OzMoroz Blog

Databases Matter

2011-11-24T19:41:00.001+11:00

Databases are at the core of virtually all modern information technology systems. Sometimes these databases are exposed, for example, as in data warehouse systems. The centrepiece of a system like that is a powerful industrial database such as Oracle, or Sybase, or Microsoft SQL Server, or something similar. The presence of a database is pretty obvious in that case – only these powerful databases can crunch the immense amounts of data processed by data warehouses. In other cases databases are hidden. For example, Apple iTunes uses a SQLite database to store the details of music tracks on your computer. That database is not obvious; it does not advertise itself, but it's there. It makes sure that the ratings you assigned to songs are saved and can be synchronised between all your iPhones and iPads. It counts the number of times every song was played so that you don't listen to the same song twice when you put your iPhone on shuffle. Databases are everywhere. They all serve the same purpose – to store data and make its retrieval as easy and fast as possible – but they are also vastly different from each other.

Let's take another example. When you log into your Google account and bring up your Gmail inbox, all the emails you see are actually stored in the remote database. That database is called BigTable, and it contains not only your emails, but all the emails of all Gmail users in the world, and also virtually all of Google's data. While your iTunes SQLite database may be about 50 megabytes in size (and that's assuming you have A LOT of songs), Google's BigTable contains petabytes of data. That's your iTunes database times one billion.

If you think about it, it becomes obvious that these databases require vastly different approaches to the way the data are stored and retrieved: You can fit an iTunes database into memory and query it whichever way you like without a performance penalty. At the same time, no machine has been built yet that could apply the same approach to Google's BigTable.

Unfortunately, not all software developers understand that. Databases once were an inspiring topic but in recent years they went out of fashion. Software developers are geeks; they like new toys; they all want to work on something latest and greatest and cutting-edge. So many new exciting things are happening in the area of Information Technology – Web 2.0, HTML5 and Apple iOS to name just a few – that databases just fade in comparison, despite the fact that they make all these new shiny things tick. Most of the developers these days take a database just as generic data storage: “We'll just stuff the data in and we don't care what's inside.” 10 years ago SQL language was a necessary skill for database application developers. Nowadays the majority of programmers don't know SQL. They rely on frameworks such as Hibernate to produce SQL statements for them. They think that all databases are the same and therefore, if necessary, they can take one system that uses MS SQL Server as a backend and put it onto Oracle and it will work just fine.

Well, that may be true for very simple applications. The myth that all databases are the same is flawed, especially when it comes down to performance. Today cloud computing is a buzzword, and Google is the patriarch of the cloud. Google's servers process billions of requests every day, crunching petabytes of data. Yet, every request made to a Google search engine is served within seconds. This places such a high demand on the Google's database layer, that Google's engineers couldn't afford using even the most powerful of industrial databases, and they had to develop their own – the aforementioned BigTable. If you told these guys that “all databases are the same”, they would laugh into your face, and rightfully so, because Google knows that performance matters and they try to squeeze every bit of performance out of their systems.

Databases matter, and if you consider yourself a decent software developer, you need to learn how to tame them. Learn the differences between them. Learn what they are, what makes them tick, and the most importantly, how to make them tick faster, because writing applications that are slow is just bad taste.

Nokia+MSFT: Power of Incentives

2011-02-15T16:42:00.007+11:00

Considering that the present Nokia's CEO Stephen Elop is one of the largest individual shareholders of Microsoft, no wonder they tied a knot.

Source: dailyfinance.com

And it'snot a surprise he tries to talk the Nokia's share price down. He doesn't currently have any Nokia shares, but he will have to buy some soon. And the cheaper Nokia shares are, the less he will pays for them.

As Charlie Munger puts it:

‘I think I’ve been in the top 5% of my age cohort all my life in understanding the power of incentives, and all my life I’ve underestimated it. And never a year passes but I get some surprise that pushes my limit a little farther.’

Make your life happen

2011-02-14T13:04:00.001+11:00

Jason Fitzpatrick quit Lifehacker. Here's what he has to say:

The only commodity we have is time. Somewhere—in your mind, on a notepad, stashed in a virtual notebook—you have a list of things you'd like to be doing with your time before it all slips away. Do what you have to do to take those ideas out of storage and make them happen. You can trade and barter for a lot in life but you can never buy back time. Go live.

These Are the Last Words I Have to Say; That’s Why This Took So Long to Write by Jason Fitzpatrick

Freediving in the Philippines. Epilogue

2011-02-09T18:30:00.004+11:00

Some people asked me why I needed that. Here's why.

I do not know where to start... Perhaps I should start by telling how a long time ago, when I was a kid, I watched a movie called "The Big Blue", and it forever imprinted in my memory, somewhere between the French cartoon "Time Masters" and the Bratislavan TV series "She Came Out of the Blue Sky".

Table of contents:

Afterwards I always wondered how Luc Besson at such a young age (when the movie came out in 1988, he was 29) could make such a powerful movie. That is, up until I looked at the page about him on IMDB, from which I learned that young Luc loved the sea. He planned to become a marine biologist specialising in dolphins. But at the age of 17 he had an accident which rendered him unable to dive.

I grew up in a place called Sochi on the coast of the Black Sea. Swimming and diving were always a part of my life. And I did it neither better nor worse than other boys. I do not know exactly when it came upon me, but somewhere by the end of high school I started to realise that the sea gives me a whole new world – I just need to submerge my head under water. Then the fuss and noise of the world goes away and a new freedom appears – freedom to swim like a dolphin. And in this new world I feel at home. Unfortunately, back than I didn't know what I could do with my newly discovered talent.

It was only 10 years later when I discovered the Internet, I found out that I was not the only one, that there were others sharing my passion, and their name was "freedivers". And the very first website where I came across the word "freediver" was Julia Petrik's site "Homo Delphinius ".

Further, as I found the clue, I began unwinding it. I read all I could find about freediving in Russian and, when I moved to Australia, I started exploring the English-speaking Internet. So, Homo Delphinius was followed by Deeperblue.com, then by Umberto Pelizzari's book The Manual of Freediving. This book gave me all the theoretical knowledge I needed. But I still could find no opportunity to apply it in practice.

In Australia, freediving as a sport is poorly developed. There are spearfishers, but somehow I wasn't interested in killing fish. It is ironic that in a country, which is famous for its achievements in the field of water sports, there wasn't even a branch of AIDA, the International Association for the Development of Freediving, three years ago. Now we have one, but, unfortunately, it is sort of virtual. Although Australia has its own freediving team and records, there is neither formal training nor AIDA-accredited courses. Nevertheless scuba diving is very popular, and dive shops offering PADI (Professional Association of Diving Instructors) courses are practically in every suburb. I obtained an Open Water Diver certificate just to realise that scuba diving was not what I needed. When I was putting on pounds of equipment, including a massive tank and BCD, I was losing that freedom to swim underwater like a dolphin, which attracted me to the underwater world in the first place. Then, because of the lack of a better option, I started playing underwater hockey. This was a dynamic game and good exercise, but that crazy romping in the pool was not what I was looking for. Unfortunately, underwater hockey did not give me the second component of freediving – the silent tranquillity.

Well, that is almost it. From time to time I thought about going somewhere to learn freediving. To Moscow, perhaps, or to Egypt. Or to England for Deeper Blue's course in the SETT pool. But it was all so far away and so expensive....

And then one day I saw a post at one of the online forums. The post was saying that the group of Russian freedivers led by Julia Petrik was about to have a freediving course on the Philippine island of Cebu and invited whoever was interested to join. I saw it – but didn’t pay much attention. Thought I was too busy at work, at home (I have a small kid and it was still a long time till annual leave). But a few days later I returned to it. Something clicked inside me, and I decided to go, no matter what. I took an unpaid leave, got my wife's approval, contacted Julia, and bought a plane ticket. And yet even then I could not believe that I would get there. All that was too good to be true.... Then a few days before the scheduled departure I had a pretty serious food poisoning and lay in bed a couple of days with a fever. I thought I definitely wasn't going anywhere. And yet destiny wanted me to go.

You know about the rest. All that has accumulated in me over the years or even decades of searching unwound in a flash, like a compressed spring.
And what comes next – even I don't know.

By the way, Luc Besson now can dive.

The End.

The text © 2010 Sergey Stadnik

Freediving in the Philippines. Day 12

2011-02-09T08:34:00.003+11:00

Here I was writing this diary

Everything comes to an end. It was time for me to say goodbye to the Philippines, that hospitable place, which gave me so many new impressions over the last few days. At eight in the morning, a taxi was to pick me up and take me to the airport. Three hours in the car, then an airport, a plane, and three and a half hours to Singapore. Mark, Michael and I met for breakfast. Last conversation, goodbye. Then I went to say goodbye to the sea. I looked at the bright blue surface stretching to the horizon, and tears rolled down my cheeks. Then I jumped into the car and set off for the airport. On the way, I asked the driver to drop in at Club Serena, but having arrived there, I found out that everyone else had already left.

Airport, customs, passport control... All of those necessary attributes of travel are the same every time. They take a lot of time, but there's no way to go around them. And when yet another door closes behind you, you realise that something is over, finished. And something new begins.

Table of contents:

Singapore. How strange it was to plunge into this world after the quietness and calmness of the Philippines. Bustling airport with trains running between terminals, roads with five lanes in each direction, hurrying people... Civilisation. And in the Philippines I did not even have a TV in my room, although I can't say I missed it.

Singapore, Clarke Quay

I had five hours before the flight to Melbourne, while my Russian friends had seven hours before theirs to Moscow. We jumped into a taxi and went to Clarke Quay, a place Mark recommended. The Moscowers were astonished by the cleanliness around them. As for me, that place reminded me very much of Melbourne. And the fact that we drove on the left side of the road only added to the similarities.

Clarke Quay resembled Melbourne's South Bank a lot: a place on the river bank, where both sides are packed with restaurants. A lot of delicious food and hordes of tourists. Since we couldn't fit into a single car, we arrived in two taxis. I was in the second, and we left the airport a little later. When we arrived, the guys from the first batch had already dispersed. I was disappointed – I hadn’t said a proper goodbye to everyone yet. I set off on a task of finding them, and I spent the next hour running from one restaurant to another on both sides of the river. I knew their phone numbers, but my phone for some reason worked very poorly and I could not get through to anyone. Finally, I found them all in one place – at "Quayside Seafood" restaurant. I still had time and I could not pass up the opportunity to have a dinner.

We drank beer and ate fish and crabs. And when it was about time for me to go, I picked up a glass and said a very simple toast:

— Thank you for changing life.

I do not know whether they took me seriously, but I was absolutely serious. Something happened to me during those two weeks. Yes, I did things that I didn't know I was capable of. But still that is not the point – meters and minutes are not of critical importance. The experience itself was the most important. Probably, an astronaut who goes for a spacewalk experiences something similar: emotional shake-up so strong that it permanently changes the outlook on life. I know that happened to me. I do not know what I am going to do with it, but I have no doubt everything will be as it should be.

Night Singapore

When I try to trace the chain of events that led me to the Philippines, I wonder how it all fit together. This chain is stretched for years, and perhaps for decades. Decisions taken, at first glance completely unrelated to each other, formed in a line along which I walked. At job interviews I was often asked where I saw myself in five years. I never knew what to answer, but now I know even less. Can we plan our lives ahead?

For example, Mark, as I said, changed his career as an IT manager in Singapore for the role of hotel manager in the Philippines. How could it have been planned five years earlier? Some might say that I believe in destiny, and maybe I do, but not quite. In fact, life is not a straight line. The world is not static; it is constantly in motion, in a perpetual state of chaos – which actually might not be chaos. We just do not know the rules of the game, so when something unexpected happens, we call it an accident. Events collide and intertwine, forming a network of possible choices and consequences. At certain points in life, everyone comes to a place from which he can turn right or left. And depending on that his life will turn out differently. We can not plan our futures five years ahead. We can only hope to be in the right place at the right time and pull the right string.

But that’s not all. I believe that sometimes the probabilities add up themselves, stars align, and what should happen happens. That happens not always and maybe not for everyone, but sometimes that is enough to forever change someone's life.

I said goodbye to everyone and departed. I still had half an hour, and I walked along the river in the Singapore night. Then, with some difficulty, I caught a taxi and went to the airport. Airport, passport control, customs... Seven hours of a night flight. And in Melbourne's airport I was met by my family.

My vacation was over, but what I experienced will stay with me forever. And I hope that wasn't the last time.

The End.
Although, not yet. Some people asked me why I needed all this. Okay, I'll tell.

The text © 2010 Sergey Stadnik
The photos © 2010 Sergey Stadnik, Vasily Avseenko
The music track used in the video is "Nine Voices" by "Yes".

Freediving in the Philippines. Day 11

2011-02-08T18:18:00.004+11:00

A restaurant at "Blue Orchid"

Back when I was preparing for the trip, I got in touch with Julia, and she told me that I had a choice to stay in one of two hotels: Club Serena or Blue Orchid. I looked at the Blue Orchid's website and, to my surprise, in a left-side menu found a link labelled "Aikido". Since I am a black belt in aikido, I was interested. The link itself did not lead anywhere, but after a little research, I discovered that the owner of Blue Orchid, the Englishman Michael McCavish, was a fifth dan of Tomiki aikido. I contacted him, explained who I was, and asked if I could book a room at his hotel. Michael replied that he was glad that I would stay at his hotel, but he at that time would be in Japan on business.

When we first saw him in the evening after returning from Badian Resort, the first thing he said to me was: "I came back a day earlier than planned. I felt that I had to talk to you." I did not even know what to think about it. Another coincidence in the chain of random events? Maybe. Maybe not.

Table of contents:

I did not dive on this day. Firstly, my ear was aching more and I did not want to submerge my head underwater. And secondly, I felt that I had already achieved everything I came for. But one thing remained – I had to talk to Michael. A fifth dan means decades of hard work and discipline. There aren't that many people in the world who achieve that.

Our last dinner table at "Club Serena"

Michael showed me his aikido style. I myself do Iwama style, which dates back to Saito Sensei, one of the senior students of Ueshiba, who was the founder of aikido. Iwama is considered to be a style that conveys what Ueshiba himself did most accurately. Although, honestly, no one knows exactly what he did. Kenji Tomiki was also a student of Ueshiba, but apart from that he had eighth dan in judo. And the style he created combines the techniques of aikido and the competitive spirit of judo. In Iwama aikido there are neither competitions nor fighting. It is believed that competitive spirit contradicts self-knowledge and self-improvement, which are the essences of aikido. In Tomiki aikido, contests are part of the program. Both these points of view have the right to live.

Michael spent a couple of hours with me and showed me his style. Frankly, I was somewhat confused. The techniques he demonstrated were on the one hand familiar, but on the other hand executed in a completely different way. Moreover, they were named differently too. I do not know if I learnt anything from that exercise, but it was very interesting.

Launching a flying lantern

And then we sat at the lunch table and talked about the role of chance in our lives and of the choices we make. I had three recent examples in front of me: my own, Michael's, and the hotel manager Mark’s. Just two months earlier Mark worked as a manager at Hewlett-Packard in Singapore. Then Michael offered him a job as a manager of the hotel; Mark moved to the Philippines and since then has been living there. How's that for a career change?

