Showing posts with label mysql. Show all posts
Showing posts with label mysql. Show all posts

This Week I Learned 2018 - Week 30

Last week post or something random from the past.

Is MySQL an ACID compliant database? On paper yes, but in reality, not quite. For example, database dumping using mysqldump have an issue where did not backup tables with proper single quote escape. This was quite a tricky bug I've encountered where MySQL silently ignore inserting certain records due to quoting issue. Only when certain records were missing from the application, I only realized that database restoration did not work as intended. I wouldn't have figure this out if not for the need of the record. In the end of the day, a workaround was added but unfortunately, wasted a whole day to track this down through numerous dumping and restoring the database.

How do you organize/track your personal goals? Pen and paper, nothing more and nothing less. Write it down and make it happen. Off course, the usual productivity systems like SMART or GTD but to what extend? Sometimes you just need to chill and don't pressure yourself so much.

What is PERMA? Basically this represents an acronym of a theoretical model to achieve well-being or happiness by Martin Seligman in the field of positive psychology. The components of the model are position engagement (there is a difference between pleasure and enjoyment), engagement (in the 'flow', they said), relationships, meaning (doing something other than yourself), and lastly accomplishments. Does the application of this model in online learning platform have an implication on learning ability of these online learners?

What is one anime adaptation worth watching? Monster by Urasawa Naoki. I was quite late to discover this anime but the the style and story line was worth it and way different from the conventional Shōnen manga.

This Week I Learned 2018 - Week 19

Last week post or something else instead.

Surprised and shocked. The only two words I can think off to describe my feeling for the past week. First, surprised because this one particular item on my bucket list which I guestimate will took me next 20-plus years or never to check off have been accomplished this week. Secondly, shocked it came so soon and such a massive shift and the non-stop flair of dramas. The staycation was well-needed as I was still recovering from my injury. Enough said, I've done my part and moved on to next item on my list.

Infestation of the Blue Green Algae (BGA) is getting worse and we have to do almost daily water changes on certain aquarium tanks. Prevention method is quite straightforward, use blackout method. First, 30% to 50% water changes, add air stone, cover tank for 3 to 4 days, and did another 30% to 50% water changes again.

Some MySQL stuff I've encountered recently.

When creating a MySQL stored function, do remember if the function does not modify data, you will need to set extra explicit options for binary logging.
ERROR 1418 (HY000): This function has none of DETERMINISTIC, NO SQL,
or READS SQL DATA in its declaration and binary logging is enabled
(you *might* want to use the less safe log_bin_trust_function_creators

The sample SQL statement as follows.

The limitation or restriction of subquery in MySQL. It doesn't supports `LIMIT` in subquery yet? Encountered this error message. To work around, you've to rewrite you SQL query using `JOIN` instead.
SQL Error (1235): This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery'

Can't delete using subquery? Wrap your subquery in additional subquery.
FROM tableE e
        FROM tableE
        WHERE arg = 1 AND foo = 'bar'
    ) x

This Week I Learned 2018 - Week 14

Something from the archive or last week post.

We have been doing blood pressure measurement wrongly for all this while. You must measure blood pressure from both arms. Yes, both arms and find the differences. According to Harvard Health,
"A blood pressure difference of 10 to 15 points or more between arms also boosted the chances of having a stroke or dying from cardiovascular disease. "
Personal data and GDPR: practical guide for developers. Shaking my head while reading through the whole post. I was wondering how a software team going to ensure data anonymization in development environment when handling production data? When come to this, the US/Canada software houses are doing a better job than the EU/Asia counterpart.

What if we apply this to our life instead? Rearrange your line of thoughts in your writing. Intriguing discussion when come to writing.

"The Surgical Team" (chapter 3 in the infamous book, The Mythical Man-Month), a different software development team structure which it's similar to the surgery team where,
"The idea was to construct development teams in a way similar to the surgery teams - one lead developer, one assistant developer (these two "adult" and very good), and a 3-4 other people who 's job is to make the life easier for the main devs - someone to manage documentation, someone else to do detailed testing, one average dev to do the simple and boring stuff, and so on."
Maybe an alternative approach where the Agile methodology like Kanban or Scrum cannot be applied successfully or productively. Why so? Cargo cult software engineering, as coined by Steve McConnell where software development houses try to imitate successful processes or approaches without understanding why such methodologies works for them. What works well (may due to luck and timing) for an organization or team may not be suitable for another organization or team. Don't uses Scrum for the sake of using Scrum. Another good example, the reinventing of office space, open office, pool table, ping pong table, gaming corners, and the like. Yes, the startups starter pack.

Fork and Pull Request Workflow. While version control system have been available since the 70s, till today, amazingly, some companies still refuse or slow to adopt it. Everyone have their own workflow and branching models.

Quite a number of MySQL Gotchas this week. Fair enough, it will happen to any of the DBMS out there. My tolerance towards MySQL have increased along these years. Must be something to do with getting old.

How do you order a list of items where the NULL data is at the bottom of the list? It's actually quite easy, just use ORDER BY ISNULL. See the example below.
SELECT * FROM table ORDER BY ISNULL(field), field ASC;

NULL, NULL, NULL, 1, 2, 3, 4
1, 2, 3, 4, NULL, NULL, NULL

Creating a function in MySQL. That was rare but somehow we may need it to reduce or shorten the SQL query. Yet, we kept encounter this idiotic error of "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'DELIMITER |' at line 1". Just add a BLOODY space! Yes, a BLOODY space before the semicolon!
Create function or procedure
Write your function or procedure here...
End (without semicolon)
DELIMITER ; (semicolon with space)

Write UPDATE SQL query with multiple joins and SUB-SELECT but the query won't work in SUB-SELECT? Wrap the SUB-SELECT condition with one more join!
DELETE FROM story_category
WHERE category_id NOT IN (
    SELECT cid FROM (
        SELECT DISTINCT AS cid FROM category
        INNER JOIN story_category ON
    ) AS c 

How many ways to insert a not found record in MySQL? Plenty of ways. Not sure these works cross database systems.

Career do-over? Either moving to management and if you don't like it, restart your development career again.

This Week I Learned 2018 - Week 05

Last week post or something from the archive.

New week and we're embracing the second month of 2018. The summer (for Southern Hemisphere, summer starts from December 1 till February 28 or 29) wind was blowing gently indicating the near of Chinese New Year. 活了大半辈子,原来南半球的季节正好跟北半球相反,真的是受教了!俗语说,“一年之计在于春,一日之计在于晨”, 自己要好好检讨及规划!

