A very long hiatus

It has been 10 months I haven’t made a new post on this blog. My life has taken quite a turn since October last year. I started a new job that involves more than just DBA work, but also managing IBM AIX systems. It’s production support work as well as project work, so it can get a bit tough going with the shift work and on-call duties. Blah! it’s all about challenges in life!

There’s been so much to do in this job, the majority of my time is spent on performance tuning on the data-warehouse and Informatica jobs running their ETL load. I have built up an Oracle Enterprise Manager Grid Control 10g infrastructure, but I want to move onto 11g soon. Right now, I am working on a project to upgrade our databases to 10g and 11g, and finding SQL Tuning Sets very useful. I also got to had a look into Real Application Testing.

It has been a great learning curve on this new job, and I am not finding time to read and write blogs as I used to. Maybe I will settle down soon, so hopefully, I will get back into blogging.

Interesting Graphs

A few weeks ago, one of the testers performed a load test on one of our pre-production environment, and emailed his results in an Excel spreadsheets.

Below are some of the graphs produced:

Figure 1

Figure 2

How to disagree

http://www.paulgraham.com/disagree.html

This is just gold!

Funny material to read on a Friday afternoon… Let me think if I had an DHn thrown at me in the past…

DH0. Name-calling – nope… nobody has called me a fag yet… or maybe they have without saying aloud.

DH1. Ad Hominem – yes… I had my business-related input dismissed before because I am just a developer. I haven’t yet had my technical input dismissed for being a DBA or maybe I am just lucky. I did get my input disagreed for being an inexperience DBA or being new in the company for not knowing the *process*.

DH2. Responding to Tone – I think this level applies when I don’t sound confident or slightly hesitant when I open my mouth or having English rolling out a bit rough out of my mouth, and get dismissed for not knowing what I am talking about.

Sometimes, I get dismissed even if I don’t open my mouth. It’s often not my fault if you reject my opinion for being too quiet. I only open my mouth if I have important things to say or if I am knowledgeable about the topic.

DH3. Contradiction – Now we are getting somewhere. I get this type of disagreement *a lot*. Take a read at CrazyDBA’s story. I like to think that DBA is a very precise business. We don’t start making conclusions unless we know all the facts. Our customers however, may not. I find myself always have to distinguish whether a customer is telling me a fact or interpretation of a fact. When you tell us you know something, we got to either prove it is true, or refute it is not true with evidence.

An interpretation of a fact might be “I can’t access the database. Is the database up?” – “what’s the error message you are getting?” – “ORA-01017: invalid username/password.”. The contradictious argument might be “It was working before…”.

I had customers telling me he’s dead certain he knows the cause of problem because I cannot prove that’s not the root cause due the limitation of my Oracle skills or the lack of time.

DH4/DH5/DH6 – Counter-argument / Refutation / Refuting the Central Point.

I would like to add: Silence. It is also a form of disagreement.

Life as a PhD student…

I am not a PhD and don’t plan on becoming one. My partner is a PhD student. We’ve been together for more than 5 years, of which she’s been a PhD student for 4 years. Walking that journey together is quite gruesome. To keep herself amused, she likes reading the PhD Comics, and I have started reading it too. We both agreed that almost every story is sadly… very true.

If you ever wonder what it is like being a PhD student, take a look at the comics to get a taste…

Melbourne Foods

My girlfriend and I often go to Melbourne for a short weekend break. We simply love the (nice and cheap) food down there, here’s a few places we just keep going back again and again…

The Pho at Mekong – 241 Swanston Street Melbourne

The pasta and pizzas at La Porchetta – 308 Victoria Street, North Melbourne

The mocha at Koko Black – Shop 4 Royal Arcade, 335 Bourke Street Melbourne or the Lygon Street.

The cakes at Cafe Baci’s Crown Casino.

The Vietnamese pancakes at Thanh Ha – Shop 172 Victoria Street (Corner of Lithgow Street) Richmond. This one a local friend brought me there 🙂

The gelato at Limonetto – NewQuay Docklands. Try the Ferrero Roche Gelato!

iPod Touch

I am now a proud owner of the iPod touch – a birthday present from my girlfriend!!

I love my new toy, I haven’t been able to keep my hands off it since Day 1. Of course, you might already have read all about its features, other people’s impression of it, or even seen a real life demo. Though, after playing with it for a week, I would like to blog about what I think about it.

