sites and the conferences have been a little more spaced out so it felt good to be back in the wild a couple of months ago, particularly as it was going to be my last conference before moving to Singapore for work (more on that later). It was supposed to be a packed week with E4 covering the first few days and OUGF the last few days. Happily for me, @HeliFromFinland was good enough to understand that one conference would steal a lot less Singapore preparation time and the refundable travel made it attractive too. Thanks, Heli! (Although when reading the #OUGF14 tweets in between packing, I'm wasn't so sure!)

I was lucky enough to be able to use some frequent flyer miles to upgrade both my flights to DFW, which was nice. But with no slides to work on and with an unusually low desire to watch movies, I mainly ate, read, slept and drank and the flight seemed to zip by. I believe I might have had one cocktail too many so that, by the time Jason Osborne picked me up in his extremely nice sports car, I could barely form a sentence. (I may be exaggerating slightly) I was nursing a Mojito slowly by the time everyone else was ready to meet at the hotel bar. It turned out to be the first of quite a few (no idea how that happened!) and although I was in bed relatively early, I felt like death when I woke up. I think that's the first time that's ever happened.

Sunday was all about registering and getting a nice Enkitec speaker goodie bag before settling in for an afternoon of Tanel Poder presenting on Exadata Internals and Advanced Performance Metrics - two 90 minute sessions - and although he was splendid as usual, I ended up only managing the first couple of hours before I really had to *get some food* and *sleep*. I got the first half done but the second consisted largely of me lying in a hotel room in a zombified state trying to rise myself for the speakers dinner that Enkitec had laid on



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By the time they were done, though, I was able to catch up with them as they returned for a far more sedate last few beers and an early night in bed.

One of the aspects I like most about E4 is that it's available as a webinar for virtual attendees at a reasonable cost and, because it's recorded, I can watch presentations that I might have missed the first time later, when I have some down-time. It means it's much easier to attend for those who can't get travel permission and also that, if you are particularly interested in presentations I just touch on here, anyone can register and see them all for themselves! (and no, I'm not on commission, I just think some of this stuff should have a wider audience than it already has ...)

One of the presentations that you're probably not likely to see at too many other conferences (I'm certainly not familiar with it) was the initial keynote - Exadata: The Untold Story of a Startup within Oracle with Kodi Umamageswaran who is VP Exadata Product Development at Oracle. I know that lining up this particular speaker took a lot of work from the organisers and it was well worth it for some classic keynote stuff. An entertaining and wide-ranging look at the pre-history of Exadata (SAGE) development, some of the key stages since and a look at the most recent developments. I thought it hit just the right level of being technical enough to be entertaining for a tech crowd, but without getting too bogged down in any one area.

Next up was Tom Kyte's keynote, titled What Needs to Change, during which he talked about some of the many changes in performance expectations and system capabilities in the time he's been working with Oracle and a good sprinkling of the content from the Real World Performance Days he does with Andrew Holdsworth and Graham Wood. My favourite bit of this is always when he talks about how 100% CPU usage is a bad idea for an OLTP-type system (essentially a very bad idea for response times) because I've had so many people at customer sites quote me some Tom Kyte thread or another suggesting that 100% CPU usage is a great thing, because you've paid for that capacity after all. Erm, yes, sure it is for some workloads but possibly a more important Tom Kyte quote is ... 'it depends'!

I wanted to attend Exadata Resource Manager Deep Dive by Akshay Shah of Oracle, but felt I needed to skip at least one session to eat something (Fajitas!) and prepare for my own. Having lunch with Cary Millsap, I was surprised to hear that he would be an Enkitec employee from that day (with a nice sideline in books and tools and training too, of course). It strikes me that this is a good move for all concerned. Nobody sane wouldn't want Cary on board and those Accenture people can help sell the Method-R skills into as many customers as possible. Good move by Kerry Osborne, if you ask me.