Going through my daily steps count, less activity this week due to sickness. Icy cold drinks during midnight and middle-age guy don't was not a good combination. But luckily we have long vacation, good to catch up with my needed rest and recovery. Comparison of total steps walked as illustrated below. (Yes I know the missing legend) Target for next week is to average out the steps till 5000 steps and above.

Dropsy and the whole body is pineconing? Nothing much we can do besides except humanely euthanize the fish. We lost three this week and unexpectedly the Blue Mable is going down also. The typical treatment is daily water changes combines with aquarium salt, Methylene blue, or Malachite green. We're not sure but I suspicious was due to overfeeding which leads to stress and constipation as well as infection.

When visited enough Aquarium shops, you will learn a thing or two. First, antibiotic powder (yellowish colour, suspect the main ingredient is Sodium Nifurstyrenate) usage was quite common especially expensive tropical fish like Discus (not a fan and seriously, a moving water pancake?!). Second, fish sellers in Market Road packed their fishes in plastic bags treated green water (suspect is Malachite green) and unpack it again in plastic square tank for selling each water in plain water. You can achieve profit if you can sustain the longevity of the fishes until they are sold to the customer.

More conversations breeders. It seems that female Bettas are far more expensive than male and fellow breeders don't want to sell their precious female Bettas to retain their quality breed of lines. Only for those who have financial gains from doing this. I wish more breeders should focus partially on the locally Malaysian Bettas. There is one breeder and I wish him all the best. Wild Bettas found locally may not be that colourful but it's good to breed and increase the population.

You know the play was so good that even the opposite bench players applauded it. This reminded me of Kobe Bryant's baseline reverse dunks. Along with Giannis AntetokounmpoBen Simmons is another NBA player to watch out for in the coming few years. Only time will tell.

Too many blockchain wannabe tech startups in Malaysia. Enough said. The never ending of startups chasing the next hype cycle.

How do you unstaged changes in Git? There are cases where merging or rebasing kind of messed up and you're left with a list of modified files.
$ git stash save --keep-index --include-untracked

Meanwhile, you can clean up your local working repository in Git through interactive mode or Git clean interactive.
$ git clean -di

The list reduction functions in List::Util. Some good examples:
$foo = reduce { $a > $b ? $a : $b } 1..10       # max
$foo = reduce { $a gt $b ? $a : $b } 'A'..'Z'   # maxstr
$foo = reduce { $a < $b ? $a : $b } 1..10       # min
$foo = reduce { $a lt $b ? $a : $b } 'aa'..'zz' # minstr
$foo = reduce { $a + $b } 1 .. 10               # sum
$foo = reduce { $a . $b } @bar                  # concat

More effed up stuff in our beloved MySQL. This time, "SQL Error (1451): Cannot delete or update a parent row: a foreign key constraint fails ....". To quote from the documentation (emphasis added),
If ON UPDATE CASCADE or ON UPDATE SET NULL recurses to update the same table it has previously updated during the cascade, it acts like RESTRICT. This means that you cannot use self-referential ON UPDATE CASCADE or ON UPDATE SET NULL operations. This is to prevent infinite loops resulting from cascaded updates. A self-referential ON DELETE SET NULL, on the other hand, is possible, as is a self-referential ON DELETE CASCADE. Cascading operations may not be nested more than 15 levels deep.

In other words, self-referenced foreign key(s) or recursive deletes doesn't work in MySQL (it WORKS in a PROPER database management system like PostgreSQL). You have to create another new table to link the relationship, something like many-to-many data model. If you needs deep nested hierarchy data structure, use Closure Table.

This Week I Learned 2018 - Week 03

Last week stuff and all the archive posts.

大水冲了龙王庙 (一家人不认一家人)。看了几套大陆片,一直听到这句歇後語(英文应该是Idiom吧?)非常适合那些说话不直截了当,话中有话的人。另外还有几句普遍的,例如:
  • 有事鍾無艷,無事夏迎春
  • 豬八戒照鏡子(裏外不是人)
  • 秀才遇到兵(有理說不清)
  • 無事獻殷勤 (非奸即盜)
  • 泥菩薩過江(自身難保)
  • 快刀斬亂麻 (乾淨俐落)

Chinese New Year is around the corner, surprisingly this year, the weather is getting colder and not warmer especially after the Dongzhi festival. Several fishes have died due to infection and we suspected that tank contamination from other fishes without quarantine and cold weather may be the root cause. Water parameters are a dead and life issue for these fishes.

All the Bettas have been quarantines and water changes done on almost daily basis. Some of them are recovering and seems more active. We have change our approach to water changes and sea salt, which are good practices to keep the fishes healthy. Unless necessary, no more chemical like Malachine Green (debatable toxicity issue, it can kill both bacteria or fishes). Methylene Blue or Formaldehyde (aka Formalin) are still safe to use. Even so, each antimicrobials have their own safety issue and met with apprehension issue in the fishing industry, especially aquaculture (fishes breed for eating). Aquarium medication is an interesting area for investigating. Expect more future discussions on this.

Overfed your fishes? Expect bloating and constipation issue to follow suit. Nothing but pea to help them with their digestion. Surprisingly these fishes crave pea. Well, pea should be on their weekly diet then.

cron.weekly is no more. It's not easy to continuously writing up and weekly aggregate posts. Definitely you're going to burn out somehow or another. I've tried different approach and the only possible way is to do it on daily basis, sit down in front of you computer for 15 minutes and write something up. Consistency is the key here, whether you like it or not.

Cal Newport have a good write-up on digital de-cluttering. Find and cultivate high-quality leisure instead of instant gratification low-quality digital distractions (news feeds, social media posts, or videos). A deliberated and strategic pause of using your mobile devices will have quite a significant effect on your daily life. What are your analog activities? These is something I need to reflect upon. For a start, rediscover what you like to do when you're young? Long forgotten hobbies? That's a good start!

Yes, I've installing and setting up my printer and scanner drivers the wrong way (using the official M2070W drivers from Samsung) for so long. There always this conflict between the printer and scanner driver everything I've upgraded my Ubuntu distro. It took me a while, but I was made aware there have been this The Samsung Unified Linux Driver Repository since 2015. Adding a repository, update, and install the necessary drivers and everything works as intended.

Timezone cheatsheet in MySQL. Timezone is always tricky and to do it correctly or explain it persuasively to layman.

This Week I Learned 2017 - Week 52

Last week post and something from the current and previous years.

Last week of the year 2017. Is good to have some reflection by looking back at all the blog posts for the whole year. In total, including this post, I've written 75 posts, 17 more posts that last year. My plan for next year is hopefully even more post but on diverse topics rather than usual technical stuff.