None of these issues are major bad points about the iPod touch, but they are just some of things you might not notice until you have used it for a while.

Good Points (EVERYTHING – but the highlights for me):

1. the Album cover flow – it just makes me want to scroll back and forth all day long. 

2. the automatic tilt/rotate view when I physically rotate the iPod.

3. the touchscreen user interface – it is quite accurate given the width of a finger.

4. the applications – Safari, YouTube, Photo, Video, iTune Store.

5. the Wifi!

6. the screen is very impressive and high resolution – 480-by-320-pixel resolution at 163 pixels per inch. Videos look good on it – try the Starcraft II iPod version trailer!!

7. the clock! it should really be in the list of applications above, but it’s so cool that I should mention it especially. I can keep times of several world cities of my choice, and concurrently, how cool is that? Good for your scheduling of conference calls if people are scattered around the world.

8. the interface is really fast and responsive, unlike some of the mobile phones I used.

9. Support different languages – Big5 characters are displaying fine.

“Other things I noticed”:

1. Battery – the spec says 22 hrs audio playback; 5 hrs video playback. I guess the 22 hrs audio is true if I turned off the screen. If I started playing with album cover flow, change songs/albums… etc. The battery life will be a lot less. For example, I kept the screen on most of the time, and played around with the album cover flow, the battery went down to 20% in about 6-7 hours. At 20%, iPod gave a low battery notification.

2. Wifi – for some reason, the wifi connection wasn’t as fast and stable as I expected, and that’s even placing the iPod next to my wireless router. Can possibly blame the wifi interference, but my laptop or computer has no trouble achieving the full speed of my Internet connection. Maybe it’s just because the iPod is a low-powered device.

3. Touchscreen keyboard – it is nice to use the touchscreen to scroll or drag, but when it comes to typing, I am finding it difficult not to make a typo. It’s very easy to touch the key next to the key you actually want to press. Making a mistake is not so much a problem with normal text fields, but try the masked password field in the Wifi connection, and a 128bit Hex key. I had to do it 5 times before I got it right.

4. Album cover flow – the album images are sharpened when they are brought to the center of the iPod screen. At times, I find the images weren’t sharpened and just remain blur. Just a software refinement I guess.

5. Video – avi or mpg won’t work on the iPod but I guess this is already a known fact. Must use mp4. The Apple website provides some Games or Video trailers in iPod version – they work charmingly, otherwise, you need an mp4/m4v converter.

6. Touchscreen music player – at times, I want to turn down the volume real fast – can’t do that if the iPod screen locks after a max-time of 5 mins (or I can customize it to Never – then the battery will go down even faster). I tried tapping the volume bar real fast once, and accidentally turned the volume to max – hurts the eardrums… duh! (or maybe the pause button is too close to the volume bar in terms of finger width)

7. Albums display – in the normal standup mode, I can scroll the albums list for decide which one I want to play, if I tap on an album once, I see the songs in that album. If I tap the “Albums” icon again, I am brought back to the albums list. The only thing I didn’t like is, I would lose my scroll position unlike what I can get in Internet Explorer’s “Back” button.

8. Finger marks – always use the iPod with clean fingers and clean it regularly to keep it looking as good as new.

All in all, I think it is worth every dollar spent. The iPhone and future iPod Touch can only get better. The size of the screen is not bad for 3G content. One of the things I don’t like about the current 3G phones, is the small screen. I don’t like using a small screen to watch IPTV, browse the web, or using the buttons to control my applications – there’s just too many clicks, layers of menus and it gets too tedious.

Browsing the web on the iPod I felt is actually okay. I am impressed and happy. I can zoom out and zoom in a webpage using my finger gestures.

The only thing to think about is how long will the battery last.

Beyond a DBA…

Ever since becoming an Oracle DBA late last year, it has been a constant quest to understand what truly is a DBA. It is not that I do not know what I am doing or what’s required for my job, but to truly appreciate the many facets might take some time for a newcomer:

• what a DBA does, the skillsets and traits, roles and responsibilities
• where they sit in the organization,
• how to work with different departments
• career path, progression
• the technology itself – 9i, 10g, 11g….
• tools and processes
• many more…

Mike Ault wrote an article on How to be hired as DBA, and briefly, he summarizes DBA knowledge into categories:

• Installation
• Configuration Management
• Security
• Monitoring and Tuning
• Backup and Recovery
• Troubleshooting
• Vendor Interface

He also listed the desired traits of a DBA, which I won’t repeat here. I like his expression of “database baby-sitter” and “full-charged DBA”. The article was written in 1997 (as dated in the Microsoft doc).

