Loss Aversion and the Setting of DB_BLOCK_CHECKSUM

Within Accenture Enkitec Group, we have recently been discussing the Oracle db_block_checksum parameter and how difficult it is to get clients to set it to a safer setting.

Clients are always concerned about the performance impact of features like this. Several years ago, I met a lot of people who had—in response to some expensive advice with which I strongly disagreed—turned off redo logging with an underscore parameter. The performance they would get from doing this would set the expectation level in their mind, which would cause them to resist (strenuously!) any notion of switching this [now horribly expensive] logging back on. Of course, it makes you wish that it had never even been a parameter.

I believe that the right analysis is to think clearly about risk. Risk is a non-technical word in most people’s minds, but in finance courses they teach that risk is quantifiable as a probability distribution. For example, you can calculate the probability that a disk will go bad in your system today. For disks, it’s not too difficult, because vendors do those calculations (MTTF) for us. But the probability that you’ll wish you had set db_block_checksum=full yesterday is probably more difficult to compute.

From a psychology perspective, customers would be happier if their systems had db_block_checksum set to full or typical to begin with. Then in response to the question,

“Would you like to remove your safety net in exchange for going between 1% and 10% faster? Here’s the horror you might face if you do it...”

...I’d wager that most people would say no, thank you. They will react emotionally to the idea of their safety net being taken away.

But with the baseline of its being turned off to begin with, the question is,

“Would you like to install a safety net in exchange for slowing your system down between 1% and 10%? Here’s the horror you might face if you don’t...”

...I’d wager that most people would answer no, thank you, even though this verdict is opposite to the one I predicted above. They will react emotionally to the idea of their performance being taken away.

Most people have a strong propensity toward loss aversion. They tend to prefer avoiding losses over acquiring gains. If they already have a safety net, they won’t want to lose it. If they don’t have the safety net they need, they’ll feel averse to losing performance to get one. It ends up being a problem more about psychology than technology.

The only tools I know to help people make the right decision are:

1. Talk to good salespeople about how they overcome the psychology issue. They have to deal with it every day.
2. Give concrete evidence. Compute the probabilities. Tell the stories of how bad it is to have insufficient protection. Explain that any software feature that provides a benefit is going to cost some system capacity (just like a new report, for example), and that this safety feature is worth the cost. Make sure that when you size systems, you include the incremental capacity cost of switching to db_block_checksum=full.

My teammates get it, of course, because they’ve lived the stories, over and over again, in their roles on the corruption team at Oracle Support. You can get it, too, without leaving your keyboard. If you want to see a fantastic and absolutely horrifying short story about what happens if you do not use Oracle’s db_block_checksum feature properly, read David Loinaz’s article now.

When you read David’s article, you are going to see heavy quoting of my post here in his intro. He did that with my full support. (He wrote his article when my article here wasn’t an article yet.) If you feel like you’ve read it before, just keep reading. You really, really need to see what David has written, beginning with the question:

If I’ve never faced a corruption, and I have good backup strategy, my disks are mirrored, and I have a great database backup strategy, then why do I need to set these kinds of parameters that will impact my performance?

Enjoy.

I Wish I Sold More

I flew home yesterday from Karen’s memorial service in Jacksonville, on a connecting flight through Charlotte. When I landed in Charlotte, I walked with all my stuff from my JAX arrival gate (D7) to my DFW departure gate (B15). The walk was more stressful than usual because the airport was so crowded.

The moment I set my stuff down at B15, a passenger with expensive clothes and one of those permanent grins established eye contact, pointed his finger at me, and said, “Are you in First?”

Wai... Wha...?

I said, “No, platinum.” My first instinct was to explain that I had a right to occupy the space in which I was standing. It bothers me that this was my first instinct.

He dropped his pointing finger, and his eyes went no longer interested in me. The big grin diminished slightly.

Soon another guy walked up. Same story: the I’m-your-buddy-because-I’m-pointing-my-finger-at-you thing, and then, “First Class?” This time the answer was yes. “ALRIGHT! WHAT ROW ARE YOU IN?” Row two. “AGH,” like he’d been shot in the shoulder. He holstered his pointer finger, the cheery grin became vaguely menacing, and he resumed his stalking.

One guy who got the “First Class?” question just stared back. So, big-grin guy asked him again, “Are you in First Class?” No answer. Big-grin guy leaned in a little bit and looked him square in the eye. Still no answer. So he leaned back out, laughed uncomfortably, and said half under his breath, “Really?...”

I pieced it together watching this big, loud guy explain to his traveling companions so everybody could hear him, he just wanted to sit in Row 1 with his wife, but he had a seat in Row 2. And of course it will be so much easier to take care of it now than to wait and take care of it when everybody gets on the plane.

Of course.

This is the kind of guy who sells things to people. He has probably sold a lot of things to a lot of people. That’s probably why he and his wife have First Class tickets.

I’ll tell you, though, I had to battle against hoping he’d hit his head and fall down on the jet bridge (I battled coz it’s not nice to hope stuff like that). I would never have said something to him; I didn’t want to be Other Jackass to his Jackass. (Although people might have clapped if I had.)

So there’s this surge of emotions, none of them good, going on in my brain over stupid guy in the airport. Sales reps...

This is why Method R Corporation never had sales reps.

But that’s like saying I’ve seen bad aircraft engines before and so now in my airline, I never use aircraft engines. Alrighty then. In that case, I hope you like gliders. And, hey: gliders are fine if that makes you happy. But a glider can’t get me home from Florida. Or even take off by itself.

I wish I sold more Method R software. But never at the expense of being like the guy at the airport. It seems I’d rather perish than be that guy. This raises an interesting question: is my attitude on this topic just a luxury for me that cheats my family and my employees out of the financial rewards they really deserve? Or do I need to become that guy?

I think the answer is not A or B; it’s C.

There are also good sales people, people who sell a lot of things to a lot of people, who are nothing like the guy at the airport. People like Paul Kenny and the honorable, decent, considerate people I work with now at Accenture Enkitec Group who sell through serving others. There were good people selling software at Hotsos, too, but the circumstances of my departure in 2008 prevented me from working with them. (Yes, I do realize: my circumstances would not have prevented me from working with them if I had been more like the guy at the airport.)

This need for duality—needing both the person who makes the creations and the person who connects those creations to people who will pay for them—is probably the most essential of the founder’s dilemmas. These two people usually have to be two different people. And both need to be Good.

In both senses of the word.