Sedentary lifestyle is still an issue although how much I tried to get more active in my daily life either at my office and my home. The heatmap below illustrates that. Compare to last year, I'm comparatively less active. As you age, metabolism drop and lacking physical activity does impact you health someway or another. One good indicator is you gain more weight. Furthermore, you have to spend more money to buy new cloth. Having a pedometer does help but it's good you can have a weekly review of your daily steps taken. Having a weekly review on the step taken or exercises done is the plan for the next year. Adjustment through adding one or two micro habits into your daily life here. Awareness is the key here.

FOSS contribution? Unfortunately, still nothing much even though the daily commit streak was there. Is an ongoing battle on what to work on and pushing the first commit ahead. Although I've tried to created a few new project but didn't pursuit much ahead. My weekly reflection indicated that trying to do too many stuff at one time will make you overwhelmed and nothing much get done. The usual Analysis Paralysis symptom. Adjustment for 2018? Keep the daily streak but be more focus and set priority on what you want to do. Finish what you plan to do. If you can't, delegate or postponed it to a scheduled date, and move on to something else.

And this is how I plan to do in coming year of 2018.

Enough rambling, back to the usual stuff.

What did I miss? That probably the most important question you should either ask yourself or the domain expert in the pursuit of improving or mastering your craft. I've long seek the answer to this question. How good can you be? What is your threshold of your skill? The book The Talent Code did provide some answers (one of it is practice or the way how to practice but there is more to that). However, the missing piece is still how to sustain the curiousity to move forward, especially you've done the craft long enough and stuck in the "same sh*t different day" or "been there done that" mindset. This is very true when comes to software development where each year, some new techs were "rediscovered" again and again. However, this does not apply to professional sport where your genetic and age will play a crucial role in advancing your craft.

In MySQL, ON DELETE NO ACTION is the same as NO ACTION RESTRICT. Yet another quirk of our beloved MySQL database. Compare to the standard SQL or other real databases,  InnoDB storage engine does not supports deferred check, meaning that you can take no action on deleting a record during a transaction and resolve it before completing the transaction. Yay! Embrace the powerful feature of MySQL!

React is the future, inevitably you have to embrace it and add it to your front end development stack one way or another.

This Week I Learned - 2017 Week 37

The old stuff or last week post?

Slow week but things are moving ahead. More focus and getting more deep work done.

Familiar name that caught my attention while watching the game demo. Glad to see him living his dream and doing what he love. He is part of the team (Ninja Theory) that developed Hellblade: Senua's Sacrifice (watch the development diariesIGN's review, or GamePlayHK's broadcast) is worth checking out. I've wondered, what if I'm more persistent and follow his path?

The Search for Better Search at Reddit. Every initial search implementation starts with default Database's own internal natural language full-text search implementation. For PostgreSQL is Tsearch2 and MySQL is FULLTEXT index.

Different publications have different writing style guides. If you're going to publish to their journals, follow their convention.

When comes to affordable (ahem, cheap) amplifier, Lepai is a well-known brand and the general most people would recommended it as your first amplifier. However, there was confusion about another brand, Lepy or Lvpin, which was initially thought as a clone but actually is the same company but a new name. To differentiate this, Lepai brand is used in US or internationally by Part Express and Lepy brand is used in China or TaoBao. Different name confused and influenced my search effort as I was searching for the wrong brand name. Nevertheless, if you searching for Lepai amplifier in MY, search for "Lepy" keyboard instead.

Even though these are cheap amplifier, the audio amplifier chip (more on this later) and quality of the capacitors will determine the overall sound output and pricing. Some audio enthusiasts with good electronic knowledge will purchase this category of amplifier and upgrade or modify it with better parts.

Tripath TA2020 is interesting audio amplifier chip. IEEE ranked it as one of the microchip that shock the world as it allows consumer grade sound systems to produce higher sound at a lower price. It even created a new amplifier category, Class-T amplifier, which is a proprietary variant of Class-D amplifier.

Entry level amplifier typically based their design on these few variants of Class-D/Class-T amp chips.

(1) Tripath TA2020A/TA2020A+ (20 watt per channel), TA2021, TA2024(15 watt per channel).
(2) Texas Instruments TPA3118 (30 watt per channel).
(3) STMicroelectronics TDA7492PE (45 watt per channel).

Discussion on different audio amplifier brings no benefit if you're not a audiophile or trained ears to notice the subtle differences. For a beginner, start with the cheapest possible amplifier available at your place.

This Week I Learned - 2017 Week 33

Last week post or the old ramblings.

The Vox POP is probably the most entertaining and educational YouTube channel right now. I wish they produce more and frequently.

Mommy, Why is There a Server in the House? Suitable for those who are active in /r/homelab.

Refurbished my battle station and upgraded my Fedora 25 to 26. Nothing special about this release and I was expecting something significant or may be I miss out something?
$ sudo dnf upgrade --refresh
$ sudo dnf install dnf-plugin-system-upgrade
$ sudo dnf system-upgrade download --releasever=26
$ sudo dnf system-upgrade reboot

Gigabyte MA10-ST0 powered by Intel® Atom C3958 SoC. A 16-core Atom (C3958 SoC) server board which can be a good server-based motherboard for virtualization or NAS. Think ESXi, FreeNAS, or Proxmox. I was thinking of buying and setting one up for data hoarding.

Does programmer needs office? Definitely. I still fail to understand why corporation still craze over open office floor plan. It's very hard to concentrate without any distraction. People walking by and talking non-stop. Collaboration doesn't means physical communication, it can be done through any messaging app. Private office does works. The funny thing is, I miss cubicle. At least you can really concentrate and work in the zone.

Unknown electronic parts? Get it from Octopart. Buying chips and checking availability? Find Chips.

Speaker broke down and I need to get a new pair of cheap bookshelf speaker. Initially was searching for a pair for good bookshelf speaker like Pioneer SP-BS22-LR, but unfortunately, this model have been either phased out or you have to purchase whole Hi-Fi set. Meanwhile, no local distributor is importing Micca PB42x. I read good review on Swan HiVi D1010-IV or Swan Hivi D1080-IV, might as well allocates budget to purchase this instead. Luckily we can still find it from the local supplier and the price still acceptable, within MYR 450-plus. All this discussion about cheap and good quality speaker is useless if you can't can't hear audio quality? Otherwise, you're just wasting money without any actual benefits.