That was our last evening in the Philippines, and Club Serena's owners decided to arrange a farewell beach party for us. After the sunset a dinner table was set for us on the beach, just like on our first evening. And there was dinner, and wine and rum flowed like a river. There was a surprise too. A flying Chinese lantern was prepared for each of us. Such a lantern looks like an inverted paper bag with a candle attached at the bottom. The candle burns and fills the space inside with a hot air, which makes the lantern fly. Everyone wrote a wish on a piece of paper and put it into his lantern. Thus, everyone's desires were to rise into the sky. However, we were unlucky: there was a breeze and many of the lanterns fell into the sea. But if you ask me, that was symbolical that freedivers' desires fall into the sea rather than take to the air. I think that's the way it should be.

The end of the eleventh day.

The text and the photos © 2010 Sergey Stadnik

Freediving in the Philippines. Day 10

2011-02-08T08:07:00.004+11:00

A view fon the roof of "Blue Orchid"

Surprisingly, I did not have a hangover next morning. Either I did not drink as much as I thought I did, or the quality of the local rum was much better than I expected. Therefore I, as usual, appeared by the pool of Club Serena at 10 a.m.

We had a depth diving scheduled for the morning. A buoy was put right beyond the reef for us, and those few people who were able after the previous day's celebration swam to it, accompanied by Julia. To be honest, I did not want to dive deeply on that day. Although I still wanted to know what I was capable of and knew that I hadn't reached my limit, somehow I was sure I wouldn't dive deeper than I already did during that stay. And besides, my ear started to ache. Earache is an occupational illness for all depth divers. The combination of cold sea water and high pressure does its work, and a diver is prone to picking up ear infections. The nearest doctor was three hours away, so I decided to wait until I got home to Melbourne.

Table of contents:

We started to dive in turns, but apparently everybody was worn out. I dived to 22 meters. It was a good result for me, and it showed that I could dive to 20+ meters pretty comfortably. Although I did not beat my previous record on that day, I was OK with it. Everything has its place and time, and I knew I would have another opportunity sooner or later.

A turtle

Furthermore, I began to realise what was holding me back. It wasn't the pressure – even at 26 meters I could successfully equalise pressure in my ears and I felt no chest compression. That is, I could go deeper. But I was getting out of breath. Also, I just didn't have the proper equipment. My Mares Volo Race fins were good for swimming, and they proved to be excellent for underwater hockey. But still they were very soft and not made for freediving. They simply did not give the necessary propulsion. The first stage during a deep dive, when you have to overcome your own buoyancy together with the resistance of water, is very important. And you will need all the power your fins can develop. The monofin, of course, is the most effective in this case. Especially the so-called "hyperfin" – almost all of our experienced guys had them. "Hypers" have a different foot pocket design. In them, the heel is raised above the surface of the blade to compensate for the relative weakness of the ankle muscles. This is uncomfortable but effective. "Hypers" are sold in many countries, but manufactured mainly in Russia. They have already revolutionised the fin swimming sport and now almost completely conquered the world of freediving. Fins made of carbon fibre or glass fibre are also very efficient, whereas my fins, made of rubber and plastic, were not as good.

A scene with a guitar

Besides, I was plainly freezing. As I mentioned earlier, my own open cell wetsuit was too warm for the tropical waters of the Philippines, while the borrowed 3mm steamer, as it turned out, was too cold. The problem was not even that the wetsuit itself was thin, but that the cold seawater could freely pour under the collar, cancelling out all the thermal insulation provided by the rubber. There are suits with tricky zippers, in which this problem is solved. Next time, if I won't be able to find an appropriate open cell suit, I will at least get one like that. As I said before, in between dives freedivers lie still on the surface of water with little or no movement. Those were the moments when I was freezing. I had to twitch my arms and legs to warm up, and as a result I could not relax.

That morning I was not the only one who was freezing; and after diving for an hour, we returned to the shore. After dinner we settled upon going to another reef, where Julia wanted to film for her TV project. Since I was getting cold in the water, I decided to try to dive in my own open cell wetsuit.
The reef turned out to be very close to the place where we were diving to the plane. Once we arrived, the preparations for the filming started. The theme was musical. The guys fetched out a violin and a guitar. The guitar was bought here on the island a few days earlier. I saw it before, but couldn't guess what kind of fate awaited it. The guitar was a key part of the script. However, getting it underwater turned out to be not easy. The guitar was too buoyant and it took a 2-pound weight to sink it. I pulled on my wetsuit and plunged into the water. And then I was up for a big surprise.

Badian Island Resort, reception

When I had dived in the borrowed steamer, I attached a 2 kg weight to the belt to offset its buoyancy, and that was enough. I knew that my open cell wetsuit was more buoyant, and put 3 kg of weight on the belt. Turned out, that was not enough! I could dive with great difficulty – the suit kept me on the surface. So I had to go back to the boat and fasten one more weight. That helped a little, but still was not enough. Unfortunately, I didn't have any more weights. Furthermore, the suit was clearly too thick for tropical waters, and I was getting hot. Meanwhile, a few meters below the surface the underwater concert was in a full swing. The show was really beautiful; and maybe we will see the video one day. However, I soon realised that my clumsy figure could accidentally get on camera so I preferred to wander off. Since I couldn't really dive because of my buoyancy, and I was getting hot, I soon returned to the boat, pulled the suit off, and just relaxed and waited for the rest of the guys to return. It was not my day.

We had yet another trip planned for the evening. We booked a dinner at a prestigious hotel, Badian Island Resort. Julia stayed at that resort with friends on the previous New Year's Eve and loved it. That resort is on a separate tiny island, and usually only the resort's guests are allowed there. But we boldly introduced ourselves as a team of tour operators from Moscow, and they made an exception for us. For a modest fee of 1500 pesos (around $30) we were promised a tour, a buffet dinner, and an entertainment program.

Spas with rose petals

It was already dark when we set off. From our hotel we had to ride 40 minutes by car to the pier, and then travel for another 10 minutes on a boat to that island. Once we disembarked from the boat, we were welcomed by girls from the Badian Resort's staff. They presented each of us a necklace made of flowers and asked us to walk over to the reception. There we were asked to pay upfront. Then the tour followed. The problem with the tour was that it was already completely dark, and we couldn't see anything. Nevertheless, we were shown around the island. Despite the pitch black, it was obvious that Badian was an exclusive resort for the rich, where the number of staff exceeded the number of guests. Massage rooms and spas with baths covered with rose petals were all around. At one place a cascade of personal swimming pools was arranged so that occupants could lie on special couches (yes, right in the pool) while watching the sunset. After some time, since we could not see anything anyway, we were shown directly to the area around the main pool, where the dinner tables were set up. I have to admit that the dinner was delicious.However, we soon found out that drinks were not included into the price we paid. In front of me at the table stood a bottle of red Australian wine – Hardy's. I asked how much it was. Having received the answer, I converted it into Australian dollars, and it turned out that the price was about three times more than I would pay in Australia. I decided to pass with Hardy's and ordered a glass of a house red instead. In the meantime, we were all looking forward to the show.

For those 10 days while we were in the Philippines, we didn't see any manifestation of the local culture. And we were very interested to hear and see some local songs and dances, something ethnically Filipino. On the other side of the pool, where a small stage was installed, two men with guitars appeared sometime later and started singing. They sang in an unfamiliar language, perhaps one of the Filipino languages. When they finished, lights turned on over the lawn next to the stage. Music started playing, and a group of dancers in ethnic costumes ran out onto that impromptu dance stage. I can not say that they danced badly, on the contrary – it looked very nice. It just didn't feel like Filipino dancing. Rather, it was entertainment for foreigners, folk dancing to Western music.

The folk dance show

They danced a few numbers and even tried to lure us into a dance and, to some extent, succeeded. After them a man with a guitar came to our table and started singing. He sang a very sad and very long song in an unfamiliar language. It is unclear why he decided that this song was perfectly suited to this moment. For the first few minutes we endured that. Then someone offered to give him money to go away. After a few more minutes we couldn't take it anymore, and one after another started fleeing from the table. Finally he finished his song and left. After that an elderly Caucasian man walked to our table.He turned out to be the hotel's owner himself. He greeted us on behalf of the resort and presented a free drink for everyone, which slightly warmed our Russian souls. And then the entertainment continued, presented by the already familiar Filipino "Simon and Garfunkel" and dance revue. The man with a guitar didn’t come back, thank God.

When the entertainment program was over, we decided that we ate and drank enough, and made for our hotel. But we had a discussion and decided that, as "tour operators", we would not recommend that place to our clients. Maybe it's good for wealthy retirees, but personally we liked the hotels we stayed in much better.

When we returned to Club Serena and I, having opened the bus's door, set my foot on the ground, I saw a tall Caucasian man waiting for us.

“Is one of you Sergey?” he asked. “I am Michael, the owner of ’Blue Orchid’".

The end of the tenth day

The text © 2010 Sergey Stadnik
The photos © 2010 Sergey Stadnik, Vasily Avseenko

Freediving in the Philippines. Day 9

2011-02-04T08:32:00.002+11:00

I began the day with a remarkable feat – I got up early and went to yoga at 6:15 a.m. Yoga is cool, but because I wasn't used to it, for me doing it was tough. By the end of class I could not wait for it all to end. We agreed, as usual, to meet at 10 by the pool, and I went to my hotel for breakfast.

On that day we were going to have practical tests for freedivers' certificates. As contenders for the two-star freediver level, members of our beginner group had to do the following:

Remove the mask at 10 meters and surface without it.
To simulate a leg cramp underwater, remove one fin at 10 meters and resurface using the remaining one.
Perform stand-by protocol for another freediver, accompanying him to the surface from 10 meters depth.
"Rescue" a freediver from 10 meters.

Table of contents:

The more experienced guys who were going for three stars had to do everything the same, but from 15 meters depth. Oksana briefed us and explained the rescuing techniques. In the meantime a couple of buoys had been put in the sea just beyond the reef in front of our hotel. I borrowed a dive computer from a friend who wasn't going to dive with us. And after the briefing, we suited up and swam to the buoys. One buoy was intended for us to do our tests, while at the other one more experienced guys, who didn't have to do the tests, practised depth diving. We began as usual with some exercises. I pulled myself down and up the rope by the hands a few times, then dived once using fins, and after that told Oksana that I was ready.

Underwater forest

The first step was to remove the mask at 10 meters. To make it more clear for us, Oksana tied two tags to the rope: at 10 and 15 meters. I dived to the first one and, holding to the rope with one hand, I pulled off the mask. Removing the mask at this depth felt like hitting my face against the water. And instantly I saw almost nothing. I know that scuba divers can even put on a mask under water, displacing the water from it by exhaling through the nose. But scuba divers have plenty of air, while freedivers do not have that luxury. Therefore, clutching a mask in one hand and clinging to the rope with the other, I swam up. I passed the first test. In fact, everyone did that without any problems, but not everyone liked the experience. Then it was my turn to pass the second test. I dived to 10 meters and, holding to the rope, took one fin off. And, holding the removed fin in one hand and guiding myself along the line with the other hand, I swam up. Pretty soon I realised that paddling with two legs did not make sense – the bare foot provided no thrust. Therefore, I went on ascending working with one fin only. Piece of cake. And then the most interesting part started: performing stand-by duties and rescuing another freediver.

As I already wrote, freedivers do not dive alone. When a freediver dives into depth, he is watched by another freediver from the surface. The safety freediver dives to meet the ascending freediver and accompanies him to the surface. Because most troubles usually occur to a freediver in the upper 10 meters on ascent, that is where he should be met. If a dive isn't very deep, about 30 meters, such a dive usually takes little more than a minute, and it is easy to calculate the time when a safety person needs to dive. Besides, an ascending freediver is visible from the surface. Freedivers who dive to greater depths usually know how long it takes and let the safety diver know when and at what depth they need to be met.

When it was my turn to take the test, Oksana dived, and I was lying on the surface watching her silhouette fading out of sight. When she disappeared completely, I dived after her. I stopped at 10 meters and watched her rising from the depth. When she came up to me, I started ascending alongside her, looking into her eyes. The safety person needs to see the eyes of the freediver, to be sure that she is all right. At any hint of an abnormal behaviour he should be ready to come to the rescue. I passed that test successfully. After that I only needed to rescue a freediver from 10 meters. The exercise started the same way as the previous one: I dived after Oksana and I was waiting for her at 10 meters. When she levelled with me on her way back, her body went limp – she portrayed the loss of consciousness under water. If that happens for real, it is a critical moment. After losing consciousness under water, a person may instinctively try to inhale. Once water enters the upper respiratory tract, one more reflex kicks in, this time protective – the trachea is closed by so-called laryngospasm, and the water doesn't get into the lungs. But in that case time is crucial – there will be about two minutes before laryngospasm is released. If a freediver is not brought to the surface within that time, the water will get into the lungs, and the diver will effectively drown and will have to be given CPR. Once Oksana "fainted", I, as she taught us, grabbed her under the shoulders and dragged her up.

During such a rescue, the first thing to do on the surface is to hold the unconscious diver so that the airways are above the water. Then you need to take off his mask and call him by name. If a person does not regain consciousness, then hold him with your right hand under his head, pinch his nose, and do mouth-to-mouth resuscitation. That is what those of us who were going for two stars had to do. The guys who were going for a higher level additionally had to transport an unconscious diver to the shore and do CPR.

I passed the test on the second attempt: the first time I forgot to pinch Oksana's nose while doing mouth-to-mouth. But the second time made everything right.

When we all passed our two-star tests, the guys going for three stars had to do all the same. However, they had to "rescue" a freediver from 15 meters. When it was Vasily's turn, Oksana said that it would be good for him to save someone else. She was already tired of playing a "victim". Moreover, for Vasily that would be too easy: he is about 100 kg, and Oksana is a frail and slender girl. So I volunteered to be rescued. I dived to the 15-meter mark and then dropped a bit deeper until the computer on my wrist showed 18. I started ascending, and when I caught up with Vasily at 15, I closed my eyes, released the rope, and went limp all over. Before I could relax, I felt that I was being dragged up. Then everything went according to the plan: he pulled me to the surface, removed my mask and did resuscitation. Because I passed all the tests, I didn't have to do anything else, and I asked Oksana's permission to do some depth diving practice at the other buoy.

That time Tania was my safety freediver. The first time I dived to my usual 20 meters. Then, while I was waiting for my next turn, I tried to relax and catch my breath as I was taught. Then I handed over the snorkel to Tania and dived.

When I was going up, it seemed that the rope in front of my eyes was barely moving. And I felt like darting to the surface as fast as I could. However, that would lead to nothing good. I once read an interview at the deeperblue.com website with one of the students of the freediving course in the SETT pool in England. He started to have diaphragm contractions at 25 meters and he bolted for the surface. He was lucky not to black out. And an instructor who was diving next to him was trying to calm him down all the way to the surface. Panicking under water is the last thing you want to do. Bad thoughts need to be banished. You should be calm, thinking about the light and blue sky that is waiting for you on the surface. And paddling by slow but wide fin strokes: one, two ... until you feel like in the last 10 meters positive buoyancy embraces you and brings you to the surface. Immediately after surfacing it is necessary to make a quick exhale, then take a deep breath and breathe deeply for a few seconds. Then the official protocol requires you to remove the mask, to show the "OK" hand sign, and to say, "I'm OK." During all those activities a safety diver and, if that happens in a competition, a judge is staring into the eyes of the freediver. In tournaments, there were cases when freedivers lost consciousness after having already gotten to the surface. If this happens, the result does not count.

