In Recovery...

There's another SQL Quiz (from Chris Shaw) doing the rounds where people blog the answer and then tag someone. This I got tagged by two people (Jason Massie and Gail Shaw) in the same day for the same quiz (albeit over a week ago). They either think I'm going to say something profound or funny, or maybe profoundly funny. Can you say something funnily profound? Ah, got it: profound or strange, or strangely profound, or profoundly strange. Whatever. On with quiz. I'll try not to disappoint.

Question 1: Do you feel that you have a reliable SAN Solution? If so what is the secret?

No. Well, that was easy, eh?

Ok, seriously - we don't have a SAN or any production databases per se, as we're a training and consulting company. We do have a lot of storage hardware (3 x DELL MD3000i's packed with 26TB (unformatted)), but it's not managed by a SAN. However, we do have a lot of clients that DO have SANs. So how do we know they have a reliable SAN solution? I guess there are a number of different factors off the top of my head, and I'm not a SAN expert:

Was it designed for the job it's doing?
Are there redundant components to protect against hardware failure?
Was it configured by someone who knows what they're doing, with that brand of SAN?
Was it load tested to ensure it's can handle the job it was designed for? Was SQLIOSim run to simulate overloading the SAN to flush out any issues?
At the time it was configured, was the firmware all up-to-date, with no known bugs? I saw 'at the time it was configured' because you have to be careful about willy-nilly upgrades to firmware in the various components. Someone that doesn't know what they're doing can destabilize a SAN by upgrading a piece of firmware that subtly changes the behavior.
Are page checksums configured on the SQL databases to help detect I/O problems? Are regular consistency checks being run?

I would say that a 'no' answer to any of these is cause for concern.

Question 2: Describe database mirroring in laymen’s terms.

I'll try a few different answers. You be the judge.

1) I could make this very, very simple and just say "It's really technical and you don't want to know". That's not really in the spirit of things though.

2) Imagine 2 seven year-old girls, in separate rooms (like my youngest daughter and one of her friends). Maybe even separate countries. Girl #1 is painting a picture, using the standard easel setup. There's a webcam pointing at the painting that girl #1 is doing. Girl #2 has a monitor and can see what girl #1 is doing. They're also on the phone with each other. Whenever girl #1 paints a brush-stroke, she can't paint any more until girl #2 has made the exact same brush-stroke and said "Done it." That's the synchronous part of mirroring. Girl #1 can't get ahead of girl #2. Asynchronous mirroring is where girl #1 doesn't have to wait for girl #2 to keep up. With a witness, there's a third girl, with two webcams and another phone...

Hmm - ok this analogy isn't working. It seemed so promising! Let's try again...

3) This came to mind after taking a shower this morning in the hotel north of Houston. Database mirroring is like having redundant hot-water heaters. If the hot water fails from one heater, the heat-operated valve flips and the hot water is drawn from the other hot-water heater. You need two hot water heaters, and a fast-operating valve. If the first hot water heater is fixed/warmed up again, you can manually switch the water-flow valve back. If both hot-water heaters are unavailable, no hot water. See, failover clustering won't work, because then you've only got one hot water heater, with redundant pipes coming out of it. And replication won't work because there's a lot of latency between the water leaving the hot water heater and reaching the shower head. Ok - got a bit carried-away there.

Luckily we have a redundant hotel across the street, so if there's no hot water by the time we return from a day of bird-watching on the Gulf Coast, we can move to the redundant hotel. Although that's a lot more hassle, and a lot slower than if this hotel had a redundant hot water heater...

PS Some other folks (that I know of) have replied to the quiz - here are links to their answers:

And you can follow me on Twitter at @PaulRandal

PPS I'm not tagging anyone - been too long since the quiz started I think - the usual suspects have all been tagged already.

Categories:
Database Mirroring | IO Subsystems | Jokes

Saw this on Twitter (anonymous original author):

A SQL query walks into a bar. It goes up to two tables and says "Mind if I JOIN you?"

Categories:
Jokes

Here are a couple of videos I came across today that are very funny. The second one had me in tears laughing. Let's just say that it could easily be Kimberly singing the second one - she'a bit of a toast fanatic.