I always look forward to watching Tyler Muth present and this time it was a continuation of his central areas of interest these days - High Throughput Computing on Exadata - which was a collection of tips and a sense of the approach he takes when working with large ETL processes and the like. Encouragingly for me, they were very similar to some client work I did a year or two ago at a client, presented at last year's OUG Finland conference and it's always good to know you're heading in the right direction. I remember saying I would write some blog posts about that too! Maybe some day ... I could watch Tyler present all day, whether he sticks to his planned ideas or goes a little off-piste because he always has something interesting to say in an entertaining way and feels like a kindred spirit. (With less swearing perhaps! ;-)) One take-away I noticed was that he recommended the ODA sizing document as a nice guide to stop people over-consolidating their workloads. e.g. Do you really want 42 databases on a 8 core server? I think it was the tables in this section that he was talking about.

Next up was my presentation which I think went well from a presentation perspective and contained some hopefully useful real world DBaaS experiences but I think the problem with that particular presentation is that it's not really technical enough on the one hand and on the other I *want* to keep it light. The truth is that I could probably talk sensibly about the subject for three hours so I've walked away thinking about what I didn't say! Still, it wasn't too bad and Martin Bach seemed to like it, which was comforting :-) 

Not too long later, I had somehow been roped into taking part in a Hadoop vs. Oracle Database Panel with my old mate Alex Gorbachev as the moderator and Tanel Poder, Eric Sammer and Kerry Osborne debating the strengths and weaknesses of the two approaches and whether the RDBMS is on it's way out as a useful technology for most data analysis tasks. I must confess I'm not the greatest fan of panel sessions because you can never get into enough detail and argue the case properly but at least not everyone agreed, although that might have been the beer and jetlag combining in my case :-) Eventually we split into two groups to try to illustrate the different design approaches to a problem from an Oracle or a Hadoop perspective, so I roped in an impossibly young and smart backup team of Martin Back and Karl Arao. I probably still managed to talk over them though ;-) I suppose it was all a good bit of knockabout fun and came with a free beer attached, so I mustn't grumble! I guess I walked away still thinking it's horses for courses ...



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That finished off day one nicely for me as I felt I'd both learned a few things and had fun at the same time. The fun is always guaranteed but I rarely learn as much as I do at E4.

The keynote the following morning was probably worth the price of admission alone. The Exadata SmartScan Deep Dive delivered by Roger MacNicol (who is a Consulting Engineer working on Smart Scan at Oracle) was precisely the type of presentation techies are looking for but with the added value that his presentation style and slides are as excellent as his content. It's so long ago now that I'm a bit short on details but plan to watch it again and, if you get a chance to hear Roger speak at a future conference (are you listening UKOUG?) then you should grab it with both hands, feet and whatever else you have at your disposal!

Maria Colgan, on the other hand, was far too busy working on the upcoming launch of Oracle In-Memory or something to bother about actually attending conferences to deliver her keynotes in person! ;-) Which wasn't a big deal for me personally as I've already heard a *lot* about IMO but it was a good opportunity for me to take the p*** out of her on Twitter!

My last full presentation of the day before I had time for a few beers and to head to the airport was Think Exa! with Martin Bach & Frits Hoogland, which was a collection of a handful of subject areas they highlighted as being worth thinking carefully about during initial implementations on Exadata servers. At first I thought Mr. Bach was going to do all the talking, but they did take it in lengthy alternating sections, which worked really well and set me up nicely for a last few beers with Martin, Frits and soon-to-be-Oak-Table-Network-member Alex Fatkulin, who I've known electronically for a while but only get to see at E4.

It's the second time I've been able to attend E4 in person (the other I attended remotely) and it's quickly become one of my favourite conferences. Sure, it's organised by good people doing a great job and some are friends, but I think as well as taking good care of people, Kerry Osborne's contacts within Oracle on top of Enkitec's consultants and customers merge together to help create a truly special agenda. I'd thoroughly recommend attending if you have the opportunity, even virtually.

Thanks again to everyone at Enkitec for another top job organising this thing and for giving me the opportunity for another trip to Dallas!