Having caught my breath, I looked at the computer on my wrist, which embodied the depth to which I dived – 26.1 meters. And having left the guys at the buoy, I swam to the shore. I accomplished more than could hope for. I was happy.

After lunch, we went diving to the sunken plane. The plane itself is an old small "Cessna", which was thrown to the bottom specifically for tourists to dive to. It lies at 20 meters depth, which slightly varies depending on the tide. That was just about on the verge of the depth to which I could dive comfortably, and I was wondering if I could get to it. But before we could dive to the plane, first we had to find it. The plan was such that the captain of our boat with his local assistants would locate the plane and place the boat right above it. Then we would throw a line straight down, and dive along the line to the plane. When we got aboard, the captain, a Filipino, cast a glance at our uncomplicated equipment, assessed the lack of scuba tanks, and asked:

– Snorkelling?
– Yep, – we confirmed – snorkelling.

However, not all turned out smoothly according to plan. The visibility in the water was less than 10 meters, and the plane couldn't be seen from the surface. The search took a while, but finally it was found, and a rope with a weight was thrown down. And then we faced another surprise – a strong current. The buoy drifted, and a rope was hanging out of plumb at a 70-degree angle. In such circumstances, the only sensible way to reach the plane was to go down the rope, though not straight down. If a freediver tried to release the rope, he would be instantly carried away and wouldn't find the plane. The first guys went down, and upon returning reported that the plane lay at 22 meters. I waited for my turn and, having taken a deep breath, dived down, pulling myself down the rope. Going down against the current was hard; I think it was my most difficult dive there. Perhaps if I was just diving, I would not have reached 22 meters in such conditions. But at that moment when I was ready to turn around and go back, I looked down and saw the plane just a few meters below me.

A few days before, Julia told us that on the Red Sea visibility in the water can be such that the depth tag, which an athlete has to reach, is clearly visible from the surface. She said that being able to see the goal helps immensely and adds strength.

She was right. I reached the plane. I clapped my hand on the roof, looked inside, and then let go of the rope and went up: keeping to the inclined rope upon ascent was not necessary and I wasn't worried that I would surface a few meters away from the buoy. Then I waited for my turn and dived again. This time I even had enough air to swim away from the cockpit and hold on to the plane's fin. On that my diving program for that day had been completed. And I couldn't say I was disappointed by the way the day passed. Oh no, quite the opposite. Later that evening, standing on the beach and looking at the fading sun slowly diving into the sea somewhere far away, I realised that my life was changing forever, right there and then.

And later in the evening we celebrated March 8, which is Women’s Day in Eastern Europe. A table was set for us on the beach. The guys got hold of flowers somewhere in this middle of nowhere, and we presented them to all our girls. And there was a festive dinner. We drank wine and rum, sang songs and danced. I went to sleep after three o'clock in the morning with a firm conviction that no one would turn up for yoga the next morning.

The end of the ninth day.

The text © 2010 Sergey Stadnik
The photos © 2010 Vasily Avseenko, Sergey Stadnik

Freediving in the Philippines. Day 8

2011-02-03T08:27:00.007+11:00

There isn't much to write about that day – we didn't dive. Our team divided into two groups: the majority went to watch cockfights, while the four of us, including myself, returned to the waterfall. Cockfighting is one of the main attractions in the Philippines. It is a horrible, bloody spectacle; and I will let somebody else tell about it. I didn't even want to look at it.

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At the waterfalls Julia wanted to shoot a scene for her TV project. The original plan was to take two rafts: one for Julia and Tanya to go under the waterfall and the other one to film them from. But unfortunately, the place was packed with tourists. The only two rafts were full and many more people were waiting for their turn. So we had to be content with just one raft. While Julia and Tania were dressing up, I and another girl, Oksana, went under the fall to experience its hard shower once more. I took a camera with me and filmed the entire process, thanks to the fact that my little Sanyo could shoot in the water.

Under the waterfall

Then Julia and Tania took the raft, and Oksana filmed them from the shore. After the filming was over, we set off to climb higher into the mountains to reach the second and third waterfalls. They are much smaller, but the third waterfall adjoins a small lake. We took note of its unspoiled natural beauty during our canyoning adventure three days earlier and wanted to come back since then. Julia thought that the lake scene would make an excellent addition to her show. Unfortunately, that place was full of people too. The serene beauty of the Philippine's nature was disturbed; the spell was broken; and filming made no sense. We made a stop at a small restaurant beside the lake to taste local coconuts.

The dam

Coconuts grow right there on the trees. They are offered to tourists on the spot: torn off a tree, then the top is chopped off with a huge knife, and a straw is inserted into the hole. Fresh coconut milk has a different taste than canned. For some reason, canned coconut milk is very sweet and sugary. In fact, too sweet for me. On the contrary, fresh coconut milk is only mildly sweet, and I quite enjoyed it. Once the milk is drunk, the coconut is cut in half. Then with a spoon or just a scraper made of the shell of the same coconut, you can rake out the inner white layer of coconut pulp, which is also very tasty.

It was getting late so we made for the hotel. On our way back we passed a small hydroelectric power plant, which supplied electricity to the village near the waterfall. Just above the falls there is the dam, which entraps part of the river's flow and directs the water to the turbines through pipes. Our guide told us that when the turbines are turned off, the waterfall becomes larger.

When we returned to the hotel, it was already dark. And we were surprised to find that the others hadn’t returned yet. Obviously the cockfights dragged on. But finally all gathered together and we had a dinner. And after dinner, in conclusion of the day, we had another freediving theory lesson.

The end of the eighth day.

The text, the photos and the video © 2010 Sergey Stadnik
The music compositions used in the video are: "Twin Peaks Theme" by DJ Dado, "Straight Lines" by Silverchair, "Too Much Rain" by ATB.

Freediving in the Philippines. Day 7

2011-02-02T19:05:00.004+11:00

On that day Julia planned filming her TV project. On the reef near Pescador Island, where we dived a few days earlier, was an arch in the reef under the water – "The Cathedral". The arch's entry was at 18 meters depth, and the exit at 28. Julia wanted to film herself and few other freedivers swimming through the arch.

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View from the roof of "Blue Orchid

Therefore, in the morning we boarded the boat and went to the island. The plan was to do some depth diving first. We arrived at the island, cast an anchor and dropped the diving line down directly along the wall of the reef. However, we were unlucky. There was a strong current, and instead of going down vertically into the depth, the rope was hanging at a 60-degree angle. Diving like that was pointless. We pulled the weights out and tried to find a better place. Having sailed around the island, we dropped an anchor a few hundred meters away from the reef. There it was a little better, but the ropes were still out of plumb. However, there was nothing we could do, and we started diving. As always, we started with pulling ourselves down the rope by hands. I descended to about 10 meters, and then felt that the rope I was holding to was moving. Caught by surprise, I clung to it and was brought to the surface. It turned out that the guys decided to re-drop the weights and pulled me out with them. Then the current appeared again, and the diving became even funnier than on the previous day. While diving down the line was still OK, on ascent you had a choice of going up holding to the rope, which meant not directly up, or releasing the rope and swimming straight up, surfacing wherever the current took you. A couple of times I was carried to another side of the boat and surfaced a dozen meters away from the place I dived. Also when ascending, I had to continually look up to avoid bumping my head against the boat. The last time I went on the rope down to 21 meters. Tania, who was on a stand-by that day, told me that since I swam up and down at an angle, I could safely assume that I dived to 25. On that the depth diving was over. We weighed the anchor, sailed to the reef and dropped the lines in front of the place where, at a depth of 18 meters, the entrance to "The Cathedral" was located.

Filming underwater scenes on breath-holding is difficult – the cameraman simply does not have enough time at the depth. Therefore, for flexibility Julia decided to send one of our team members down with a scuba. Andrew, himself an experienced freediving instructor, donned scuba, took the camera and positioned himself at a depth of 24 meters inside the arch near the entrance. Julia and Tania were diving into the arch, and Andrew was filming them. In the meantime the others spread out along the reef.

Fishermen near Pescador Island

I floated on the surface above the arch and watched our girls diving down. I was curious what was down there. I took a deep breath and dived. Of course I didn't go into the arch – I'm not crazy – and have a very strong sense of self-preservation. Moreover, I didn't want to dive deeply without somebody watching me. But nevertheless, I very comfortably dove down to a depth where I could see the edge of the hole in the reef and Andrew sitting there with a scuba a few meters below me. I did not have a computer, which shows the depth and time intervals, so I did not know how deep that was, but I reckon about 15 meters. At this depth, my buoyancy was already neutral; I could hang there for some time looking around without moving a muscle. It was very beautiful there. I was hanging in the water column, and right in front of me the reef wall was stretched from surface into the depths. Underwater coral forests played all shades of emerald green in the sun rays penetrating from the surface. Julia and Tania swam past me along the rope and disappeared inside the arch. I hung there for a few more seconds and rose to the surface. I dived a few more times and found that such a depth was quite comfortable to me. It is a pity that I did not have a dive computer. When I depart on such a journey once again, I will certainly buy one.

On that the filming was over and we returned to the hotel. It was about five o'clock in the evening and everyone was hungry, because shooting dragged on, and we were left without a lunch. While we waited for dinner, Vasily suggested that I try to swim in his monofin – we had the same foot size. As I said, monofin is a blade in the form of a mermaid's tail, with attached pockets for both feet. The foot pockets themselves are of unusual shape and the foot inside them is bent in a special way, which is very uncomfortable but provides better performance.

Cameraman

A monofin was invented in the 70s in the Soviet Union by fin-swimming athletes. They became popular in the rest of the world thanks to Jacques Mayol, who received one during his visit to the Soviet Union from the inventor himself, fin-swimmer coach Boris Porotov. These days monofins are not something extraordinary. They are manufactured in a number of countries. But the best ones are still Russian and they are made individually to order. A monofin is much more efficient than traditional fins; however, it has its disadvantages. It does not offer the same manoeuvrability as traditional fins. And it's not the best choice if it needs to be used for a few hours in a row: foot pockets are so uncomfortable that after some time swimming they start to hurt.

Swimming in a monofin was a pretty interesting experience. The small pool did not allow us to develop great speed, but still the power was amazing: three strokes with a "tail", and 10 meters were behind. Even with my practically nonexistent dolphin-style swimming technique. I certainly liked that. I probably would have bought one for myself, but I clearly understood that I didn't need one yet. I didn't know where I could use it. I wouldn't buy it to swim just in a pool, and I would freeze in Port Phillip Bay. With our water temperature, we need to choose the fins in such a way that they could be put on a 3mm neoprene sock.

After dinner, Julia continued to read us freediving theory.

Modern freediving competitions are held in several disciplines: diving to a depth, lengthwise in the pool (dynamic apnoea) with fins and without fins, and the static breath-hold. Currently, man has learned to hold his breath for more than 11 minutes and swim with fins underwater for 250 meters in a pool. But the most interesting competitions are on diving into the depths. They are divided into several types:
Free Immersion – where an athlete dives without fins and pulls himself up and down the line with his hands.
Constant Weight with or without fins – an athlete swims down and up without touching the rope.
Variable Weight – an athlete dives down with extra weight, and at a depth releases it and uses his fins to ascend.
No Limits. Here an athlete holds on to a special weighted platform – a sled – as it carries him along to the depths. At the moment the deepest dive in this category is 214 meters. Coming up to the surface from such depths just by using a muscular force is unthinkable, and that's why special aids are used. At the deepest point a freediver unleashes a gas-filled float, which then pulls him up. Such an extreme is not for everyone, and not just because of the enormous depth.

Club Serena's pool

In this kind of competition an athlete's life depends on technical aids, which can fail. In the history of the competitions, there were several deaths and near-death cases occurred because of equipment: a jammed sled, or a valve of a gas tank not opening. And yet, there are still people who beat those records.

Constant weight with fins is considered the most classical discipline and a highlight of any competition. Here an athlete dives into the depth, counting only on himself. He is one-on-one with the abyss. According to current competition rules, an athlete must declare the depth at which he is going to dive in advance. At that depth a plate with the corresponding number is fixed. The athlete has to grab the plate and show it to the judges upon surfacing. In addition, a depth gauge on the wrist registers the depth. But just reaching the depth isn't sufficient. It is necessary to pass the surface protocol, which states that a freediver must be in full consciousness and behave adequately. If an athlete breaches any of these requirements, he is disqualified.

It's not entirely clear to me why people take part in such competitions and beat records. Any "big" sport brings pain and traumas. As for me right now, I dive into depth, but not for depth. Yes, I am curious to know what I am capable of, but I would never dive to a depth that is uncomfortable to me. While diving, we submerge into ourselves, and that is the only thing that matters.

The end of the seventh day.

The text and the photos © 2010 Sergey Stadnik, Vasily Avseenko

Freediving in the Philippines. Day 6

2011-02-01T19:06:00.006+11:00

Having arrived, as usual, at 10 a.m. after breakfast at Club Serena, I found that almost everyone was so exhausted after the previous day's march, that even the morning yoga hadn't happened. A bit later the people slowly began to crawl together to the pool area, complaining of pain in various limbs.

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Breakfast at "Blue Orchid"

Our spearfishers, once again, went hunting early in the morning. And for the rest of us, at least for those who were able to, a static breath-holding session was planned. As always, it all started with breathing. We gathered at a gazebo on the beach and under Julia's supervision did some breathing exercises for about half an hour. Then Julia told us to disperse, to sit somewhere in a more comfortable position and do a few breathing cycles on ourselves, then to make a single breath-hold on land. After that we suited up and got into the pool.

Just like the last time, we placed ourselves in the water near the side of the pool and started breathing up. Then Julia gave a command to make the last six deep breaths and begin when ready. Having lowered my face into the water, I mentally walked through the entire body to make sure that absolutely all the muscles were relaxed: from the toes up to the waist, up the spine, neck, up facial muscles and jaw, and arms to the tips of my fingers. Then tried to calm down my thoughts and just float still on the surface...

Many say that they do not like to do static. On the contrary, I enjoy it. The relaxation, which comes with it, is unlike anything else. I am suspended in the water completely relaxed. My body weighs nothing. Beneath me and above me – infinity. My thoughts are far away. I do not need to care about anything, don't even need to breathe. My heart beat slows down.

Static

When a sense of discomfort increased, I, as Julia taught, stretched out my whole body and pulled my diaphragm muscle up as much as I could to use the last air stuck in the bottom of the lungs. That gave me another 10 or 20 seconds. Then I raised my head from the water and took a breath. The first time I did 2:50. We started preparing for the second attempt by breathing up. As a rule of thumb, the time at the surface should be 2.5 to 3 times longer than the time spent under water. So after a three-minute breath-hold we breathe for at least 6 minutes. I did a 3:06 on the second attempt and 3:30 on the third. And that was the end of the static session for the day.

Judging by the fins, this is me

And after dinner we took a boat and went to a place where we were told sea turtles could be seen. But on the way we made a stop to have another depth diving training. We dropped two lines – one on each side of the boat. "Advanced" divers occupied one line – and we, the dummies, the other one. During the training freedivers dive one at a time. While one dives, the rest are waiting at the surface and breathing. And the one who is underwater is always watched by an instructor. The practice of freediving shows that all the troubles usually happen to freedivers on the ascent in the upper 10 meters of water. Therefore, a stand-by person dives to meet a rising freediver and ascends beside him, looking into his eyes. This is to ensure that he is conscious. At the first suspicion that something is wrong, a stand-by comes to help and pulls a freediver to the surface.