Craig Mullins also wrote an article on What is a DBA? He summaries the types of DBAs into:

• System DBA
• Database Architect
• Database Analyst
• Data Modeler
• Application DBA
• Task-oriented DBA
• Performance Analyst
• Data Warehouse Administrator

The article looks to be written in 2002. I believe these types take different specialization into the different database knowledge such as those mentioned by Mike. Craig explains what each types of DBA focuses on in his article nevertheless.

John Bostick has written a recent article titled DBAs fishing for an elevated role. John suggests the many tasks a DBA performs regularly are operational roles. It doesn’t seems as though John draws distinction between the different types of DBA such as those put forward by Craig.

Roles such as Database Architect, Data Modeler or Data Warehouse Administrator are beyond operations. DA and DM are roles that work closely with the development team, offering in-depth database knowledge and best practices.

However, I like what John proposes at the ending paragraphs, to paraphrase –

“… DBAs have a chance to take on a more strategic role within the organization…”, 

“… determine which of this data is most important to the business and how to extract it in a way that is actionable…”

“… turning the data into information that helps move the sales needle…”

“Pooling and parsing the data to show patterns and trends that help the organization make critical decisions…”

Although John did not give a name for this role, it sounds somewhat closely related to what (Craig describes as) a Data Warehouse Administrator (DWA) does. The small difference lies in that a DWA “monitors and supports” the data warehouse environment – database design, ETL, data quality, data formats, interface with BI tools… etc. Whilst John’s idea is for a DBA to turn the data into information to add value the business.

An experienced DBA understands the database technologies available,  understand data models/schemas/metadata, understands and can improve database performance, perform query tuning… etc. It would be a lot more interesting to be a DBA that combine these technical knowledge/skills with soft/business skills, and explore the realm of Business Intelligence, Data Warehouse, Data Mining… etc.

I like where that’s heading and it’s definitely an interesting career path to follow…

[edit] Also found an article written by Doug Burns on “What use is a Development DBA?”. Similar if not the same as the Application DBA Craig wrote about.

My New Rig

For some reason, some people call their computer *rigs*… so I am going to tell you what’s in my new rig. 😀

I put together my new computer a couple of months ago, but I thought I wouldn’t blog about it until I get some benchmarks… turns out I am more lazy than I thought and have delayed until now… so I thought I would write this without benchmarks.

CPU – Intel E6420

I don’t know why spent more money to get the 6420, could have spent less to get a 6320 and get a same deal – overclock to 3GHz. Both are 4MB cache.

Motherboard – Gigabyte GA-965P-DS4

DS4 and DS3P is very similar but DS4 cost more. MSY ran out of stock and I wasn’t willing to wait…. Wasn’t prepared to step up to P35 boards as at the time, they only started to come out, I liked the more matured boards that has bug fixes fixed in revisions.

DS4 only has 1x IDE port, I was trying to reuse my IDE Optical drives and 2x IDE drives from my old computer. A normal IDE cable has 2 sockets for 2 IDE devices, but in reality, the cable wasn’t long enough for me to connect both a IDE HDD and a IDE optical drive.

Buying an extra PCI-IDE card cost money, might as well buy one more SATAII HDD and give the IDE drive to someone else.

Disk Drive – Seagate SATAII 320GB

Not much to say here – Seagate is the brand of choice for me.

Memory – OCZ 2GB-800 DDR2 Kit

Come on… you know you want it! *evil*. I am not running Vista yet.

Graphics Card – Gigabyte 320MB 8800 GTS

This one took me the longest time to decide. This card is the first card that’s coming out that supports DX10, and the price to pay is steep ($400-$500). One model down is the 8600, but if you take a look at various reviews e.g. tomshardware, you will find the 8600 is performing worse than the 7900. So the question comes down to 1). how much can you pay 2). what does DX10 entry level support mean for you. 3). your bragging rights…

After using this new computer for a while, the graphics card is the noisiest component. I have chosen other components based on low noice, except this one I have no control over.