When you have a pair of speakers, to get the best out of your 2.1 setup. The next purchases will a Digital Analog Conveter (DAC), which convert binary bits (zero or one) to analogue signal and a amp. If you have a DAC, you can skip buying a sound card. Popular DAC is Behringer UCA202 or UCA222 and for amp, Lepai 2020A+SMSL SA50Diagram below illustrates this setup.

Slow MySQL performance in Docker instance? Use TMPFS, where you put the whole database into the RAM. The approach for MySQL docker instance seems easy enough to setup and there have been many documented results.

Why are we trying hard to optimize the MySQL Docker instance? One of the main issue is that big database restoration may kill the MySQL daemon due to either large volume of records. Which begs the question, how many rows? This is determined by server parameter of `max_allowed_packet` or adjust the server according to these parameters.
- bulk_insert_buffer_size = 256M
- innodb_log_buffer_size = 64M
- innodb_log_file_size = 1G
- max_allowed_packet = 1G

While we're on MySQL, it seems we can delete records from two tables in one DELETE statement. The key thing here is the columns from both tables need to be specified.
DELETE a.*, b.*
FROM table1 a
LEFT JOIN table2 b
ON =

It has been a while that I talked about Perl. Getting unique array list. Sigh, every single damn time I've encountered this I was wondering why this is not built into the core language itself?

GNOME is 20 years. It has been so long since I first tried it. I'm getting old. After Ubuntu switching to GNOME as default desktop environment, I felt that GNOME have finally won the GNU/Linux desktop war against KDE after so many fricking years.

No space life in Docker Machine in Windows? Maybe you can recreate another `default` Docker Machine following these settings. Assumed you're using VirtualBox.
$ docker-machine create
--driver virtualbox
--virtualbox-memory 8096
--virtualbox-disk-size 40000

This Week I Learned - 2017 Week 31

Another week, another post. Looking for last week post or something from the archive?

The annual nature appreciation week. Didn't realize that such a place exists in this country. I really need to brush up my local geographical knowledge. However, nature should be explore in its natural form, as in camping, not from some resort built near to it.  And the food, that's a lot to be desired. Pity though.

Fighting with idiotic MySQL 2013 lost connection error for the past week with the Docker instance. Tried different approaches to tweak the server so the database restoration process won't kept throwing such error. In the end, proceed with Plan B approach by changing the mysqldump script so that it will skip extended insert. The side effect of such approach is that the dump file will be bigger and database reloading will take longer. But something working even though slow is way better that something broken. In coming weeks, will look into different approaches, for example, putting the whole test databases in memory (using tmpfs approach which can speed up testing), mysqlpdump (parallel version of mysqldump), or using ProxySQL.

Scientific communication as sequential art. I hope one day that the academic world will publish literature in more readable and accessible way. Actually it's not that hard, some common sense with certain good "taste".

Unit circle. After living for so long, I finally grok trigonometry and understand what the heck is sine, cosine, and tangent.

If you've fork a repository and want to sync from the remote upstream? Two steps. First, set up the remote upstream URL. Second, sync the fork from the upstream.

This Week I Learned - 2017 Week 28

Last week post or something from the archive.

Another long and outstanding issue resolved. While I'm not partially involved but glad it has finally been settled in a mature and non-violent manner. Long story short, is a long story. Nevertheless, everything back on track and are quite a few things I need to follow up and get it done by this year. Half year have gone and not much time left before the end of 2017.

When you're switching character set and column collation in MySQL, you will encounter certain limitation of the index length of Innodb storage engine, the error of 'The maximum column size is 767 bytes.' . There are three ways to resolve this issue. First, you resize the column size from VARCHAR(255) to VARCHAR(191). Second, you resize the the table index length. Third, you switching the storage engine from Antelope to Barracuda and then switch the table to dynamic row format. Similarly, MySQL utf8 to utf8mb4. This post summarized three essential SQL statements needed to do the migration.

MySQL, while is a pile of mess, is a good case study of Worse is better. Likewise, same goes to Craiglist. Say you want about the site, which still stuck in the early 90 design, but still making profit until this day. Sometimes, good enough should be sufficient.

Everyone's code basically sucks, including yours. Honest insight on what you will learn after many years into software development. Importantly, don't get too comfortable in any job. In the end of day, you're delivering software to solve problem, is all what the stakeholder wants, nothing more and nothing less. While some have more pessimistic view of moving to management instead of development and managing up (some said it's overwhelmingly cynical or Machiavellian).

The hierarchy of 'Troubleshooting Software Problems. Probably the best thing I've read so far on how to troubleshooting any problems. The hierarchy of problem as shown below:
  • data
  • code
  • workflow
  • design
  • architectural
  • team
  • project
  • organizational
  • leadership / existential

Is our eating habit, and thus eating habit influenced by "the array of microscopic organisms that live inside our intestinal tract." The whole thread was an interesting read with comments backed by scientific research. Maybe gastrointestinal microbiota is manipulating our eating behaviour. Which leads to the new type of obesity treatment through gut microbiome transplant. In other words, taking care of your gut is one of the essential way to stay healthy and fit.

Shelving and checkpointing in Subversion. It has been so long that finally someone look into adding local commit support. However, it's just the initial stage although there are many design documents available.

Where We Started. The movie and the guitar song. The former is a low budget movie with witty dialogue and the later made me want to pick up guitar again.

This Week I Learned - 2017 Week 26

Last week post or browse the archive of mindless ramblings.

Week 26 of 2017. We've finally reaching the half part of the year. So many things to do, so little time available.

"Eat food, not too much, mostly plants.". Avoid white processed food or any kind of fast food. Sounds simple right? Hard for us to follow. With a tendency of bridge, especially during dinner and sedentary life style, I doubt anyone have the time to eat a proper good healthy meal. What can we do then? Read discussion on forum and read scientific papers, and develop your own methodology. Good example of such research. However, some studies were paid studies to fit certain agendas, checking for a reputable sources is quite difficult due to signal to noise problem. Furthermore, most discussions are just personal anecdotal, which you know, is just a sample size 1 observation or N = 1 situation. To reduce all these noises and personal anecdotal, do your own research and refer to few reputable sites like NHS Choice and Harvard Health Online (paid subscription). Everyone mileage may varies, as we tends to trust our body and conduct N = 1 experiments on ourself.

Be careful when going to any chiropractors, don't let anyone have a quick jerk of your head. Better still, see an orthopedist with chiropractic knowledge.

MySQL, seriously, what an effed up database system. Conversion from one character set and collation to another was rather tricky. Resolving "ERROR 1071" was not as straightforward at it seems.