Unfortunately, we had a chance to make only a few dives. I dove a couple times, pulling myself down the rope. And then suddenly a strong current appeared. I dived, finning down, and upon ascent I drifted away from the rope. I looked up to see where I was going and saw the boat directly above me. I started paddling away to avoid bumping my head against the boat and suddenly found a rope. I continued my ascent along it and upon surfacing found that it wasn't my rope, but rather the rope on the opposite side of the boat. Because of the current it was pointless to carry on diving; and we set off for the reef to look for turtles.

A underwater "flower"

Usually the water in this area of the Philippines is very clean and visibility in the water is at least 15 meters. But on that day we were unlucky: Some kind of haze was suspended in the water; and we could see for no farther than five meters. We dispersed throughout the reef to look for turtles, having promised to shout if anyone saw them. And I soon spotted one. The turtle was about two feet in length. It slowly floated at a depth of several meters; and it was accompanied by a pair of small, needle-looking fish. I called the guys, dived, and swam after it. The turtle noticed me, gained speed, and started escaping into the depth. Who would have thought that that seemingly clumsy creature, slowly paddling with its flippers, could develop such a speed? Soon I needed to surface and had to say goodbye to the turtle. Then the guys came by, but the turtle had already been gone. And because of poor visibility we failed to find it again. We swam for a little longer, then returned to the boat, pulled the anchor, and headed back to the hotel.

Sometime later our spearfishers came back. When their boat came to shore, our entire team gathered there to greet them. The meeting was stormy. It looked as if the tribe was greeting their men returning from the hunt, and, in fact, that was so. It turned out that the hunters shot enough fish for us all. For dinner we had fried fish, fish soup, and sashimi. And another day ended.

The end of the sixth day.

The text and video © 2010 Sergey Stadnik
The photos © 2010 Sergey Stadnik, Vasily Avseenko
The music mix used in the video is "Dreamscapes: Dark Tranquility", radio ETN.fm.

Freediving in the Philippines. Day 5

2011-02-01T08:18:00.003+11:00

The story of this day will not be as long as the previous ones. We didn't dive on Day 5. Instead, we went canyoning.

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At the beginning of the path

Kawasan Falls are located about 20 minutes away by car from our hotels. It is a cascade of one large and two smaller waterfalls. We were told they looked quite spectacular. But just going sightseeing wasn't our intent. Instead, we drove about half an hour higher into the mountains. From there, we were going to walk to the falls. Canyoning means descending down a river. Not on rafts, but on feet. That is, it is literally walking down the bed of a mountain river. Our team was led, once again, by local instructor Wolfgang, for whom organising such routes is a part of his business. He told us that the route was very simple, and even children who could not swim would walk through it. Wolfgang announced that in some places we'd have to jump from small ledges into the water and swim. It did not scare anybody. All present were freedivers, and therefore people of steel, capable of diving down tens of meters on a single breath. However, after just 10 minutes we came to the cliff, which ended with a five-meter drop with a rocky pool at the bottom. Wolfgang declared that we had to jump.

The first obstacle

Most of us were brave enough, and after a few moments of hesitation, we one by one stepped over the ledge and plunged into the river below. However, a few girls were not inclined to jump. Those who already did it tried to cheer up the doubters and convince them that there wasn't really anything scary. It took some, but finally they took a leap of faith, and we moved on. Fortunately for us, that was the largest challenge we faced. For the next three or four hours we hiked down the river. For most of the way the path led us along its banks, but in some places the path was blocked, and we had to march right upon the river bed. Besides, it was a hot day, and stomping upon the water was more fun. Several times we stopped to rest and wait for stragglers. For most of the way the river was about knee-deep or less. But in a few places along our way it formed pools which were quite deep. In such places we had to jump into the water and swim, as Wolfgang promised us, for there was no other way around.

Finally we reached the first waterfall just to discover that is was quite small, just a few meters high. I even thought in disappointment: "Is that all?" But it turned out that it was just the beginning. Ten minutes later we approached the second waterfall, which was a little bigger. And after yet another 10 minutes hiking down the path we saw the third one. And it was indeed a sight worth seeing. Water was thundering down from 20-meter height and like a white shower falling into the lake at the bottom.

We had to swim at some places

However, the magnificent view was just a part of the attraction. At the edge of the lake a couple of rafts were parked. The rafts were made from thick stalks of bamboo bound together with ropes. Our team, accompanied by two local guides, boarded one of the rafts.

One of the guides instructed us to sit down, and then started to pull our raft to the waterfall by means of a clever system of ropes stretched over the lake. But instead of heading for the waterfall directly, the guides directed the rafts into a narrow cave a few meters away. They ordered us to lie down. Everyone obeyed, and soon we understood why that was necessary: as the rafts were moving farther into the cave, the ceiling began to decline and stayed as low as half a meter above the water. There was barely enough room for us to lie down.

The waterfall

The guide continued to pull our raft forward, and in another few meters we made a sharp turn. The cave suddenly ended and we saw a white wall of water in front of us – we emerged beyond the waterfall. The guide gave us permission to get up, everybody jumped to his feet, and soon we entered the waterfall.

The stream of water falling on my shoulders from 20-meter height was an unforgettable sensation. That was like a very hard shower, which burned and cooled at the same time. The raft stopped so that the water curtain divided it exactly in half. We were jumping back and forth through the stream, shouting in wild voices and laughing. Then our guide pulled the raft out from under the waterfall and asked whether we wanted more. All shouted that they did, and the raft once again was directed to the entrance to the cave, and we went through the waterfall over again. And when it was over, we rested at the local restaurant located next to the waterfall, had a delicious lunch, and drank rum. Everyone was tired but happy.

Upon returning to Club Serena, I headed directly to my hotel, because all of us were very tired and I knew that that was all for that day.

The end of the fifth day.

The text and the photos © 2010 Sergey Stadnik, Vasily Avseenko

Freediving in the Philippines. Day 4, part 2

2011-01-28T19:06:00.003+11:00

After the "static" we all went fin-swimming. The proper swimming technique is very important for a freediver because it allows him to push himself through the water column most optimally. I decided to try to swim in long freediving fins and borrowed a pair from a guy who had the same foot size as I have.

This is what I saw waking up every morning

He was learning to swim in a monofin at that time and didn't need them. The fins were too large for me and felt loose on my feet, so I attached them to my feet with rubber bands. That helped and I was not afraid to lose the fins, but the friction of the loose rubber foot pockets on my feet was still pretty uncomfortable. Of our group of beginners, nobody could swim properly in fins because nobody had ever been taught. So, instructor Oksana set off on a task of teaching us.

Table of contents:

The easiest way of fin-swimming looks like this: legs must be stretched out in a straight line, and the fins must be one line with the legs. Then slow and very wide leg strokes are done, without bending the knees. The legs work like scissors. This method is used in vertical dives and underwater swimming. For swimming on the surface the technique is similar, but the sweeps are made in only one direction – from the water surface under the water and back to the horizontal line. Fins should not breach the surface of the water – slamming fins on the surface does nothing. At the same time the hands should be stretched in front of the head to reduce the resistance of the water or, alternatively, to move like in front crawl swimming style. The freediving fins had larger surfaces than my own and swimming in them was harder, but they allowed me to develop a greater speed. I didn't notice any other fundamental difference.

The beach of "Club Serena" hotel

After about half an hour of swimming back and forth, Oksana showed us how to swim dolphin style. Dolphin is a more optimal fin-swimming style – it allows propelling oneself through the water using less force. Therefore, it is used in freediving more widely than traditional style. Moreover, it is the only possible way to swim in a monofin. In dolphin style, a swimmer's legs do not move relative to each other. Instead, the body performs a "wave" that starts from the chest and rolls to the tips of the feet. Of course, it goes without saying that perfecting a technique takes time, but no matter how hard we tried, the result was still uninspiring. After another half hour of our clumsy attempts, we went back to the hotel – to swim in the hotel's pool without fins.

I’ve been swimming for as long as I can remember, but nobody has ever taught me a correct swimming technique. All that I know I learned from watching others do and applying it to myself. Needless to say, I swim – to put it mildly – not entirely correctly. I swim crawl ok. I found that my breaststroke is satisfactory, too, but for some reason I was spreading my fingers during the stroke and the water was literally slipping between them. But I had absolutely no idea how to swim dolphin style. I just did not understand what I needed to do with my hands and legs to move forward. Having looked at my suffering, Oksana told me to try to swim a "two-stroke" dolphin: this is when the legs move as in dolphin and the hands as in crawl. But again – nothing good came out of it. There was absolutely no coordination of movements between my hands and legs; the legs were doing something on their own, and the hands were also by themselves. However, after half an hour of swimming back and forth, something started to come together. By that time everybody was very tired, and a lunch was declared. After the lunch we were going to do deep-diving without fins.

I am relaxing after the hard day

That time a wetsuit was not necessary. So instead of it I put on my stinger suit – a full-body Lycra suit. It does not warm, but it protects from the sun and jellyfish stings. Getting into water just in swimming trunks with unprotected skin is not a very good idea in the Philippines at that time of the year – the water is full of plankton and jellyfish that sting. Most stings resemble mosquito bites, but one of our guys was stung by something pretty badly: highly visible burns on his legs took a few days to heal.

Divers use weights to compensate for the wetsuit's buoyancy. For example, I attached 2 kg of weight to my belt when diving in a 3mm suit, which I borrowed at the hotel. That time the weights were not needed, since we dived without the wetsuits. Led by Julia, our team swam to the buoy, which was already set for us beyond the reef. The technique of depth diving without fins is effectively a breaststroke with minor modifications. It begins with a stroke with the hands, and it is much longer than in normal breaststroke: the arms are stretched down almost to the knees rather than stopping at the chest level. The human body has a positive buoyancy, and shoving ourselves down through the water column without the aid of fins is very difficult, hence powerful and long hand strokes are necessary. After the stroke, arms are returned back and stretched above the head. A leg stroke follows, then the whole body is stretched into a straight line and for a few moments glides through the water. Then the arms do their strokes again, and so on.

The caught fish

We started trying, and I resumed my fight with the rope. A freediver needs to "dive in", i.e., to begin the dive, so that the rope is directly in front his eyes. Otherwise, since we do not look down, seeing where we swim is nearly impossible. In my case, I had a rope appearing anywhere but in front of me. In addition, my arm strokes weren't powerful enough and couldn't push me through the water. Equalising pressure in the ears was also a problem.When we dive in fins, one hand is stretched over the head, and the other one immediately goes to the nose. Therefore, we can equalise at any time. When diving without fins, however, both hands do strokes, and that makes pinching the nose and equalising harder. All in all, I did not do very well and did not dive deep, which is understandably due to my lack of technique. Our diving session didn't last long, because a few people were just in swimming trunks and bathing suits. Jellyfish and plankton made that an unpleasant experience for them, and they asked for a permission to go ashore. Upon returning to the hotel, I grabbed a can of beer, got into the pool, and enjoyed a well-deserved relaxation after a hard day.

A bit later our spearfishers came back and brought two big fish, which were immediately roasted and served for a dinner and turned out to be delicious. The dinner was followed by drinks. Somehow, Moscow freedivers prefer rum to all other drinks. A couple of hours later I went back to my hotel, as it was already too late and a high tide was approaching. Contrary to my concern, I was so tired after the hard day that I fell asleep immediately.

The end of the fourth day.

The text and the photos © 2010 Sergey Stadnik

Freediving in the Philippines. Day 4, part 1

2011-01-28T07:55:00.008+11:00

The day was long, so I broke it into 2 parts.

My room at "Blue Orchid" was in this cottage

In the morning two experienced guys went spearfishing with local instructor Wolfgang. And for the rest of us a training on "static", i.e., static breath-hold was scheduled. It is clear that the breath-hold abilities are of first-rate importance for freedivers: the longer you can hold your breath, the longer you can stay under water and the greater depth you can reach. Besides, the "static" in itself is one of the competitive disciplines in freediving.

Previous chapters:

That morning it all started with Julia's lecture on how to properly hold your breath. Here, again, psychology is no less important than physiology. Nobody knows exactly how the human body works physiologically. But for a freediver it is important to understand that any muscle tension consumes oxygen. And we know even less about how our brain works. However, it is known that the brain is one of the most active consumers of oxygen in the body, especially when we are thinking hard. Therefore, during the "static" it is necessary to achieve two things: complete relaxation of all muscles of the body and the absence of thoughts. But due to the way the brain works, it's unlikely that someone can stop thinking at will. Therefore, freedivers learn to purify their minds and seek the state of detachment, and yoga and meditation help in that.

After the lecture we did some breathing exercises. I've already talked about The Complete Breath. Furthermore, there is a muscle in the human body called the diaphragm. It is located under the lungs and controls the expansion and contraction of the lower section of the lungs. Because the average person breathes mostly with the chest, that is, the upper parts of the lungs, this muscle is not usually well developed. With the help of special breathing exercises originating from yoga, divers develop this muscle which allows them to breathe more efficiently and store more air in the lungs. After the breathing exercises we suited up and went to the pool. Static breath-hold is done in the pool rather than on land, because only immersing the body in the water switches on the diver's reflexes. Each "static" session usually consists of three or four approaches with some recovery time between them. As a result, despite the fact that the water in the pool is quite warm – about 30 degrees – an athlete stays stationary for a long time in the water; hence he might freeze without a wetsuit.

Breathing up before the static

Julia separated us into groups according to our experience – our beginner team had come together again. We took our positions at the edge of the pool and started to relax and breathe deeply. After a few minutes Julia instructed us to take the last six deep breaths, then put on the masks, and, once we were ready, take the last breath and lower our faces into the water. Holding our breath, we were completely relaxed in the water, face down, eyes closed, and lightly holding the edge of the pool with our hands. I relaxed all the muscles of my body as much as I could, yet still needed to distract my brain. Even though my eyes were closed, the sunlight was reaching through my eyelids to my retinas. The light patterns formed into images, and at one moment I clearly saw an image of a sandy bottom through the water column. I imagined I was suspended at 10 meters depth, holding the rope and looking at the bottom 15 meters below me. And that helped my mind to drift away.

The physiology of breath-holding is quite interesting. The air is a mixture of about a dozen gases of which three are the most important to us: nitrogen (N2) 78%, oxygen (O2) 20%, and carbon dioxide (CO2) 0.03%. When we breathe, these gases are dissolved in the blood. In fact, saturating the blood with these gases is what the function of the lungs is. Nitrogen is not involved in the process of respiration; it is excreted from the body in the same amount as it enters. As for oxygen and carbon dioxide, magical transformation happens to them. We all know from school that a person inhales oxygen and exhales carbon dioxide. That is a highly simplified view, but true. The role of the lungs is to saturate the blood with oxygen, which then is spread throughout the body in red blood cells (erythrocytes). This stored oxygen in the blood is the most important source of energy for all the internal organs and all body tissues. Oxygen is absorbed from the blood, and "slag" (CO2) is returned instead. Blood saturated with carbon dioxide then returns to the lungs. CO2 gets released into the air volume of the lungs through the alveoli and exhaled. This process is repeated with every breath and every beat of the heart. When a person holds his breath, it leads to the oxygen content in the blood falling, because there is no breathing. But the level of CO2 is still increasing, because the heart continues to pump the blood, and tissues of the body continue to suck out the remaining oxygen from the blood and return carbon dioxide. As a result, the level of O2 in the blood falls, and the level of CO2 grows.

