OOW 2014: Day 2

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.

… 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 🙁