Interesting idea. Just focus on 3 things. 3 things per day, per week, per month, and per year. Experience have taught me figuring out which three things is the hardest part. We're constantly fighting over on the should and want.

This is what happened when an organizational system have been practiced rigorously. Way overboard for my taste. But different people have different working style and culture. While it's good to go for simplicity with an analogue approach, but managing index cards the manually way is just way too cumbersome. Pen and paper is good when you don't need to archive the information and can simply throw it away.

Meanwhile, the post on electric typewriter and reading environment gave me an idea on converting my Raspberry Pi into one digital typewriter. I just need to setup my writing environment with a monitor, mechanical keyboard, a mouse, and a good reading lamp. Just fire up the tiny box and start writing. Jot down what ever come to you without any prejudices and judgement. And eff grammar.

Why process is important? Cognitive errors more likely to happen than procedure errors. Stick to the process.

Fanny pack and Underbone (kapchai). These are like almost like everyday carry (EDC) and yet I don't even know the actual names.

Seeking job fulfillment? Depends on what you want or to sugar coat it, whether its align with you moral and ideological compass. Some don't dream big and content with their role, even through with minor contributions. Some based on ideology. If you want better pay, you will likely to end up with job you don't like, just like 98% people out there. Or maybe you should take a different view, the job itself is just your bread and butter, use the money to do something you find more fulfilling. Provided that you save your income aggressively like 25 times annual expenses.

Something of similar nature, how not to bring emotion from work back to home or how do you decompress after work?

Another day, another weird validation rule when using Vim and LaTeX.

GNU GPLv3 turns 10. What a long way to go since the first decade. Like it or hate it, this license have significantly changed the whole computing industry, especially free and open source software development. Without it, we are still at the mercy of proprietary licenses in all our computing devices. If you ever use any free and open source software and benefits from it, it's time for you to help out, sign up and be a member!

"TDD failed for economic reasons, not engineering ones." This is so true for legacy system when you want to add new feature but don't want to break existing stuff.

This Week I Learned - 2017 Week 25

Last week post or you can explore the archive.

Writing and nothing but writing. Imagine starting from 8 in the morning until 12 in the night, minus the eating time and occasionally short breaks, you have to write up something to fill the remaining 12 pages. Staring at the monitor for 16 hours non-stop will definitely depleted you and causing much stress, especially to your eyes. The sudden and urgent feedback caught me by surprise. Totally messed up my daily routines. The aftermath of this last minute changes is you have become wordy, like one of those week I've experienced before. Therefore, this week blog post will be a bit wordy than usual.

One hard lesson I've learned during this writing period, reading and lots of reading is essential for writing. There is no way for you to churn out anything fast, if you don't even have a clue on what you're going to say. Want to be a better writer? Be a better reader. Reading a technical paper and a fiction requires different strategy. The former needs a systematic and structural way of extracting information. The later, you just need to use your imagination and indulge with it.

Another one. Statistics is very important, far more practical and relevant than other branches of mathematics. You never know when you going to need it, but when you do, you really do! Time for relearn and pick up some statistics.

The next lesson? I think I finally and partially understand what the heck is methodology, which in short, a set of practices or procedures. To explain in another way, a step-by-step procedure on how you going to tackle a particular problem. Particularly, you have to explain when, where, and how you're going to carry the procedures. It changed how I read, understanding, and absorb information. In the end, all the details, some ways or another, are transformed into a flow chart.

Back to the regular weekly ramblings.

Via Reddit. World oldest gymnast, Johanna Quaas, 91 years old to be exact. Nothing but good genetics, healthy and active lifestyle, be independent, and how to age gracefully. There are so many ways your body will let you down and kill you when you age. Genetics aside, which is out of our control, this is definitely doable, you just need to have the persistent and patience to do it. Seems that cycling is preferable than running, if you don't want to damage your knees due to running.

Do you plan your next day ahead? I've been facing the same problem in organizing my life. It's a long tedious process of trying different organizational systems (Four Quadrants / Eisenhower BoxGTD, Bullet Journal, and Pomodoro) to see which one sticks. Typically, nothing stick for a long time, after a while, you will drifted away and back to your old self. The main issue procrastination. You're aware of the priority, but don't feels like doing it. Then it dawned to me that time management is actually mood or mind management. If you need to to something important, schedule it at the time where mentally you're most alert and aware. For example, early in the morning when you first woke up is probably the golden hour of productivity.

Maybe the mentioned systems are way complicated as it can lead us to overly micro planning. Remember, there is no one true system, it's a mixed of everything with some adaptation. Why not going analogue and low tech with a simple pen and paper. Jot down your to-do list, prioritize, try to get things done within that day will work. Not every day is a perfect day. Accept it. Not everything will be completed within that day. Reschedule the unfinished tasks to the next day. For more refinement, break the day into four sessions of morning, afternoon, evening, and night.

Regardless how you optimize your day, the first thing is to plan ahead, way ahead like life goals from 6 months to 30 years. The longer the planning, the more you will aware that most things don't matter that much in life eventually. I agreed with the poster's four assumptions, especially that "productivity is getting the most important things done" and "most people don't have that many things they truly want to accomplish.".

Classic Papers: Articles That Have Stood The Test of Time. Collection of ten most cited papers from different area of research. Unfortunately, only from 2006. It would be nice the paper can be extended from far longer before 2006, say from 1900. Interesting found was this paper, Who should fix this bug? where the author was using machine learning to semi-auto assign a reported bug ticket to the a developer.

LaTeX, where what is hard is easy, and what is easy is hard. Editing LaTeX file with Vim? Plenty of errors that you probably needs to amend to make it go away. Generating PDF file and the page dimensions seems off? Readjust the page margin dynamically. Sigh. No matter how much I love typesetting, the hassle and effort of tweaking the layout is not worth the time.

When using Git, branching is easy and cheap. Two things that I need to use quite often when merging changes from different branches. First is create more throwaway branches and squash merge using the `--squash` parameter. Second is cherry picking using the -n parameter. Both ways do merge but not commit the changes.

This Week I Learned - 2017 Week 22

Last week's post or the whole series.

Slow week. Lots of pending stuff needs to be cleared off.

One of the best thing in learning, always be the most stupid person in a class and ask a lot of questions. You never know you will learn something new or relearn something old. Or it may reaffirm some beliefs you always held truly to yourself.

#1 If you need to display CJK characters and emojis in MySQL, use 'utf8mb4_unicode_520_ci'. Historically (another good write-up), MySQL support 'utf8mb3', later changed to 'utfmb4', and changed again to 'utf8mb4_unicode_520_ci' (since MySQL 5.7), and lastly 'utf8mb4_0900_ai_ci' (since MySQL 8.0). Sometimes you wonder why you still stuck with the curse of MySQL where there are better solution out there.