Static

The brain, being the chief regulator of everything in our body, reacts differently to each of these indicators. If the oxygen level in the blood drops below a certain level, a person loses consciousness. That is why there are oxygen masks in the cabins of planes, of which passengers are told during the pre-flight briefings. Aircraft's depressurisation may lead to falling oxygen level in the air, and the crew really doesn't want a lot of unconscious bodies on board. Yet in one movie this method was used to neutralise the terrorists: the captain lowered the oxygen content in the passenger's cabin, and all the passengers, including the terrorists, lost consciousness. The brain reacts even more interestingly to increasing CO2 content in the blood: when the level of CO2 rises to a certain level, the brain gives the command to inhale.

Probably everyone at least once tried to hold his breath. If you did, it most likely was like this: at first you felt quite comfortable and there was no urge to breathe, then the discomfort increased, then more and more, and finally the urge to breathe became so strong that it could not be ignored any longer and you took a breath. That was the reaction to the saturation of the blood with carbon dioxide. Correct pre-breath-holding ventilation, relaxation, and the "detached" state of mind help to soften the uncomfortable sensations.

That is how it was for me on that day. The first phase of breath-holding brought the sensation of nirvana. My body was relaxed, my brain was clear of any thoughts, and I did not need to breathe at all. Then a feeling of discomfort and a creeping urge to breathe came. After that I no longer could "detach" my mind. At that point, Julia asked me to open my eyes and focus on something at the bottom to think about the negative sensations as little as possible. The first serious signal – involuntary contraction of the diaphragm. That means it's time to breathe. Strictly speaking, one can go further, suppressing the urge to breathe by willpower. Experienced athletes do that, but I don't think everyone should. Freediving should be filled with pleasant experiences, joy and serenity, rather than discomfort. Moreover, an athlete with a strong will can suppress the urge to breathe for too long, the oxygen level can drop below a critical point, and he can lose consciousness. That happens often in competitions where athletes go all out. And that is why you mustn't ever do a static breath-holding in the water alone without the supervision of experienced instructors: if something goes wrong, there will be no one to save you.

Julia is timing our static

When I raised my head from the water and took a breath, I saw Julia standing over me with a watch in her hand. She asked whether I did this before and what was my best result. I tried to remember and said that I did not remember exactly but I thought I would be able to do two and a half minutes, although not on the first attempt and not every time. Her answer stunned me: "You already did it." My first result was 2:40. I did not even know what to think about it. Then we began to breathe again and prepare for the second attempt. The diving reflexes of the body do not kick in at once; hence the second breath-hold is usually longer than the first. The third is yet longer, but after that the breath-holding times do not usually increase. That's why three to four attempts are made. The second time I did three minutes. On the third – a little less than three – something went wrong for me. I realised that I could not fully relax my neck muscles and, besides, began freezing slightly. Julia said that I had done enough for that day, but if I wanted, I could make another attempt. I tried and did 3:20. When I was told about that, I was only able to say: "I think I won't be able to sleep tonight again!" I surprised myself, oh yes. I did not know that I could achieve such results, moreover, to do it easily and without any tension. And it wasn't just me – all the beginners surprised themselves. Everyone did more than 2:30. And Olga, a girl who never dived before, did 3:00.

I've always wondered how it happens that all the sport records are eventually beaten. Is indeed human potential increasing with every Olympic Games? But now I am even more interested how we, ordinary people with virtually no technique and no training, have shown such results. And I can see only one plausible answer: we humans have no idea what we are capable of.

The fourth day to be continued...

The text and the photos © 2010 Sergey Stadnik

Freediving in the Philippines. Day 3

2011-01-27T08:40:00.006+11:00

The next day, having arrived at Club Serena at 8 am, I discovered that the yoga had already started. I asked, and it turned out it started at 6:15. Oops! We agreed that I would come at 10 and I went "home" for breakfast.

Sea view from "Blue Orchid"

On that day we had a boat trip planned. Since I got cold on the previous day without a wetsuit, I finally decided to suit up. However, I reasoned that my open cell wetsuit would be too thick for the tropical water. I asked Mark, the manager of my hotel, if there was an appropriate wetsuit I could borrow. He nodded and answered that I could choose from the suits for hire in the dive shop. I chose the ordinary 3mm steamer that seemed just right.

Table of contents:

Freedivers, as well as scuba divers, wear light wetsuits when diving in warm waters. These suits are made of neoprene – spongy rubber covered with fabric on both sides. Water gets under a wetsuit and, because the suit fits very tightly, cannot get out, hence creating a thin layer of water between the rubber and the skin. That layer of water is warmed by the body, and the spongy rubber helps to retain that warmth. Thus, strictly speaking, a wetsuit does not warm – it prevents the loss of body heat. Open cell wetsuits are a bit different. They have no inner fabric lining - spongy rubber adheres directly to the skin. That leads to a double effect. Firstly, a layer of water between the skin and the rubber is much thinner, since there is no fabric that sucks in the water. And secondly, the pores of rubber retain tiny air bubbles, which conduct heat worse than water. Consequently, open cell wetsuits are warmer than ordinary ones. A 3mm open cell wetsuit is as warm as ordinary 5mm, yet thinner.

Boarding the boats

When I arrived at Club Serena at 10, I saw two boats already waiting for us offshore. In the meantime all our folk had crowded around a tall stranger. The man's name was Wolfgang, and he was a local freediving instructor. He himself was from Austria but now lived permanently in the Philippines. He was a business partner at Club Serena resort and was responsible for its dive shop. Wolfgang was going to show us the best dive sites and help with the diving equipment. After a short discussion we all boarded the boats, and after just half an hour arrived at our first destination.

The first item on the agenda for the day was, again, deep diving. We dropped the ropes to the bottom, and then Julia divided us into groups. She herself led the team of the advanced divers, while our group of four beginners was assigned to another instructor - Oksana. The tasks were still the same as on the previous day: to do a correct dive-in, then pull ourselves down the rope by hands. The guys explained to me that they started with that every time - it helped to switch on the "diving reflexes". After a few dives Oksana told me that I could start finning. I began to dive and I felt that I did it better than on the previous day. And I wasn’t the only one - we all did better. As for me, the rope was giving me a lot of trouble. I have never dived along the line, as freedivers do. As I said, a freediver doesn't look down while diving, so it necessary to begin the dive so that the rope is in front of your eyes, and then follow it straight down, without losing sight of it. I just couldn't do that. I had to spin underwater and look for a rope, expending precious energy, and then I was still losing it and was carried away somewhere to the side. The snorkel was giving me problems too. I used to dive with a snorkel fastened to the side of the mask and not release the mouthpiece. That allowed me to breathe comfortably on the surface before diving, and upon surfacing I would just blow water from the snorkel by exhaling sharply. But the snorkel sticking out on the side of the head creates additional drag in the water and, thus, consumes energy. In addition, if a diver holds the mouthpiece in his mouth, he instinctively squeezes the jaw, creating an unnecessary muscle tension. And finally, a sharp exhalation after a deep dive may lead to a blackout. Therefore, a freediver going for a deep dive does not attach the snorkel to the mask. He breathes at the surface holding it in his hand, then hands it over to a partner and dives without it. So, my snorkel was giving me troubles: it had a pivot joint, and when it wasn't attached to the mask, the upper end tended to twist and submerge into the water, making it impossible to breathe. Moreover, it had an annoying valve, which was getting flooded pretty often, and I had to lift my head from the water to blow the water out of the snorkel. In theory, this valve was there to allow easily purging the water, but in practice it only created more problems. After a few dives, Oksana asked me how deeply I dived. I said that I had no idea, since I had no means of measuring it. Then she took off her wrist computer and gave it to me. It turned out I was diving pretty comfortably to 15 meters, despite all my problems. Moreover, my results were gradually getting better. And the last time I dived to 24 meters. That was a surprise even for me. When I came to the Philippines, I thought I could dive to 20 meters. And on the second day I already exceeded my expectations…

Pescador Island

That concluded our training for that day. Those who were tired got over to the second boat and went back to the hotel, while all the others went on with the journey. Our second destination was Pescador Island. This is a tiny uninhabited island about 50 meters in diameter. Around the island is a beautiful coral reef, rich in marine life, and many divers come to dive there. The guys said they saw sea turtles there. We jumped into the water and the boat moved away to anchor on the opposite side of the island. And we swam towards her, exploring the reef on the way. That place was beautiful. Unfortunately, words are not enough to describe it. But the underwater photos I took turned out to be of very poor quality. I bought a cheap underwater camera for $60 and took a lot of photos with it. The camera was definitely underwater - I took it down to 15 meters and it has not leaked. However, as was expected from a cheap camera, the lens was poor, and in low light conditions underwater did not work well, and all the pictures were blurry. Julia had a large camera with underwater housing, but she was busy filming her TV project. We swam for about an hour around the island, then returned to the boat and went back to the hotel. That was the end of our diving for that day. But we still had to study some theory. That was because we hadn’t come there just to dive. There is an organisation which governs all that is associated with freediving – AIDA. That is a French acronym, meaning "International Association for the Development of Freediving". The association operates throughout the world. And anyone who wants to rightfully call himself a freediver has to complete a course and pass certain tests, including the theoretical part. In accordance with the rules of AIDA, freediving courses are conducted for multiple skill levels - from one to four stars. One star is practically just the ability to simply dive. The two-star level is more serious, which requires a contender to pass some tests; three and four stars are the advanced levels. And above those are the instructor levels. A few folks of our group were already going for three stars.

On the boat

There are books written on freediving, and it's not my goal to reproduce such a book here. I'll just give a brief overview of what freediving is. Freediving, as a breath hold diving, is not something new. People dived since ancient times to hunt for food or earn a living. The most famous cases are the Greek sponge-gatherers and the Japanese Ama divers. They dove in such ways and to such depths that it makes us wonder how they managed to stay alive. For example the Greeks dived for a particularly valuable species of sponges as deep as 80 meters. Yet the modern record of freediving began in the twentieth century. In 1949 Italian Raimondo Bucher set the first official record, submerging to 30 meters on a single breath of air. In the 60s Frenchman Jacques Mayol dived to 50 meters. At that time, the phenomenon of freediving attracted the attention of medics and scientists. Having studied the physiology of freediving, they stated that diving deeper than 50 meters was impossible - that would lead to an imminent death. As they claimed, the lungs would not stand the pressure at that depth and collapse. Human lungs are composed of very thin membranes, permeated by capillary blood vessels - the alveoli. Theoretically, under great pressure lung membranes would compress, and lungs would stop functioning. However, the doctors were wrong. The modern record for freediving is already more than 200 meters. I already talked about the reflexes sleeping in us. The freedivers' lungs are saved by yet another reflex - so-called "blood shift". Under high pressure the human brain redistributes the blood flow to internal organs. Less blood is pumped to the limbs, and a kind of separate blood cycle is formed in the chest area. Capillary blood vessels of the lungs get filled with blood, and because blood is a liquid, it is not compressible. As a result, the walls of the lung membranes become rigid and that prevents the lungs from collapsing.

Soon our first theoretical lesson was finished and we went home.

That night I could not fall asleep for a long time. The realisation of my own results didn't let me calm down. Twenty-four meters... When I came there, I knew that water was a native element for me and that I could dive, but I did not expect that I would achieve such things. Moreover, it was practically without any formal training. I was wondering what would happen next...

The end of the third day.

The text, the photos and the video © 2010 Sergey Stadnik
The music composition used in the video is Doroga V Nebo by Mashina Vremeni

Freediving in the Philippines. Day 2

2011-01-26T14:20:00.005+11:00

It's been quite some time since I wrote these lines. And, perhaps, if I were writing this now, I wouldn't write it in the same way - my views on many things changed. But re-reading it again, I decided to leave everything as it is. These are my impressions, captured in writing; they reflect what I thought and felt back then, and this is precisely why they are valuable. I learned a lot during those 12 days... But I will not jump ahead. Read on and you'll see for yourself.

Path on the beach from "Blue Orchid" to "Club Serena"

Table of contents:

Before I went to my hotel, Julia invited me to come at 7 am the next day for yoga. I promised that I'd come if I woke up, not trusting in that myself. However, the local time played a joke on me. For me, the time on the Philippines "lagged". That is, when it was noon there, it was 3 pm in Melbourne. So I woke up at 6 am and could not fall asleep any more. Since I didn't have anything else to do, I got up and went to yoga. Upon arriving at Club Serena, however, I found no one. Half an hour later the people leisurely started to appear. Judging by the testimonial evidence, the night was a success. Whiskey was followed by rum, then by something else, and then, as in the movie Hangover, no one could remember. Fortunately, nobody found a tiger in his room.

When a sufficient number gathered, the yoga started. We began with breathing and went on to exercises. I myself am an aikido black belt. A few months ago one of my friends became a yoga instructor and invited me to his class. I went there and realised that, in fact, yoga was not that different from aikido. And I can see why: the human body is the same wherever in the world we are, and all the oriental gymnastics, such as yoga, tai-chi, aikido, wushu, have the same purpose – the cognition of one’s inner self via physical exercises. After yoga I went back to my hotel for breakfast and returned to Club Serena. There, our company had already started to unpack.

Unpacking the equipment

The life of a travelling freediver isn't easy. And that is mostly because of fins. The freedivers' fins aren't ordinary. Each freediver's fin is a three-foot-long flexible carbon fiber blade with an attached foot pocket. They don't fit into a bag assembled; therefore they need to be taken apart for the transporting. Conversely, they need to be fastened together by screws before using. Monofins are even more inconvenient to carry around. A monofin is a large glass fiber blade, reminiscent of a mermaid's tail, with attached pockets for both feet. A monofin is a piece of top class freediver's equipment – they are very efficient and very powerful. However, special skills are required for monofin swimming, and not everyone can do that. When transporting, monofins are even more inconvenient than the "normal" freediving fins: they are fragile and require a special case. I don't have freediving fins myself; hence I don't have such problems.

Finally all unpacked and gathered on the beach. Julia allocated the roles for that day according to each person's level. I and three other beginners Julia assigned to herself.

She began by telling us a little theory about why people can dive while holding their breath. Without going into details, it is due to our ancestry. All mammals, even terrestrial ones, including humans, have what we call "diving reflexes". We've had them for millions of years - ever since our ancestors lived in the sea. In some mammals, as in dolphins and whales, they are more pronounced. In some, like people, they are weaker. If someone spends his entire life on land away from the sea, these reflexes never wake up. But if he starts to dive, they awaken. Freedivers have learned to awaken and develop the abilities inherent in us by nature, and that freediving records are constantly beaten only confirms that.

The theoretical part of Julia’s presentation was followed by the breathing exercises. Such exercises are one of the techniques freedivers use to develop the human abilities. Breathing is a reflex function. We don't think about how we breathe. And in our everyday lives we do not use our full lung capacity. Most people breathe with the upper part of lungs, expanding and reducing the chest. The lower part of the lungs in the stomach area remains motionless, and the air doesn't get into the lowest parts of the lungs at all.

The exercises that freedivers practice originate from yoga and are known as The Complete Breath. The Complete Breath helps utilise the entire volume of the lungs. That means more air in the lungs, hence the opportunity to dive deeper and farther.

After the breathing, everyone got suited up, i.e. put on wetsuits. As for me, on that day I was wearing not a wetsuit, but a stinger suit – a protective suit made of Lycra. A stinger suit doesn't warm, but provides protection from jellyfish and plankton.