1) "Cannon PI" - start of a new spoof video series from Microsoft: http://www.youtube.com/watch?v=cCApcSq1ke0

2) "YEAH TOAST" - just go watch it: http://www.youtube.com/watch?v=FaadfxSkDYA

Enjoy!

Categories:
Jokes

This is a hilarious video of what Facebook would be in real-life - well worth a couple of minutes for a lunch-time laugh.

http://www.youtube.com/watch?v=nrlSkU0TFLs

Enjoy!

Categories:
Jokes

On Tuesday I recorded a couple of sessions with Richard and Greg on RunAs Radio. It's been a while since either Kimberly or I have been on the show - last November at TechEd in Barcelona. In the first session we discussed what it is to be an "involuntary DBA" - someone who's thrown into the DBA role with no training. This goes along nicely with the TechNet Magazine article I wrote for the August 2008 issue on Effective Database Maintenance (for the involuntary DBA). Kimberly also pops in from time to time when she's not coughing, we make fun of her, and I describe one of my favorite Calvin and Hobbes cartoons around collecting spit in a jar - all the usual silliness.

The show is 35 minutes long and you can download it at http://www.runasradio.com/default.aspx?showNum=72.

Enjoy!

Categories:
Database Maintenance | Interviews | Jokes | Involuntary DBA

(Redmond, WA: For immediate release worldwide)

Today, in a surprise development that has stunned industry analysts, SQLskills.com announced a new technology for DBAs that will help in the never-ending battle against human-error and unforeseen disasters. The patent-pending Time-Setback technology allows DBAs of SQL Server to literally rewind time and avoid disasters before they happen.

Renowned SQL expert Kimberly Tripp said in an interview earlier today: "This will be a real boost for harried DBAs. All this time I've been going on and on and on about how DBAs should have a comprehensive backup strategy to cope with disasters. Now they can just forget all of that, throw caution to the wind, and rely on a Time-Setback device!"

Asked how the R&D department developed the technology, a spokesman for the company said "We got the idea after reading Harry Potter and The Prisoner of Azkaban, where Hermione is given a Time-Turner device from Professor Dumbledore. We figured there had to be some scientific basis for it, just like all those books that explain how Star Trek and the X-Files are based on real physics too. So, we had a crack at creating it and it worked! I'm not sure the color's quite right though. Maybe we'll change that in V2. Anyway, cool eh?"

A further disclosure, from a major software company, explained that it is in talks with SQLskills.com to purchase almost a thousand of the devices to hand out to developers to "ensure we ship this year and don't have to change the name". The spokesman wouldn't name the product when pressed.

The device will launch on April 1st, 2008, and will be available for immediate delivery. Although the company has only manufactured 4 of the devices, it will use one of them to do just-in-time manufacturing as orders stream in. For further details, please send email to: AprilFools@SQLskills.com

(Redmond, WA: For immediate release worldwide)

Categories:
General | Jokes

Well, I bet that title grabbed a bunch of people's attention :-)

In the Beijing Advanced Research Centre offices of Microsoft where we're teaching this week, the bathroom stalls have print-outs of jokes on them. The ones in the women's bathroom are pretty good - here are a couple of them that made us laugh (thanks to Kimberly for doing the research!)

#1: A man has a girlfriend, Lorraine, who's he's been dating for a while. He's pretty happy. Into his life suddenly comes a new woman, called Clearly, who is better than Lorraine in many ways - she knows the best place in town to visit, to eat, and to dance. Unfortunately he doesn't want to give up on Lorraine though. One day they're walking along the banks of a river when Lorraine falls in and is swept away. The man starts singing 'I can see Clearly now Lorraine has gone...'

#2: A man and his wife are lying in bed, just about to fall asleep. The conversation goes like this:

Wife: 'If I were to die, would you re-marry?'

Husband: 'Of course not!'

Wife: 'Why? Don't you like being married?'

Husband: 'Well, yes - I suppose I would re-marry'

Wife: 'Would you take down all the pictures of me and replace them with her?'

Husband: 'Well yes, that would be the proper thing to do'

Wife: 'Would you let her use my golf-clubs?'

Husband: 'No, she's left handed... oh shit!'

:-)

Categories:
Personal | Jokes

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