`utf8mb4` is the superset of `utf8`. Meaning that the former also includes the later character set.

To show the supported character set in your MySQL installation.

First check your MySQL version.
mysql> SHOW VARIABLES LIKE "%version%";
| Variable_name           | Value                   |
| innodb_version          | 5.7.18                  |
| protocol_version        | 10                      |
| slave_type_conversions  |                         |
| tls_version             | TLSv1,TLSv1.1           |
| version                 | 5.7.18-0ubuntu0.17.04.1 |
| version_comment         | (Ubuntu)                |
| version_compile_machine | x86_64                  |
| version_compile_os      | Linux                   |
8 rows in set (0.33 sec)

Next list our the available character sets for `utf8mb4`.
mysql> SHOW COLLATION WHERE Charset = 'utf8mb4';
| Collation              | Charset | Id  | Default | Compiled | Sortlen |
| utf8mb4_general_ci     | utf8mb4 |  45 | Yes     | Yes      |       1 |
| utf8mb4_bin            | utf8mb4 |  46 |         | Yes      |       1 |
| utf8mb4_unicode_ci     | utf8mb4 | 224 |         | Yes      |       8 |
| utf8mb4_icelandic_ci   | utf8mb4 | 225 |         | Yes      |       8 |
| utf8mb4_latvian_ci     | utf8mb4 | 226 |         | Yes      |       8 |
| utf8mb4_romanian_ci    | utf8mb4 | 227 |         | Yes      |       8 |
| utf8mb4_slovenian_ci   | utf8mb4 | 228 |         | Yes      |       8 |
| utf8mb4_polish_ci      | utf8mb4 | 229 |         | Yes      |       8 |
| utf8mb4_estonian_ci    | utf8mb4 | 230 |         | Yes      |       8 |
| utf8mb4_spanish_ci     | utf8mb4 | 231 |         | Yes      |       8 |
| utf8mb4_swedish_ci     | utf8mb4 | 232 |         | Yes      |       8 |
| utf8mb4_turkish_ci     | utf8mb4 | 233 |         | Yes      |       8 |
| utf8mb4_czech_ci       | utf8mb4 | 234 |         | Yes      |       8 |
| utf8mb4_danish_ci      | utf8mb4 | 235 |         | Yes      |       8 |
| utf8mb4_lithuanian_ci  | utf8mb4 | 236 |         | Yes      |       8 |
| utf8mb4_slovak_ci      | utf8mb4 | 237 |         | Yes      |       8 |
| utf8mb4_spanish2_ci    | utf8mb4 | 238 |         | Yes      |       8 |
| utf8mb4_roman_ci       | utf8mb4 | 239 |         | Yes      |       8 |
| utf8mb4_persian_ci     | utf8mb4 | 240 |         | Yes      |       8 |
| utf8mb4_esperanto_ci   | utf8mb4 | 241 |         | Yes      |       8 |
| utf8mb4_hungarian_ci   | utf8mb4 | 242 |         | Yes      |       8 |
| utf8mb4_sinhala_ci     | utf8mb4 | 243 |         | Yes      |       8 |
| utf8mb4_german2_ci     | utf8mb4 | 244 |         | Yes      |       8 |
| utf8mb4_croatian_ci    | utf8mb4 | 245 |         | Yes      |       8 |
| utf8mb4_unicode_520_ci | utf8mb4 | 246 |         | Yes      |       8 |
| utf8mb4_vietnamese_ci  | utf8mb4 | 247 |         | Yes      |       8 |
26 rows in set (0.00 sec)

However conversion from `utf8` to `utf8mb4` will encounter these issue of `ERROR 1709 (HY000): Index column size too large. The maximum column size is 767 bytes`. There is a DAMN good guide (ironically better than official documentation) written to resolve that issue and planning for the migration. However, the SQL queries only works for MySQL 5.6.

Meanwhile, this is one good example of writing Perl unit test cases to evaluate `utf8mb4` character set.

#2 Found the solution to my long unanswered question. When writing Bash script, how do we skip certain parameter. For example, we want to skip first parameter but takes the second $2 parameter onward? `shift` my friend. Is a universal concept that I've looked at it almost every day in Perl but never occur to me that this is the same in Bash script as well.

#3 PostgreSQL 10 with examples. The only worthy stuff produced by HP besides the printer. People, embrace the most advanced FOSS database system. Stop playing with MySQL.

#4 Time your console commands but cannot capture the output of `time` to a file? You're not using the command correctly. You should surround it with parenthesis. Either one will work. Depends on how many output files you want to have.
$ (time ls) > outfile 2>&1
$ (time ls) > ls_results 2> time_results

#5 How do you lost 1kg per week or the perfect diet? Both gave the same good advice. It actually make sense without actually starving yourself. The key take here is to first figure out the daily needed calories. Then reduce 500 calories from your food intake and add activities that burn 500 calories as well. The second part make sense. You just don't focus on diet, you should incorporate physical activities as well.

#6 "How do I get started with artificial intelligence?" and "What can I do with AI in my own product or company?" Read this.

#7 The technology stack of craiglist. Surprising, they are using Sphinx Search Server. Thought they might be using Elasticsearch. Why? Based on the comparison on both search servers, Elasticsearch scores way higher than Shpinx. Maybe Sphinx fits the requirement usages in craiglist?

This Week I Learned - 2017 Week 20

Last week stuff or the previous posts.

The battlestation have been acting up this week again. Repeated restarts is getting old and rather annoying. Maybe it's a good time to sell it and build a new one instead, probably based on Ryzen. However, the next question to ask is do you want it or need it?

It was so simple that I was shaking my head wondering why it was never occurred to me before. Eating dinner at consistent times of the day will have significant impact on you, both physiological and psychological. Having your dinner before 7 p.m. seemed to have noticeable effects on my body weight and quality of sleep. This is one habit that I need to follow through.

#1 The Starfish Story. Everyone can make a difference in the world, no matter how small the change is. You just have to work fscking hard and stop being lazy. Or maybe taking the opposite approach instead? By adapting a minimalist lifestyle?

#2 While we have web proxy server, it seems that database system also have their own proxy server. For MySQL there are two popular DB proxy servers, ProxySQL and MaxScale. Sadly, I've never implement either one of them in actual production environment. Not everyone works with web scale system.