A buoy on the water

The local guys had already placed the buoys for us beyond the reef. The reef itself stretches along the beach about 15 meters from the shore. The top of the reef is at three meters depth, but a few yards farther a vertical wall drops into the depths. The buoys were right there. A buoy is actually a life buoy on the surface, to which a thick rope is tied. That line goes vertically into the depth and the other end is attached to the load on the bottom. The line allows freedivers to dive straight down without losing orientation.

Since it was only the first lesson, the beginners, including myself, had only a few objectives. Objective 1: Start dive as efficiently as possible and without unnecessary movements. When a person holds his breath, the volume of work that he can perform is limited. Every movement causes muscle tension, hence consumes oxygen stored in the lungs and blood. Therefore, freedivers must move as efficiently as possible underwater. The correct way to begin a dive is like this:

Start lying relaxed on the water and breathing deeply through the snorkel.
Take last breath, filling your lungs fully with air. Then bend over at 90 degrees at your waist and reach down with your hands.
Raise your feet out of the water and bring your legs to the vertical position, straightening your body.
The weight of your lower body will push you down and you'll find yourself quietly sliding down.
Once your feet are underwater, start finning.

It took us some time to learn the above technique, but in the end everyone was able to do that properly.

Objective 2: Pulling with your hands only along the rope, without finning, descend as deep as it will be comfortable, not forgetting to equalise the pressure as you go. Because I dived before, I was familiar with equalising pressure in the ears. And it came as a surprise to me that there were people who didn't know how to do that.

The human ear consists of the outer ear, middle ear and inner ear. Between the outer and middle ear is the eardrum. We hear sounds because the sound waves exert pressure on the eardrum; it fluctuates and these fluctuations are converted by the middle ear into electric signals, which are recognised by the brain. On the surface of the earth the pressure applied to the eardrum is 1 atm (for atmosphere). The pressure increases with the depth: by 1 atm every 10 meters. Respectively, the pressure applied to the eardrum grows. If a freediver does not equalise that pressure during the descent, severe damage may be done to the eardrum; it might even tear. Luckily for us there is a way to avoid it. The middle ear is connected to the sinuses in the nose by air channels, so-called Eustachian tubes. Normally these channels are closed. But if the pressure in the sinuses increases, they open, part of the air passes into the middle ear, and the pressure on the inner side of the eardrum is equalised with the outside. That is a complicated explanation of a simple process, which probably everyone is familiar with. For example, everybody knows that ears get blocked on a plane during a descent, or even during a downhill drive in a car. This happens because the air pressure from the outside of the eardrum grows. To equalise the pressure it's enough to block the nose with a hand and "blow" air "into the ears". Doing this will direct air into the Eustachian tubes, they will open, and eardrums will pop with a click and clear. Sometimes it is enough to swallow or yawn - that also opens the Eustachian tubes. Freedivers do exactly the same thing to equalise pressure in their ears while diving. But because the water pressure increases much faster than in a plane during landing, the effect is more pronounced. Hence, they need to equalise far more often.

Some novice freedivers, especially ones who never did any diving before, find it hard to equalise. Without equalising, they start to feel discomfort, sometimes even pain, in the ears a few feet below the surface, and it gets worse the deeper they go. Nevertheless, the percentage of people who are genuinely not capable of equalising is very, very small. This may be due to clogged Eustachian tubes or sinuses, or other similar reasons. All the others can learn. Everything comes with patience and practice.

Down along the rope

I was lucky: I grew up near the sea and have been diving as long as I can remember. Therefore, I could equalise, at least in the simplest way (there are better ways practised by more experienced freedivers, but they are more complex).

But I had problems too. I used to dive looking where I was going. If a person, diving head straight down, tries to watch where he is going, which is also down, he throws back his head, thus disturbing the streamlined shape of the body. Water is 800 times denser than air, and the hydrodynamics of a human body in the water is not less important than aerodynamics of an aircraft in the air. The worse hydrodynamics is, the more energy it takes to propel yourself through the water. That is why freedivers do not throw back their heads to see where they swim. They keep the head aligned with the body and look at the vertical rope in front of their eyes.

After a few dives pulling myself down the rope I became reasonably OK in that, and Julia told me that I could start using the fins. That wasn't a problem for me. Well, except for not entirely correct finning technique, which consumed energy, hence I burned oxygen faster. I didn't know how deep I was diving – I was told later that I went to approximately 12 meters. That depth was quite comfortable for me. I could stay down there for several seconds and then calmly swim to the surface.

In the meantime, I started freezing. In between the dives a freediver lies still on the surface of the water, holding onto the buoy, resting and breathing. For some reason I decided not to put on a wetsuit that day. Despite the fact that the water temperature was 27 degrees C, cold waves were rolling on me every few seconds. I was shivering and, as a result, couldn't relax.

After the exercises we swam on the reef for a while, then I got out of the water and went to my hotel for a dinner. After dinner I decided that it would be good to write it all down while my impressions were fresh. I sat down and began to write the notes you are reading now.

The end of the second day.

The text © 2010 Sergey Stadnik
The photos © 2010 Sergey Stadnik, Vasily Avseenko

Freediving in the Philippines. Day 1

2011-01-25T18:56:00.010+11:00

In March 2010 I went to Cebu Island of the Philippines with a group of Russian freedivers. This is my diary of what happened there. It is a long story; so, sit back, relax, and enjoy the reading.

Looking at the map, I find it hard to believe that the Philippines are so far from Australia. Indeed, if there were direct flights from Australia, it would not be so far away. But, unfortunately, none of the airlines have direct flights from Melbourne to Cebu Island of the Philippines where I was going. Therefore I had to fly to Singapore first (seven hours) and from Singapore to the Philippines (four more hours). That was certainly closer than from Moscow, but still a long way. However, I should not complain. By Australian standards it is practically around the corner. I bought the tickets so that I would meet the team of Russian freedivers midway – at the Singapore airport – and then we would fly to the Philippines on the same plane. The seven-hour flight from Melbourne to Singapore was quite easy, except for the flight being delayed for an hour, and I managed to sleep almost through. Interestingly, despite the night flight (the departure from Melbourne was at 1 a.m.), the Singaporeans offered a supper immediately after take-off and climb – at 3 o'clock in the morning. I wisely declined the "supper".

Table of contents:

At the Singapore Airport

Singapore was a double shock: the size of the airport and the climate. The Singapore International Airport consists of three terminals and the adjacent multi-storey shopping mall, with trains running between the terminals. If one were planning to explore each terminal in detail, he would probably need a few hours. All the terminals are air-conditioned, the trains too. But during a short period of time when the train's doors are closing as it is leaving the station, the "outboard" air leaks through the gaps. At this point, one has an opportunity to fully evaluate Singapore's climate. I knew that the air temperature at Singapore was about 30 degrees C all year round with nearly 100 percent humidity, but I didn't really understand what it meant until I felt it.

In Singapore, I met Julia Petrik and the rest of the Russian freediving crowd, and together we boarded the plane to Cebu. However, the trip wasn't without incident. The plane made a stop en route to another island of the Philippines to disembark some passengers. The transit passengers, including us, were asked to temporarily leave the plane. Not all of our Russian folks were able to understand from the captain's announcement that we hadn't arrived at Cebu yet, and they vigorously tried to break out into the city. As a result, the whole crowd was divided into two parts: those who could understand the captain's statement (including me), and those who could not. The former were calmly relaxing in the airport lounge, while the administration of the airport was trying to catch the latter. Finally, all were recaptured, seated in the plane, and sent on the route. After another three-quarters of an hour we arrived in Cebu.

Customs and passport control at Cebu are mere formalities, and in no time we emerged from the airport's gates where our next transport was already waiting for us. We had our hotels booked at the White Beach resort, which is on Moalboal peninsula, three hours away from the airport by car. The hotel, which the rest of the guys stayed in, provided the transfer, but it turned out they didn't account for me. Everyone except me was going to "Club Serena", while I – to "Blue Orchid". These hotels are just 200 meters away from each other, but the minivan's driver flatly refused to take me, explaining that it was the particular hotel's transport and they didn't take "strangers", and besides there was no space left anyway. I didn't argue. Instead, I caught a taxi, waved my hand to the other guys, and was off.

Just as Singapore before, the Philippines shocked me. I knew that it was neither Australia nor Europe. In fact, I didn't know what I expected to see. But it shocked me anyway. According to the research I did before going there, Cebu was a large city. What can I say now? Large – yes, city – no. The landscape outside the taxi did not resemble a city at all. The best word to describe what I saw is "slums", slums three times and in the third degree. I was so stunned, I did not even try to get out the camera and shoot. The only place I saw something like that before was in "This could happen only in China" photos. Here are some of the pictures imprinted in my memory:

Children on a bike, five on one. The driver is about ten years old
Motor rickshas, everywhere and in enormous quantities. These are motorcycles with a passenger cabin hooked to one side. Motorcycles and the cabins are covered with headlights like Christmas trees.
Children, running down to the car and peering through the windows.
Everyone drives as if road markings are tentative, including driving on opposite direction lanes. Perhaps this is why everyone honks often – to avoid accidents.

Motor rickshas

If you think about it, as a matter of fact, there is nothing too shocking about it. However, after Melbourne and Singapore the contrast was simply overwhelming. It should be noted, however, that the majority of Filipinos are hospitable and sympathetic people and always willing to help. However, I still didn't have any desire to get out to the "city" and get acquainted with the local attractions. It just wasn't what I came here for.

At one point, the taxi came to a halt in a dense traffic jam. And after about twenty minutes of barely moving, we finally saw what was causing the problem. On the last day of winter the Philippines was celebrating the Mardi Gras. It was a great celebration. The grand fiesta stretched for several blocks. On both sides of the road were stalls with various kinds of food. "Everyone is invited to this celebration," explained my driver, "regardless of who they are."

By the way, I chatted to the driver. His name was Joey and he spoke English possibly better that I do. He told me that he was driving a taxi to feed his family. He had a wife and four children. His wife recently finished studying and worked as a chemical engineer for the government. (The Philippine's government subsidises the training of young professionals.)

On my way to Moal Boal

The radio was on in the car and, to my amusement, the broadcast was in English, even advertising. Moreover, almost all the signs I saw during the trip were in English. I asked Joey and he explained that all Filipinos learn English at school, therefore almost all of them speak it, although not all fluently.

Eventually we reached the hotel. We drove for three and a half hours, but covered the distance of just over a hundred kilometres. That was due to the fairly dense traffic.

At the hotel I was greeted by a European-looking man, who introduced himself as Mark, the hotel's manager. He showed me to my room, wished me a good stay, and asked me if I wanted to order dinner. But dinner at the hotel wasn’t in my plans for that evening – I was going to visit the rest of the guys at "Club Serena" and have dinner there with them. I asked Mark how to get there, and he said that I just had to follow the path along the beach. I unpacked my stuff, took a shower, and set off.

"Blue Orchid"

At half past six in the evening the sun was switched off in the Philippines. It was getting dark so fast that I did not have time to get around. I tried to find a path Mark told me about, but realised that under the moonlight the chance of success was slim. I returned to the hotel and complained to Mark. With a smile, he fetched a small flashlight and handed it over to me. Armed with it, I made a second attempt. It turned out that I just had to go down to the beach and walk along the water's edge. After 10 minutes of stomping on the sand I arrived at "Club Serena", where I immediately headed to the restaurant, not doubting that everyone was already sitting having their dinner. However, the restaurant was empty. Surprised, I ordered a dinner and went to try to figure out where everyone was. Approaching the hotel's gate, I spotted a minivan from which our crowd was emerging. They were in a bad mood. It turned out that they had not travelled without incident either. Someone miscalculated, and they didn't fit into the minivan that was sent after them to the airport. As a result, they had to wait for another one, and therefore arrived two hours later than I did. The act of arrival was followed by the mess of accommodating. All rooms in "Club Serena" are different and are located in houses of various configurations. And our freedivers simply could not decide who stayed where. At the same time the hotel's staff tried to find when we were going to have dinner and collect orders. However, everybody was too busy to study the menu. I had to take the initiative myself. I chose a couple of dishes from the menu, which I reckoned would suit everyone, called the girl from the staff, and pointed at the lines I chose and said: "Eight of this and eight of that." And the issue was resolved.

The dinner was served an hour and a half later in a gazebo on the beach. It was our first night there, and it started traditionally with the introduction of everyone to each other, and ended the same traditional way – drinking whiskey and rum. At around midnight I said goodbye to everyone and went back to my hotel.

"Club Serena"

More precisely, I tried to go. I walked a little bit down the beach and realised that the rising tide made my return impossible: the beach was completely flooded and I could get back only by swimming. I had to go back to Club Serena to ask what I could do. When I explained my problem to a bartender, a woman sitting next to me turned towards me. She introduced herself, and it turned out she was the owner of the hotel. Laughing, she announced that I was certainly in trouble. The hotels really are very close – just 10 minutes walk along the beach. And there is a road that links them. However, it is not straight, and walking along it from one hotel to another is not possible. However, she said she would help me and give me a lift. She called her driver, and while we waited, we chatted. I explained who I was and what I was doing there and asked her if she knew Michael, the owner of "Blue Orchid". She replied that she knew Michael well. He was the godfather of her daughter, or maybe niece, or something like that, and she was godmother to one of his relatives. It proved too complex for poor me to grasp the difficult relationship of the owners of the Philippine hotels. Finally the driver arrived and we set off.

I find it difficult to understand how it was possible to pave the way between two points located 10 minutes walk from each other so that it takes 15 minutes to drive between them, but it is a fact. And I realised that the owner was right – I couldn't walk there. Finally I returned to my hotel, collapsed on the bed, and immediately fell asleep.

The end of the first day.

The text © 2010 Sergey Stadnik
The photos © 2010 Sergey Stadnik, Vasily Avseenko

Coming Revolution

2010-08-27T08:39:00.001+10:00

Soon a small black box will enter our living rooms, and that will change the way we spend time in front of TVs forever. It will happen on Nov. 4, 2010, and the name of this phenomenon is Kinect.

In my student days I was an avid gamer and has played virtually all "big" games that came out for PC, luckily for me those days it wasn't such a flood as now. And I remember well the events that changed the game industry as we knew it. Those milestones were:

Doom - the first popular first-person shooter, 1993;
3dfx Voodoo - the first 3D accelerator, 1996;
Nvidia GeForce 256 - the first 3D accelerator with integrated geometry GPU, 1999.

After that, I stopped actively playing games did not follow the gaming news. And returning sporadically into the game world I was discovering that nothing actually has changed. Well, the resolution was higher, graphics better and explosions more colourful. But the gameplay still remained the same - defined by Doom at the beginning of 90s. Of the remarkable events only the release of Nintendo Wii in 2006 comes to mind, which changed our perception of computer games. They were no longer something available only to nerds. Now the whole family could play and, more importantly, while moving rather than sitting still. Perhaps it was then, when Microsoft saw that and decided to take the idea to a new level.

Kinect is a small box connected to the Xbox 360. It has 2 cameras that watch the player, detect the position of his body and movement, and thereby enable you to control events on the screen. Motion Control in a pure form – simple and brilliant. No controllers, no wires. According to Microsoft's statements, one Kinect can completely digitise movements of two players and track the positions of four more. The players may be standing or sitting. In addition, Kinect has multi-array microphone through which it can recognise the voice of his "master" and obey his orders.