When warranty is over, I might get a Thermalright HR03 Plus… Time will tell how noisy it will eventually get when summer comes. I might also give RivaTuner a go…

Case – Cooler Master Centurion 534 RC-534-KKN2

Good cheap case without power supply. Very good construction, fans at the front and back, plus one on the side panel for the graphics card… but I chose to not use the side fan.

Power Supply –  Seasonic S12-430

This one I am proud of… it was a toss up between Seasonic and Zalman ZM460-APS. Nobody was stocking the Zalman when I was trying to gather the parts, so I went for the Seasonic. The one I got had sleeved cables and it is quiet [silentpcreview]

Case Fan – Noctua NF-S12-1200

I wanted to use my own case fan – quiet, silent and moves good amount of air to keep my case inside cool. So I used silentpcreview.com recommendation. I used the extra adapter to lower the fan speed and used the rubber thumb screws instead of metal screws for noise dampening. Look online to see how it is installed, I found it hard to install the rubber screws, but it is good once it’s in.

Mouse – Razer DeathAdder + eXactMat + Armadillo

I bought a Wireless Logitech MX110 and the charger died after less than 6 months. I didn’t have warranty on it since I bought it from HK. I hate mouse that needs recharging and/or batteries. Period. What’s more annoying than during a game, your mouse is dead!?

Off I go shopping for a wired gaming mouse. Razer came highly recommended by several internet reviews, so I gave it a go… well… at the same time, I also bought the eXactMat and Armadillo.

The mouse itself is nice, but it consumes some CPU when I was testing it on my Centrino laptop (open Task Manager and move your mouse, you will see some CPU spikes). Maybe that’s normal… but the jump is not noticeable with my other M$ Wireless IntelliMouse. The mouse itself is great, read reviews if you want to know how well it performs. I noticed some dust do get inside the mouse after awhile and is hard to clean – the gap between the when you rest your palm and the base of the mouse.

The mat itself is good and wide… but a bit too wide for my desk, so I ended up placing it sideways. I am not a hardcore gamer, so the dual surfaces doesn’t mean much to me, but I got it because I was sick of foam mats.

The armadillo is interesting, it acts as a rest for the mouse cable. The mouse cable is actually quite long, and the weight can sometimes drag and inhibit movements of the mouse. The armadillo is there to stop the dragging. It’s good in general but some times I find the cable were pushing against the armadillo when I move it up and down.

Extra cooling

I might get a Scythe Kama Bay [ocmodshop] at some stage… the basic idea is to keep air intake from the front of the case, and out the back exhaust fan (which I have a Noctua), keeping the air around graphics card and CPU cool. Will see how it goes in summer… I don’t want either the CPU heatsink fan or the graphics card fan to spin up.

New Weblog

Fed up with the Blogspot HTML editor and their themes.

See if this is any better.

Doors

I was driving home around 9pm, and stopped at a traffic light in front of a shopping centre. It was after-hours, and the automated doors were locked. On either side of the automated doors were manual doors.

At that moment, I saw was an elderly couple pushing open the manual doors on the right side to get out. I also saw a younger couple standing in front of the automated doors and found it was locked.

The lady of the younger couple pointed to her partner indicating the right manual door works and they should follow the elderly couple to exit. The partner half-ignoring, walked to the left manual door and pushed it open. The lady then followed.

It was interesting how the younger couple went about the problem – “to find an exit”. I can somewhat relate to how the couple thinks because I think like that guy. The lady saw a working exit. What is more interesting to me was what the guy was thinking at the time – motivated by curiosity or ego – to try the other door.

Curiosity – if the right door works, would the left door work as well? What have we learnt if the curiosity has or has not paid off? Why has the security only left one manual door unlocked or has he left both manual doors opened? What is the cost of making the wrong decision?

Ego – to demonstrate to his partner, that he too can find a working exit. At the same time, risk offending his partner when refusing to listen to her suggestion and being stubborn.

What was obvious to me, was the guy was taking a risk by opting to try the left door. If it doesn’t work, then both himself and his partner would have to walk to the right door to exit.

In a more day-to-day situation, when faced with two alternatives to a problem, and one of them obviously is a working solution, which one would you go for? If you know one alternative works, what are the chances that the other alternative will also work? What would influence you to try the unknown alternative? the pay-off, the risk? how many things goes through your mind before making a decision?

This reminds me of the Monty Hall Problem (obviously, the problem mentioned here is totally different).