#3 nftables, iptables replacement. Installation procedure as follow.
$ sudo apt-get install nftables
$ nft --version
nftables v0.6 (Support Edward Snowden)

#4 Google I/O 2017. However, one of less obvious announcement that caught my attention is that the programming language Kotlin have been officially supported on Android. Steve Yegge's long post (HN and Reddit discussion) on the language, as usual, was an interesting read. Maybe it's a good time to start looking into long postponed Android development.

#5 How to start Web Development in 2017. The same old things repeated again and again but getting more and more complicated. Numerous technologies have been superseded by the core essential always remains the same.

#6 Michael W Lucas, interesting author who published both nonfiction and fictions books.

This Week I Learned - 2017 Week 19

Last week post or the whole series.

Slow week but nevertheless, it was an interesting turn of event. Can't wait for more excitements to unfold in coming week. Importantly, never lose focus on your goals over petty things.

#1 One of the best experience shared I've read when comes to employment agreement. Always read the agreement carefully and lawyer up when necessary. Emphasis added by me.
I got sucked into a dispute with a former employer once over intellectual property rights in an employment agreement. They kept trying to sneak in a clause into the agreement in every other paragraph that gave them ownership of, full rights/responsibilities for, and access to, anything I did remotely related to programming or computers outside of work while not on the clock. It was so broad, even my non-lawyer ass knew it was an awful thing. It became a deadlock argument back and forth until I asked if they were accepting liability for any illegal activities I could perform outside of work. Suffice to say those clauses disappeared by CoB the next day in the agreement.
#2 Perl's answers to the Fizz-Buzz question.
#! /usr/bin/env perl
use strict;
use warnings;
use 5.024;

my $t = <>;
chomp $t;

for my $ins ( 0..$t-1) {
    my $limit = <>;
    my $sum = 0;
    map {
        $sum += $_ if ($_ % 5 == 0 or $_ % 3 == 0) 
        } 0..$limit-1;
    print "$sum\n";

What interested me is not the solution but the input from the diamond operator (<>) used within this context, which itself is also another interesting story. The diamond operator is useful when writing GNU/Linux console utilities as the operator will work either on standard input or files.

#3 Probably the best sequence diagram to illustrate an HTTP request through CGI. Source from Web Development with Perl.

#4 Why does Google prepend while(1); to their JSON responses? (via HN)

#5 Why you should just use PostgreSQL if you're using Open-sourced database systems? See the number of features (those in green) available. Sigh. Yet we still stuck with MySQL.

This Week I Learned - 2017 Week 18

Last week post or you want to read through the whole series.

Since the prevalent of Internet these days, we're more connected that ever. And yet, we're even more isolated. More and more shopping malls and residential areas are being built especially around the transit stations. Basically all looks the same and people are discourage to travel to another town anymore because everything is available either online or at your nearest malls.

Sick. Down with fever. It has been a while since last time. No one but myself to blame. For people around my age, good rest and food is a way to healthy life. We're not seeking prolonged life but prolonged health.

#1 So, what's your Plan B? Good discussion from the comments. While there is some sort of discrimination against older programmers, but the reality is older programmers may just burn out or bore doing the same mind-numbling stuff over and over again. Yes, the same sh*t but different day. Not everyone have the opportunity to work meaningful projects (yes, subjective view), but most of us just work on some glorified spreadsheet or database skin. You see the same mistakes repeated over and over again from different systems and it's just pointless or bother to raise it up again.

#2 On becoming a low-level programmer. There is a curated list of information especially on the hardware part.. There is also another list of learning the fundamental of computer science. So many things to learn and explore and yet, so little time. Sometimes the reality of life commitments limit our choice on the thing we want to pursuit. I need to finish everything by July before I can start to clear the list from my bucket list. One step at a time. Follow the system.

#3 First, make it work, then make it right, and finally, make it fast. Get the thing to work first before you're thinking about making it right (giving the right name) and optimize it. Fulfill the requirements of the stakeholders first (prototyping) before you're looking into doing it right and fast. Something I need to remind myself constantly as we're often obsess with perfection. What's the point if your build it the right way and fast but does not meet the stakeholder needs?

#4 How to write a REST client in Perl. Most Perl modules have limited documentation, for example, little example on how to use the APIs. This is where PHP (it has been so long since I mentioned something about PHP) really shines. As the language is slowing dying, there are little or no good example on how to start something up fast.

Meanwhile, something rather interesting about Perl. I've seen quite a few Perl codes with subroutines that prepended with ampersand (&) operator. Basically, the ampersand is needed if you're calling a subroutine before its declaration. Off course, there are many other reasons and usages to use the ampersand, but commonly as reference to a subroutine.

sub hello {
    print "hello";

When using OO with Perl, you will need to instantiate the constructor or method invocation through the arrow (->) operator (a reference). Good examples given below.

Using the arrow notation or virtual method.
my $apple = Fruit->new("apple");

Using the double colons notation or static method.
my $apple = Fruit::new("apple");
Fruit::get_price($apple, "usd");

However, to invoke the method either statically or virtually, you'll need to write the constructor as follow.
sub new {
    my $self  = shift;
    my $class = ref($self) || $self;
    return bless {}, $class;

#5 "error: src refspec master does not match any." Silly me. You need to commit something locally before pushing to remote Git server.

#6 Tiny Python Notebook. Definitely not tiny but quite comprehensive guide to Python 3.6.

#7 How to unstage all staged files in Git? It's so easy that the best answer is not upvoted enough.
$ git reset

#8 Postgres Weekly. When come to FOSS database choices for web application for Intranet application, I'm strong opinion that PostgreSQL should be the default choice. Feature like Range Types and others solves quite a lot of issues and save lots of developer-hours. Yes, MySQL has its own usage, but for any business application which involves monetary and strong ACID compliance, it's not a right choice.

This Week I Learned - 2017 Week 10

Last week post or just follow the whole series.

Got my result today. It seems I've officially "crossed" the borderlines stage. I'm still contemplating on the next step but drastic life style changes is inevitable (more in item #5). If left untreated, it can grow into bigger problems, not only for yourself, but for your loved one as well.

#1 You May Want to Marry My Husband (via HN). Beautifully written. We need to be constantly reminded of the fragility of life especially contemplating one's mortality. The lack of awareness will bite you and your loved ones somehow in the future. Over 30-something and still bogged down by random trivialities in life? Nothing but continual reflection on your life priorities (often misplaced) and gratefulness helps to make peace with current and past self. Regrets? Yeah, plenty. Who doesn't? But not to a point where you will lament later in life that you should, would, or could. Wish you've taken a different path? Nah. I'm good. Yes, there is still room for improvement. Looking forward to that.