Microsoft presented Kinect a year ago at E3 exhibition, then it carried the working title "Project Natal". And immediately it was clear that it would be a revolution, if only Microsoft would be able to deliver on promises. Now, when Kinect is very close to the release, Microsoft has distributed sample devices to leading gaming magazines. And now we can say firmly - Microsoft succeeded. According to the lucky ones who played with Kinect, watching first time the character on the screen waiving its hands in coordination with you movements is fascinating. Motion Control is not perfect, but still very good.

This is what a gameplay with Kinect looks like:

I predict that Kinect will be a huge hit. It along with the new Xbox 360 will take the market by storm. Potential customers will have to stand in a queue for hours to buy it. And for some time after launch it will not be possible just to walk into a store and buy one, as it is now impossible to buy an iPhone 4. Neither Sony, nor Nintendo has anything comparable.

So, we are on the eve of the revolution. Now it is the turn of gaming companies to help us fully explore this bright new world.

Don't mess with LIKE

2009-11-06T13:21:00.005+11:00

Oh boy, It looks like it's time to change the title of this blog to "A hundred ways you can screw up with Oracle". I may need a new domain name, something flashy. www.oraclewtf.com would be fine. Let me see, it is currently available. I wonder how fast cyber-squatters will jump in and snatch it now when I pronounced it. Then they will blackmail me demanding a outrageous ransom or else... (insert evil face here)

On second thought, no. I don't want to turn this blog into an Oracle-specific. There are already enough Oracle blogs out there. In fact, I think there are more of them than Oracle professionals who would read them. I don't want to bring yet another one to the world just for the sake of it. Heck, it's my place and I'm going to write about whatever I want. Hence the title, Random Thoughts.

Ok, kids, take your places. Today's lesson is (surprise, surprise!) about Oracle. We already discussed a few ways we can screw up with dates. Today we will talk about numbers. On the surface numbers look like pretty innocent data type. But once you dive a little deeper... Beware! Fearful creatures lurk beneath. And if you are not careful, they will snatch you in no time.

Take a look at this Stackoverflow.com question by James Collins.
James had a problem, the following query was slow:

SELECT a1.*
FROM   people a1
WHERE  a1.ID LIKE '119%'
       AND ROWNUM < 5

Despite column A1.ID was indexed, the index wasn't used and the explain plan looked like this:

SELECT STATEMENT ALL_ROWS
Cost: 67 Bytes: 2,592 Cardinality: 4 2 COUNT STOPKEY 1 TABLE ACCESS FULL TABLE people
Cost: 67 Bytes: 3,240 Cardinality: 5

James was wondering why. Well, the key to the issue lies, as it often happens with Oracle, in an implicit data type conversion. Because Oracle is capable to perform automatic data conversions in certain cases, it sometimes does that without you knowing. And as a result, performance may suffer or code may behave not exactly like you expect.

In our case that happened because ID column was NUMBER. You see, LIKE pattern-matching condition expects to see character types as both left-hand and right-hand operands. When it encounters a NUMBER, it implicitly converts it to VARCHAR2. Hence, that query was basically silently rewritten to this:

SELECT a1.*
FROM   people a1
WHERE  To_char(a1.ID) LIKE '119%'
       AND ROWNUM < 5

That was bad for 2 reasons:

The conversion was executed for every row, which was slow;
Because of a function (though implicit) in a WHERE predicate, Oracle was unable to use the index on A1.ID column.

If you came across a problem like that, there is a number of ways to resolve it. Some of the possible options are:

Create a function-based index on A1.ID column:

CREATE INDEX people_idx5 ON people (To_char(ID));

If you need to match records on first 3 characters of ID column, create another column of type NUMBER containing just these 3 characters and use a plain = operator on it.

Create a separate column ID_CHAR of type VARCHAR2 and fill it with TO_CHAR(id). Index it and use instead of ID in your WHERE condition.
Or, as David Aldridge pointed out: "It might also be possible to rewrite the predicate as ID BETWEEN 1190000 and 1199999, if the values are all of the same order of magnitude. Or if they're not then ID = 119 OR ID BETWEEN 1190 and 1199 etc.."

Of course if you choose to create an additional column based on existing ID column, you need to keep those 2 synchronized. You can do that in batch as a single UPDATE, or in an ON-UPDATE trigger, or add that column to the appropriate INSERT and UPDATE statements in your code.

James choose to create a function-based index and it worked like a charm.

SYSDATE confusions

2009-11-04T17:04:00.007+11:00

SYSDATE is one of the most commonly used Oracle functions. Indeed, whenever you need the current date or time, you just type SYSDATE and you're done. However, sometimes it's not all that simple. There are a few confusions associated with SYSDATE that are pretty common and, if not understood, can cause a lot of damage.

First of all, SYSDATE returns not just current date, but date and time combined. More precisely, the current date and time down to a second. If just a date is needed, TRUNC function has to be applied, that is, TRUNC(SYSDATE). For a sake of a good database design, date should not be confused with date/time. For example, if a column in a table is called “transaction_date”, it would be natural for it to contain a date, but not date/time. That may lead to a major confusion. Let's imagine there is a table BANK_TRANSACTIONS containing the following fields:

txn_no     INTEGER,
txn_amount NUMBER(14,2),
txn_date   DATE

The last field is of the most interest to us. Apparently its data type is “DATE”, but is it a date or date/time? We can't tell by just looking at the table definition. Nonetheless, it is a very important thing to know. A common case for using DATE columns is including them in date range queries. Forexample, if we wanted to get all the bank transactions from 1 January 2009 to 31 July 2009 we could write this:

SELECT txn_no,
       txn_amount
FROM   bank_transactions
WHERE  txn_date BETWEEN To_date('01-JAN-2009','DD-MON-YYYY')
                    AND To_date('31-JUL-2009','DD-MON-YYYY')

And that would be fine if TXN_DATE were a date column. But if it is a date/time, we would just have missed a whole day worth of data. And it is because, as I said, DATE data type can hold date/time down to a second. That means that for 31 July 2009 it could hold values ranging from 0:00am to 11:59pm. But because TO_DATE('31-JUL-2009', 'DD-MON-YYYY') is basically an equivalent to TO_DATE('31-JUL-2009 00:00:00', 'DD-MON-YYYY HH24:MI:SS'), all the transactions happened after 0:00am on 31 July 2009 would be missed out.

That kind of mistake is pretty common. Sometimes it's hard to tell by just looking at the data whether a particular DATE column can have date portion. Even if all the values in there are rounded to 0:00 hours, that doesn't mean that a different time value can't appear there in the future. The data dictionary can't help us here either – DATE type is always the same whether it contains time or not. (By the way, Oracle recommends using TIMESTAMP type for new projects, but that is a whole different story.)

If you are working with an existing table and you are not sure, you can use a fool-proof method like this:

SELECT txn_no,
       txn_amount
FROM   bank_transactions
WHERE  txn_date BETWEEN To_date('01-JAN-2009','DD-MON-YYYY')
                    AND To_date('31-JUL-2009','DD-MON-YYYY') + 1 – 1/24/3600

“+1 – 1/24/3600” here means “Plus 1 day minus 1 second”. That is because “1” in DATE type means “1 day”, “1/24” - 1 hour, and there are 3600 seconds in an hour.

The above expression will retrieve all the transactions from “01 January 2009 0:00am” to “31 July 2009 0:00am plus 1 day minus 1 second”, i.e. to “31 July 2009 23:59pm”.

If you are charged with designing an application and need to create a table with a DATE column, it is worth to keep yourself and others from future confusions by a simple trick: name columns that only contain date portions as “_DATE” and add “_TIME” to the name of the columns that you know will contain time components. In our case it would be prudent to call the date/time column TXN_DATE_TIME.

The second issue I'd like to discuss is much more subtle, but can do even more damage.

Imagine that you are charged with developing a report that returns all the transaction for the previous month. It looks like a job for SYSDATE! You fetch your trusty keyboard and after a few minutes of typing you come up with something like this:

SELECT txn_no,
       txn_amount
FROM   bank_transactions
WHERE  txn_date BETWEEN Last_day(Add_months(Trunc(SYSDATE),-2)) + 1
                    AND Last_day(Add_months(Trunc(SYSDATE),-1))

You create a few lines in BANK_TRANSACTIONS table, run a few unit tests to make sure your code works and check it into the source control. Job done! You congratulate yourself on the productive work and spend the rest of the day reading your friends' blogs and dreaming about your next vacation. And the next day you move on to another task and get as busy as ever.

After some time, which may be a few days or months, depending on the pace of the project, the code you wrote gets migrated into the UAT environment. And a task force of a few testers and end users is assigned to test the report you wrote. And as it often happens in UAT, they are going to test in on real data they extracted from the production system – that is, the last year's data.

Got it? Last year's.

The final stages of testing, such as UAT, have to prove that the system does what it is expected to do in conditions that resemble the production as closely as possible. And the best way to do that is to test it on the retrospective production data – the data that is proven. That makes it possible to compare the outcome to the actual production system, and thus, prove or disprove that the new system works.

That sounds reasonable. But one of the implications for you is that BANK_TRANSACTIONS table is not going to contain previous month's transactions. Hence, your report will be blank. You can't rewind back time because you hard-coded SYSDATE, which has only one meaning – “right now”. Test failed.

If you have known that when you wrote it, you wouldn't have used the SYSDATE. You would use a parameter, something like v_run_date, which you could set to whatever date you wanted. And that would do. Well, now you know.

Make it beautiful

2009-10-02T08:54:00.002+10:00

You only need a single look at Sydney Opera House to recognise that it is a work of art. Any masterpiece is like that – you don't need to do a throughout examination of Mona Lisa's smile to realise its beauty – you see it instantly. Perfection needs no explanation, it works on subconscious level. The same applies to the software engineering too. Great code always looks good. It is always carefully formatted, indented and commented. By just looking at it you can tell that it is a work of art. Such code will always work, do what it is supposed to do and have a very few bugs. Because whoever wrote that code cared a lot about it. And you can safely assume that if anyone has put a lot of effort into making the code looking good, he has put at least as much effort into designing and debugging it. What is even more important, carefully carved code is easier to maintain. In modern software projects any single procedure gets tweaked and rewritten tens of times. If you are a programmer, good chances that even in a project that you work on right now you inherited some code that was written years ago, maybe from people who long left the company. And when you finish with it, it will not be the end of the story – the code will be passed to QA and finally to the production support. And then the cycle will start again. Hence, whatever you program, it's not just about you. You don't know how many people will be looking into your code trying to make sense of it. And you can help them immensely by making it is easy to read and understand now. Whether you will be remembered as a good programmer or cursed depends on it. So, you made an effort to write the code that works. Now make an extra step – make it beautiful.

Quest for the perfect reader is almost over

2009-09-09T11:47:00.001+10:00

Those who know me know that I've been searching for a perfect ebook reader device for years. I've used mobile phones, Palm PDAs, pocket PCs, laptops... About 7 years ago I got excited about prospects of E-Ink technology, promising to deliver just what I needed. Unfortunately, E-Ink has turned out to be utter disappointment, so far delivering little but bold promises. It took years and years for the first E-Ink devices to turn up on the market. A few years ago I finally got my hands onto Sony PRS-500 E-Ink reader. Got disappointed with it after a week and sold it. A year ago I bought another E-Ink reader - that time BeBook. I still have it, but now my wife uses it. And I've got myself something better. That is iPhone. Don't get me wrong. I still like E-Ink readers. But even after all those years E-Ink remains to be a promising technology. Guys, it's about time to deliver on promises. Maybe one day... But now, E-Ink has more cons than pros: devices are expensive, screens are slow, the screen contrast is poor. And versatility is even poorer - every E-Ink reader is practically useless for anything but reading, making you carry yet another device in your bag. And if all those weren't enough, many manufacturers lock the devices to just a few supported DRM-enabled book formats (this is for you, Amazon). In few short years, iPhone delivered what E-Ink failed in decade. The truth is, the iPhone's screen is brilliant. I don't know how they did it, but it's bright, highly contast and it (almost) doesn't fade in sunlight. Yes, it's resolution is not as high as of some VGA PDAs and laptops, but it still looks better than any other LCD screen I've seen. Reading from that screen is a pleasure. Honestly, if I am provided a choice to read from either E-Ink (in its current state) and iPhone's LCD, I'd probably choose iPhone. And unlike the dedicated readers, iPhone is immensely versatile. I don't know the statistics, but it's got to be the most popular mobile software platform out there. Thousands and thousands of software titles are available. And there is no problems with ebook types either - Software like Stanza and Calibre make reading almost any kind of book a simple task. All in all, for all of you who has been waiting for a perfect reader - the wait is almost over. iPhone has delivered yet another revolution. Now is the time for a major publishing houses to wake up.

How to get a root password

2009-07-26T17:48:00.001+10:00

It's been a month since I started playing an involving adventure game "Get a root password for a weekend" with a very large multinational consulting company. That quest requires carrying out a complex sequence of actions, each of which is unknown in advance. A single error leads to a failure and necessity to start all over again. Do not pass Go, do not collect $200. Now I am almost through 2nd attempt. And I almost failed again. So, to get a root password you have to:

No less than in 2 weeks before day "D" create a change docket in a change management system.
Fill a couple of 15-pages documents, describing in details what we need to do, why and how.
Obtain approvals from our and their management.
Obtain sign-offs from the downstream systems, even the ones that would not be affected.
Attach all the approvals to the change docket.
Create a task to issue a temporary root password to us.
Send a request to the service delivery manager, asking to approve the task and assign in to a responsible person.
Attend the Change Review Board and get the change approved.
Find out that the task assigned to a wrong group. Reassign.
Find out that in order to get a root password you need to fill a form.
Obtain the form from a Security group.
Fill the form.
Get the form signed by 3 different people in 3 different buildings.
Submit the form.
In a few days get a reply from the Security group, telling that the form was filled incorrectly - a tick was put into a different box.
Fill the form again.
Get the form signed by 3 different people in 3 different buildings.
Submit the form.
After a few day's silence, start nagging the Service Delivery Manager.
Find out that another Security group is responsible for granting root passwords.
Reassign the task to the new group and forward the form to them.
After a few day's silence, start nagging the Service Delivery Manager.
Find out that yet another User Admin Security Group is responsible for granting the root passwords.
Reassign the task to the new group and forward the form to them.
Find out that the submitted form is outdated. The User Admin Security Group no longer accepts outdated forms. (The form that those guys themselves sent 3 weeks ago was outdated).
Download the new form. The difference with the old one is just that the checkboxes are positioned differently.
Fill the form again.
Get the form signed.
Submit the form.
Find out that the form hasn't changed for the last 4 years.

**** Now I think that those guys are actually Vogons.

“They wouldn't even lift a finger to save their own grandmothers from the Ravenous Bugblatter Beast of Traal without orders signed in triplicate, sent in, sent back, queried, lost, found, subjected to public inquiry, lost again, and finally buried in soft peat for three months and recycled as firelighters." The Hitchhiker's Guide to the Galaxy by Douglas Adams

Date conversion in Oracle part 2

2009-05-18T18:02:00.010+10:00

It's a follow-up to the previous post. As it turned out, implicit date conversions may also prevent Oracle from doing the partition pruning. For example, if you have a table INVOICES with a range partition on INVOICE_DATE field, then expression

SELECT
...
WHERE invoice_date >= '01-MAR-09'
  AND invoice_date <  '02-MAR-09'

will not perform the partition pruning, whereas

SELECT
...
WHERE invoice_date >= TO_DATE('01/03/2009', 'DD/MM/YYYY')
 AND invoice_date <  TO_DATE('02/03/2009', 'DD/MM/YYYY')

will. Because the efficiency of partition pruning is usually why partitioning is used in the first place, the choice is obvious. But after all, I’d use

SELECT
...
WHERE invoice_date BETWEEN TO_DATE( '01/03/2009', 'DD/MM/YYYY')
                      AND TO_DATE( '01/03/2009', 'DD/MM/YYYY') + 1 - 1/24/3600

,since BETWEEN operation is specifically tailored for such situations. "1/24/3600" here represents 1 second, and the whole statement should be read as "From 01 March 2009 0:00am to 01 March 2009 11:59pm".