However, the complete highlight of the conference for me was getting to spend some decent time with a happy and healthy-looking Peter Bach, which amazed me after the health problems he's faced this year. Good to have you back, Peter, and I bet Oracle are glad to have you back working for them too! LOL

Recurring Conversations: AWR Intervals (Part 2)

Thu, 2014-07-24 03:01

(Reminder, just in case we still need it, that the use of features in this post require Diagnostics Pack license.)

Damn me for taking so long to write blog posts these days. By the time I get around to them, certain very knowledgeable people have commented on part 1 and given the game away! ;-)

I finished the last part by suggesting that a narrow AWR interval makes less sense in a post-10g Diagnostics Pack landscape than it used to when we used Statspack.

Why do people argue for a Statspack/AWR interval of 15 or 30 minutes on important systems? Because when they encounter a performance problem that is happening right now or didn’t last for very long in the past, they can drill into a more narrow period of time in an attempt to improve the quality of the data available to them and any analysis based on it. (As an aside, I’m sure most of us have generated additional Statspack/AWR snapshots manually to *really* reduce the time scope to what is happening right now on the system, although this is not very smart if you’re using AWR and Adaptive Thresholds!)

However, there are better tools for the job these days.

If I have a user complaining about system performance then I would ideally want to narrow down the scope of the performance metrics to that user’s activity over the period of time they’re experiencing a slow-down. That can be a little difficult on modern systems that use complex connection pools, though. Which session should I trace? How do I capture what has already happened as well as what’s happening right now? Fortunately, if I’ve already paid for Diagnostics Pack then I have *Active Session History* at my disposal, constantly recording snapshots of information for all active sessions. In which case, why not look at

- The session or sessions of interest (which could also be *all* active sessions if I suspect a system-wide issue)
- For the short period of time I’m interested in
- To see what they’re actually doing

Rather than running a system-wide report for a 15 minute interval that aggregates the data I’m interested in with other irrelevant data? (To say nothing of having to wait for the next AWR snapshot or take a manual one and screwing up the regular AWR intervals ...)

When analysing system performance, it’s important to use the most appropriate tool for the job and, in particular, focus your data collection on what is *relevant to the problem under investigation*. The beauty of ASH is that if I’m not sure what *is* relevant yet, I can start with a wide scope of all sessions to help me find the session or sessions of interest and gradually narrow my focus. It has the history that AWR has, but with finer granularity of scope (whether that be sessions, sql statements, modules, actions or one of the many other ASH dimensions). Better still, if the issue turns out to be one long-running SQL statement, then a SQL Monitoring Active Report probably blows all the other tools out of the water!

With all that capability, why are experienced people still so obsessed with the Top 5 Timed Events section of an AWR report as one of their first points of reference? Is it just because they’ve become attached to it over the years of using Statspack? AWR has it’s uses (see JB’s comments for some thoughts on that and I’ve blogged about it extensively in the past) but analysing specific performance issues on Production databases is not it’s strength. In fact, if we’re going to use AWR, why not just use ADDM and let software perform automatically the same type of analysis most DBAs would do anyway (and in many cases, not as well!)

Remember, there’s a reason behind these Recurring Conversations posts. If I didn’t keep finding myself debating these issues with experienced Oracle techies, I wouldn’t harbour doubts about what seem to be common approaches. In this case, I still think there are far too many people using AWR where ASH or SQL Monitoring are far more appropriate tools. I also think that if we stick with a one hour interval rather than a 15 minute interval, we can retain four times as much *history* in the same space! When it comes to AWR – give me long retention over a shorter interval every time!