Further reading. The 10 Best Modern Love Columns Ever.

#2 On Perl. Interesting thing learned. How do you clone a hash and at the same time, reassign new values to some of the existing keys? Simple and yet so effective. To explain this,  `%$foo` expands expands the hash into a key-value pair and the curly braces (anonymous hash constructor) will create a new hash reference. Output is from Devel::REPL module, the modern Perl interactive shell.
$ my $foo = {a => 1, b => 2, c => 3};
\ {
    a   1,
    b   2,
    c   3
$ my $bar = {%$foo, a => 4, b => 5}
\ {
    a   4,
    b   5,
    c   3

Instead of just doing this.
$ my $foo = {a => 1, b => 2, c => 3};
\ {
    a   1,
    b   2,
    c   3
$ my $bar = {%$foo};               
\ {
    a   1,
    b   2,
    c   3
$ $bar->{a} = 4;
$ $bar->{b} = 5;
$ $bar
\ {
    a   4,
    b   5,
    c   3

#3 Carton. Bundler for Perl. In other words, module dependency manager for Perl. Is Perl a lost cause that only a few diehard users still using and maintaining it? Seems likely to me.

#4 Ship daily. That probably the way to get your side project moving and don't feels like you're not completing anything. Can't do it? Maybe you're setting the bar too high and setting yourself up to failure. Of course, some are created to be thrown away. While I don't totally agree on the needs to to finish all your side projects, but when comes to actual paid work, we need rethink our role. Instead of a programmer, think yourself as a problem solver instead. A tiny shift of that mentality will get you closer to the deliverable.

#5 Getting older? Getting weaker? Maybe you should check your weight and measure your Body mass index (BMI)? If so, you should to readjust your diet. Stop eating like you're in college days. More (not just) portions of fruits and vegetables? Furthermore, be informed and mindful of what you put inside your body. Of course, exercise is needed as well. However, exercise alone does not lose weight. Joao Venture have experienced weight lost by reducing most of his sugar intake and maintaining 3 km daily walks per day. Using this calculator, 3 km is 3937 steps, rounded to 4000 steps. Those who works as software developer with sedentary life style, it's a struggle to reach 4000 on daily basis.

Looking through my steps count below, both my mean and median are roughly around 3000 to 4000 range. This fulfill at least one of the criteria. The next step is to adjust my diet by reducing my sugar intake. Interestingly, since the beginning of 2017, I only manage to hit 10000 steps only four times!

On a related note, sleep is also a crucial factor as well. What Kind of Sleeper Are You?

#6 The Unofficial MySQL 8.0 Optimizer Guide. The section on profiling is interesting and I really don't have time to go through each item on databases I'm working one. Definitely going to improve any legacy and messy databases.

#7 When comes to programming, some of us still missing the point that we're a problem solver first and a programmer second. Follow a process and the convention. Prioritize. Keep the solution simple (yes it maybe boring) and don't try to do things the fancy way unless really, really necessary.

This Week I Learned - 2017 Week 07

Last week post or the whole series.

When come to getting new stuff, I really should have a one-item policy. For example, if I'm going to get a new bag, either I sell off the existing bag or donate it out. Otherwise, no point having two bags where you only going to use one. Not only is wasteful, it's also a hassle to store it and clean it as well. Something for me ponder upon when I'm thinking of getting any new stuff.

#1 Six modern keys to wealth. HN user, monodeldiablo describes six possible ways for anyone to accumulate wealth. In essence, you should be competent (both book smart and street smart), persistent (perseverance), and extraordinary lucky (right place, right time, and right people).

Developers are generally book smart but always having difficulties to monetize their projects or technical ability (turn it into a business). The most recent example is JWE, the author and maintainer for GNU Octave is looking for job after 25 years of maintaining the software (I think he is doing a great job since he have been doing it for 25 years but having some financial difficulties these few years). I've made a small contribution to him and being a FSF associate member can help too (just make a note in your monthly contribution). Expect some blog posts on GNU Octave in coming future.

#2 Coroutines in Perl? Use Coro module. More on asynchronous programming in Perl in coming posts. Busy week and I can't seem to allocate any time to look into this. So many things to follow up and so little time.

#3 Prioritize! Prioritize! This reminds me of Stephen Covey's four quadrants approach (similar to The Eisenhower Method) of prioritizing to-do list and time management.

#4 theXeffect subreddit. Fundamental approach to build habits and prevent procrastination. Also known as the "Seinfeld Strategy". Following Bombjoke advice, the steps as follow.
  • Buy a pack of index card. Get the one from Daiso with 5mm grid.
  • Start with Boléro by Maurice Ravel as your background music.
  • Pick a daily habit you want to develop. May I recommend meditation?
  • Write the reasons on why you want to develop the habit on the back of the card.
  • Start now. Do the habit. Once done, mark a big 'X' on the box. If you fail, mark a big 'O'.
  • Continue for 66 days or 2 months. A habit is formed after that period.
The index card by hardcase00 shown below is a good example to illustrate the steps mentioned. Look closely at the card. In order to continue the streak, he have different minimum meditation time ranging from 5 seconds till 15 minutes. Set your goal so low and easy that you don't have any excuses of not doing it. Remember the main purpose is not to focus on how long you can meditate but to develop a habit of daily meditation.

#5 Software developers who started after 35. I have mixed feeling about this. Is good that anyone who are diligent enough can pick up software development skill but Peter Norvig's post on teaching yourself programming in ten years reminded me otherwise. Well, it depends on how you see software development itself. Is it a tool for your to achieve your goal? Or a skill you wish to gain and master? Different people have different motivations.

#6 Is PostgreSQL good enough? (via HN) By far, best written technical post I've read this year. Sad about the font size though. Seriously, who read at such small font size? I've seen quite a few systems which can benefit greatly if they switch to PostgreSQL instead of MySQL. MySQL, being popular and easy to learn doesn't means that it's suitable for all scenarios.There are other requirements where PostgreSQL fits, for example, PostGIS. For a comparison between two to programming languages, MySQL is like dynamic-typed programming language and PostgreSQL is like static-typed programming language. If I'm going to develop any intranet web application which involves critical financial information, my first choice is definitely PostgreSQL.

#7 Goals are for Losers. Passion is Overrated. Provocative opinion but make sense. You need to implement a system or habit to achieve what you want in life. Not passions or goals. Example from the slide is losing 10kg is a goal but eating the right way is a system. To increase the success of what you want in life, use a system approach to acquire more skills which can increase your odd. Summary of this approach. Item #4 is also another good example of systematic approach increasing the success rate of what you want to achieve in life.