Date conversions in Oracle

2009-05-13T17:28:00.008+10:00

When I was going through PL/SQL procedures written by some of my colleagues, I noticed a few mistakes made around the Oracle’s date conversion functions. There are some peculiarities about those functions that I thought everyone knew about. But I reckon if I write about it, it may help others to avoid such mistakes. I also allowed myself to outline a few rules that, if you adhere to them, will help you to write better programmes.

There are 2 functions in Oracle to convert strings to dates and back.

The first one is TO_DATE – it takes a string parameter and returns a date. Ok, it’s actually a date/time combination enclosed into a single data type – Oracle’s DATE.

The second one is TO_CHAR – does the opposite: it takes date/time as Oracle’s DATE data type and converts it to string.

Actually, these functions are bit more complex than that, but for our purpose that will do. What’s important to understand here is the distinction between date as a DATE data type and its string representation.

For example, when you type ’01-APR-09’ in the procedure’s text, that’s a string, representing a date. Pay attention here: although you meant a date, Oracle sees a string. For Oracle everything that is enclosed in single quotation marks is a string. To make it a date, we need to convert this string to a DATE data type. Such conversion can be carried out by 2 possible ways: explicitly and implicitly.

Explicit conversion is when we apply the TO_DATE function to the string:

v_date DATE;
v_date := TO_DATE('01/04/2009', 'DD/MM/YYYY');

Now v_date is a date, representing April 1^st, 2009.

Implicit conversion is when we let Oracle to perform the conversion:

v_date DATE;
v_date := '01-APR-09';

It has the same effect. Every time Oracle sees a string in place where it expects a date, it is smart enough to perform the conversion for us. "Well", you may think, - "That’s great. Oracle does it all for us, so we don’t have to do it. Life is easier, let’s go for another coffee break".

Not quite.

You see, when Oracle does such implicit conversion, it relies on some assumptions. If you read the documentation for TO_DATE and TO_CHAR functions, you’ll find that they take another optional parameter – the date format. That format tells Oracle how the string representing the date/time should be treated. If the format parameter is not specified, it is taken from NLS_DATE_FORMAT Oracle parameter. Here’s the crux: We can’t assume that this parameter will be the same on all Oracle systems. Although it is ‘DD-MON-RR’ by default and it is left like that on most Oracle systems, we can’t assume that it’s going to be like this always and everywhere. And if you rely on implicit date conversions and some DBA changes NLS_DATE_FORMAT parameter – WHAM! – All your programs will stop working.

So, a good practice and rule of thumb for you should be:

Never ever rely on implicit date conversions!Whenever you need to convert date to string or vice versa, use an appropriate TO_DATE or TO_CHAR function and always specify a date format.

Just like this:

v_date DATE;
v_date := TO_DATE('01/04/2009', 'DD/MM/YYYY');

The danger of NLS_DATE_FORMAT being changed is the biggest threat but not the only one.

Pay attention to the default date format I provided just above – ‘DD/MM/RR’. Do you notice anything suspicious? The year is 2 digits. Here Oracle tries to be smartass and tries to guess whether you mean XX or XXI century. Your only hope that it can figure out what you meant and doesn’t make a mistake. But if it mistakes – oops, welcome back the Millennium Bug. This brings us to the second rule:

Don’t be a curmudgeon – always specify the 4-digit year.

Another dangerous programming technique is trying to convert Date to Date where no conversion is necessary.

Let’s have a look at the following example, or should I say a puzzle?

DECLARE
   v_date     DATE := '01-APR-09';
   v_date_2   DATE := TO_DATE (v_date, 'DD/MM/YYYY');
BEGIN
   dbms_output.put_line (TO_CHAR (v_date_2, 'DD/MM/YYYY'));
END;

Try to guess what will be printed as a result.

If you think ‘01/04/2009’, you’ve just screwed your business critical application and have sent it two thousand years back in time. In fact, you’ll get ‘01/04/0009’.

This is where it all goes bad:

v_date_2   DATE := TO_DATE (v_date, 'DD/MM/YYYY');

And here’s why:

The first thing Oracle tries to do is to execute TO_DATE function. There is only one TO_DATE function in Oracle – the one that takes a string and converts it to a date. Despite we know that v_date is not a string, Oracle still proceeds with its logic. If you run this code, it won’t produce an error. Oracle successfully convinces itself that it sees a String where it has a Date. That happens because Oracle is able to implicitly convert that date to a string, effectively turning that line into

v_date_2   DATE := TO_DATE (TO_CHAR(v_date), 'DD/MM/YYYY');

But, as we’ve already learned, implicit date to string conversions are performed using the date format recorded in NLS_DATE_FORMAT Oracle parameter, which is by default set to ‘DD-MM-RR’. Hence, what Oracle effectively does is this:

v_date_2   DATE := TO_DATE (TO_CHAR(v_date, 'DD-MM-RR'), 'DD/MM/YYYY');

Can you spot the error already? The date formats are inconsistent! This is what you get when you don’t pay attention to the details.

So, here comes rule 3:

Avoid unnecessary conversions. Never convert dates to dates.

If you think that all this stuff is pretty confusing, that's because it indeed is. The good news is that you can avoid the confusion altogether by learning to program in a more clear, more concise way. That is a foundation of a good programming style.

Role play modelling

2008-11-06T15:18:00.002+11:00

Virtually every software development methodology stresses a need for specifying how the software end product is expected to work before starting the programming. But the truth is that writing specifications is boring. And most programmers, being lazy people (in good meaning of "lazy". Yes, I believe there is a good meaning) try to avoid boring work. So, when the specs are written, they are often incomplete and don't cover all the possible scenarios. Moreover, as the requirements change, these specs become outdated and, hence, even less useful. I wonder if there is a way to replace the boring specs with something which is fun. One possible way to go may be a "Role play-style modelling". Just think about it. Usually software product consists of a number of modules communicating to each other. Each module does a specific task. In a typical software project, different developers are assigned to implement different modules. Now imaging that before diving into coding, you have a kind of a role-playing game, where each of the programmers is actually pretending to be a module he is going to program. It goes like that:

(Dave is a module that reads an XML file and converts it into a spreadsheet, Bob is a module that is responsible for taking the spreadsheet and sending it to users as an e-mail attachment) Dave: Trying to open the XML file. Wait a minute, what if it's not a well-formed XML, what am I supposed to do then? I should probably send an error message back. Ok, I read it and successfully transformed. Now I notify Bob that it's ready. Bob, we need to decide on this notification protocol. Now, it's your turn. Bob: Ok, first I need to create an e-mail. Where do we get the e-mail address and subject line from – should we ask the user? This is something to find out. Then I need to check that the e-mail address is well-formed and the subject line is not empty. Then I read the spreadsheet file Dave provided and attach it. Dave, how big this file can be? Dave: I reckon it's up to 1 Mb, but I need to clarify it. Bob: I need to find out if I need to compress it. Then I try to send the e-mail. If it is sent successfully, I report Ok status back to Dave. If it's failed, I report failure status with the error message. ... And so on.

That would give all the participants the understanding of how the end product should work. And, assuming the programmers are taking notes as they do it, every one will end up with a mini-spec just for themselves. Another advantage of such approach is that it would encourage people to discuss every possible situation and ask "what if" questions. And asking them is the most important part of the whole process. While there is at least one outstanding question, the spec is incomplete. So, after our game, Bob and Dave would depart on harassing whoever appropriate, like business analysts or even end users, to extract the answers from them. And once they have the answers, we would repeat the game again. And would do it over and over again, until everything unknown is ruled out. It sounds like a odd approach, but it just might be odd enough to work.

The recruitment landscape is changing...again

2008-10-30T12:07:00.002+11:00

A few days ago I went to a presentation by an Oracle recruiter. He talked about the ways Oracle searches for the potential candidates and and hires them. One particular thing that struck me was that Australian Oracle recruitment team does not use specialised recruitment web sites. About a decade ago, looking for a job was all about reading newspaper ads. Then along came job web sites, and the recruitment landscape changed forever. I am myself of a younger generation, and looking for a job for me was never associated with newspapers. When I look for a job, I go to a web sites such as Seek or Monster.com and search there. I take as given that all the jobs I may be interested in are posted there, either directly of through recruitment agents. This approach is more convenient for both job advertisers and seekers, because it allows them to find each other more easily. And most of the activity is concentrated around a few dominant players such as aforementioned Seek and Monster. This is because of so-called network effect: such web sites are created to connect people to each other, in our case job seekers and advertisers, and because the number of possible connections is proportional to the square of participants, the probability of "getting connected" through a large job web site is much higher than through a small one. Thus, size does matter. Indeed, if I want to find a job, the first thing I do, like Willie Sutton robbing banks because "Because that's where the money is", is look at the largest local job site, because this is where the jobs are. But this is changing. As I already said, I was surprised to hear that Australian Oracle recruiters do not use job web sites. Instead, they exploit a relatively new phenomenon of Internet social network services. Social networks benefit from network effect at the scale of magnitude comparing to the traditional job sites. This is because the network size of job sites depend on the number of job advertisers paying for placing their ads. In other words, id depends on supply of ads. And if supply side does not increase, the network will not grow. On the other hand, the growth rate of a social network is not limited by either supply or demand. As long as new members keep subscribing, network will grow. Even if they stop, the existing members will still be able to establish new connections until all the members are connected to each other. And this number, as I said before, is a square of the number of members. A good example is LinkedIn, which is effectively a tool for building a professional social network. It allows you to easily find your co-workers, provided they are registered with the site, as well as connect with potential employers. So, what is there for employers? The benefit for them is that they are able to build their network, even if they are not actively hiring. And after that, when they need it, they will be able to instantly find the right candidates through their connections. It is like having a job seekers bank at their disposals, almost like a database of resumes. But this bank will update and grow by itself. This leads us to an interesting conclusion: within this new paradigm if you're not online, you cannot be found. And if you cannot be found, you can't be hired. Just because you are outside of the network. All in all, we are witnessing a birth of a new recruitment methods. Who knows where it is going to lead us. Maybe in 5 years it will be mandatory for job seekers to have a Second Life avatar and all the interviews will be conducted in virtual reality. Australian Oracle recruitment team has a blog, they also follow LinkedIn, Twitter and MySpace networks.

The Issue of Risk

2008-10-14T00:02:00.002+11:00

Once during one of the projects I was asked what was the risk of something going wrong. I remember I answered that we, programmers, do not assess risks. We just do everything possible to prevent them. “There is no point”, I said, “to calculate the chances and the impact of a file not being in the incoming directory upon the start-up of the process if we can implement a simple check and avoid the disaster”. Needless to say, I was wrong. Nowadays I work in a bank. And one of the things I learned about banks, they all have departments responsible for managing risks. A bank in its business plays a risky game - it lends money. It is risky because there's always a possibility that it will not get them back. And banks learnt to manage these risks. They ask: "What can go wrong? What can we do to prevent that? And what can we do to minimize the impact if we won't manage to prevent it?" Software industry is much much younger than banking. But we are proud of ourselves, because we use cutting-edge technology and most modern methodologies. Yet, we haven't learnt some basic principles other industries employ for decades. We don't manage risks. I've seen a few projects screw-ups, all for various reasons: a technology chosen wasn't robust enough to support the solution, the staff's skills were not strong enough to implement the solutions, requirements were unrealistic... The cause may be different, but the result is always the same - failure, or infinite slippage of the deadline, which is the same as a failure. And in every case the failure seemed to have been unexpected. It puzzled me - why could nobody predict it? And it happens over and over again. I am a faithful reader of The Daily WTF blog. Every day it publishes failure stories like the ones I witnessed. So, if we are so smart, why does it keep happening over and over again? Because in a software project nobody asks what can go wrong. Not all risks are the same. Some risks can be assessed and eliminated. Such as a risk that the existing or planned hardware will not be able to manage the workload. This kind of risk is calculable. We can do a stress test, measure the execution time, do basic calculations and determine not only that we need a new server with more powerful CPU, but how exactly powerful it needs to be. Others are harder to predict. How would you assess a risk of your project manager being a crook and ruining a project? And, finally, there's a mother of all risks – a highly improbable event, the Black Swan, as Nassim Nicholas Taleb calls it in his book "The Black Swan: The Impact of the Highly Improbable". (I would highly recommend it to everyone who wants to learn more about risks) What, for example, is going to happen to your project if all the programmers decide to quit at the same time? Once I worked on a project that employed so called custom rules engines for performing complex batch calculations on a huge dataset - about a hundred million rows. We had a few thousand rules defined by business people, and in order to get a result we needed to apply every rule to the source dataset. As you can imagine, it was slow. Scanning a hundred million rows is not fast, especially when you need to do it a thousand times. So, a strategic decision was made to speed it up. One of our local geniuses came up with a brilliant, as he thought, idea: instead of applying a thousand rules hundred thousand times each, we will reformat the existing rules so that they form one monstrous rule, containing all thousand, which can be applied to the source dataset in one pass. And so we did. One thing, though, we didn't take into account: when combined all together, the rules formed a frankensteinian SQL expression more than 1000000 character long (that's right, more than a million). Yes, it worked, and the process became reasonably fast. But what was the price paid? Imagine that you are a support programmer. You are quite unhappy with your life, and your job in particular, because you're fed up with those stupid users and their problems. And on one evening, just as you were going to go home, you get a call. Apparently, the rules engine failed. You open the log and what do you see? A million characters long SQL and at an error message the end, saying that an error happened somewhere in there. Yep, somewhere in those million chars. You see, that's the way Oracle works. It tells you that an error has happened and tells which one (let's say, division by zero), but doesn't tell where exactly within the given SQL it has happened. So, what are you going to do, step by step? Don't know about you, but I would start writing a resignation letter. And I wasn't the only one confused. No one I asked could answer that question. You may ask, what does it have to do with risk? There is a direct connection. We had certain risk that the system being built couldn't handle the workload. The amount of that risk was known. We could calculate how much time it took to process the data set, extrapolate it to the given requirements and find out that it took 10 times more time than was acceptable. We could resolve it by buying 10 times more powerful server, or cluster of less powerful servers. In any case, the risk and the cost associated with eliminating those risks were calculable. After a strategic decision was made to solve the performance problem by much more complex rules engine, the risk became incalculable. Yes, they prevented the performance problem, but introduced another and much more serious: in a case of a single failure the system was going to go down for undefined time. Because no one would be able to fix it. And the undefined downtime would mean an unlimited loss for the business, because in a business world time is always money. So, what they did is substituted an imminent, but assessable risk, that, in fact, could be prevented, with a less probable, but potentially much more severe which that could not be assessed. I don't believe that solving a minor problem by introducing a much severe one, and hiding a possibility of a failure under the rug is a proper risk management. I'd rather called it a suicide.