P.S. As well as thanking JB for his usual insightful comments, I also want to thank Martin Paul Nash. When I was giving an AWR/ASH presentation at this springs OUGN conference, he noticed the bullet point I had on the slide suggesting that we *shouldn’t* change the AWR interval and asked why. Rather than going into it at the time, I asked him to remind me at the end of the presentation and then because I had no time to answer, I promised I’d be blogging about it that weekend. That was almost 4 months ago! Sigh. But at least I got there in the end! ;-)

Recurring Conversations: AWR Intervals (Part 1)

Mon, 2014-07-07 07:36
I've seen plenty of blog posts and discussions over the years about the need to increase the default AWR retention period beyond the default value of 8 days. Experienced Oracle folk understand how useful it is to have a longer history of performance metrics to cover an entire workload period so that we can, for example, compare the acceptable performance of the last month end batch processes to the living hell of the current month end. You'll often hear a suggested minimum of 35-42 days and I could make good arguments for even more history for trending and capacity management.

That subject has been covered well enough, in my opinion. (To pick one example, this post and it's comments are around 5 years old.)  Diagnostics Pack customers should almost always increase the default AWR retention period for important systems, even allowing for any additional space required in the SYSAUX tablespace.

However, I've found myself talking about the best default AWR snapshot *interval* several times over recent months and years and realising that I'm slightly out of step with the prevailing wisdom on the subject, so let's talk about intervals.

I'll kick off by saying that I think people should stick to the default 1 hour interval, rather than the 15 or 30 minute intervals that most of my peers seem to want. Let me explain why.

Initially I was influenced by some of the performance guys working in Oracle and I remember being surprised by their insistence that one hour is a good interval, which is why they picked it. Hold on, though - doesn't everyone know that a 1 hour AWR report smoothes out detail too much?

Then I got into some discussions about Adaptive Thresholds and it started to make more sense. If you want to compare performance metrics over time and trigger alerts automatically based on apparently unusual performance events or workload profiles, then comparing specific hours today to specific hours a month ago makes more sense than getting down to 15 minute intervals which would be far too sensitive to subtle changes. Adaptive Thresholds would become barking mad if the interval granularity was too fine. But when nobody used Adaptive Thresholds too much even though they seemed like a good idea (sorry JB ;-)) this argument started to make less sense to me.

However, I still think that there are very solid reasons to stick to 1 hour and they make more sense when you understand all of the metrics and analysis tools at your disposal and treat them as a box of tools appropriate to different problems.

Let's go back to why people think that a 1 hour interval is too long. The problem with AWR, Statspack and bstat/estat is that they are system-wide reporting tools that capture the difference (or deltas) between the values of various metrics over a given interval. There are at least a couple of problems with that that come to mind.

1) Although a bit of a simplification, almost all of the metrics are system-wide which makes them a poor data source for analysing an individual users performance experience or an individual batch job because systems generally have a mixture of different activities running concurrently. (Benchmarks and load tests are notable exceptions.)

2) Problem 1 becomes worse when you are looking at *all* of the activity that occurred over a given period of time (the AWR Interval), condensed into a single data set or report. The longer the AWR period you report on, the more useless the data becomes. What use is an AWR report covering a one week period? So much has happened during that time and we might only be interested in what was happening at 2:13 am this morning.

In other words, AWR reports combine a wide activity scope (everything on the system) with a wide time scope (hours or days if generated without thought). Intelligent performance folks reduce the impact of the latter problem by narrowing the time scope and reducing the snapshot interval so that if a problem has just happened or is happening right now, they can focus on the right 15 minutes of activity1.

Which makes complete sense in the Statspack world they grew up in, but makes a lot less sense since Oracle 10g was released in 2004! These days there are probably better tools for what you're trying to achieve.

But, as this post is already getting pretty long, I'll leave that for Part 2.

1The natural endpoint to this narrowing of time scope is when people use tools like Swingbench for load testing and select the option to generate AWR snapshots immediately before and after the test they're running. Any AWR report of that interval will only contain the relevant information if the test is the only thing running on the system. At last year's Openworld, Graham Wood and I also covered the narrowing of the Activity scope by, for example, running the AWR SQL report (awrrpt.sql) to limit the report to a single SQL statement of interest. It's easy for people to forget - it's a *suite* of tools and worth knowing the full range so that you pick the appropriate one for the problem at hand.