Testing of Muiltiple tempdb files and its performance

Ok. We are told by Microsoft that SQL server requires the same number of tempdb data files as the number of cores. So, is this really true? In order to test this, I created a simple test case using the Microsoft OSTRESS tool. The idea is simple, we create a script that hammers the tempdb and we run them from multiple threads. First we create a log table in our monitoring database: use dbmonitor go create table tempdbStressTest (NoofFiles int, duration float) then we compose a tempdb hammering script like so: use tempdb go set nocount on create table #kkk (col1 char (7999)) declare @starttime datetime, @stoptime datetime, @i int, @noofTempdbfiles int select @noofTempdbfiles =count (*)-1 from sysfiles select @starttime =getdate() select @i=0 while @i<100000 begin insert #kkk values (replicate ('a',7999)) select @i=@i+1 end select @stoptime =getdate() insert into dbmonitor.dbo.tempdbStressTest values (@noofTempdbfiles,cast (@stoptime-@starttime as float)) drop table #kkk after all the setup, we run OSTRESS against our test server which has 4 cores Ostress -SServername -E -iD:\DBA\tempdbstresstest.sql -n20 Notice we created 20 concurrent connections. We then gradually add the number of tempdb data files. ALTER DATABASE [tempdb] ADD FILE ( NAME = N'tempdev2 ', FILENAME = N'D:\MSSQL\Data\tempdb2.ndf' , SIZE = 3072000KB , FILEGROWTH = 10%) GO USE [master] GO ALTER DATABASE [tempdb] ADD FILE ( NAME = N'tempdev3 ', FILENAME = N'D:\MSSQL\Data\tempdb3.ndf' , SIZE = 3072000KB , FILEGROWTH = 10%) GO USE [master] GO ALTER DATABASE [tempdb] ADD FILE ( NAME = N'tempdev1 ', FILENAME = N'D:\MSSQL\Data\tempdb1.ndf' , SIZE = 3072000KB , FILEGROWTH = 10%) GO USE [master] GO ALTER DATABASE [tempdb] ADD FILE ( NAME = N'tempdev0', FILENAME = N'D:\MSSQL\Data\tempdb.ndf' , SIZE = 3072000KB , FILEGROWTH = 10%) GO we restart the SQL server each time we add a file. Note that we add the same size files for all data files. we then run the reporting query as follows: select avg(duration)*1000, NoofFiles from dbmonitor.dbo.tempdbStressTest group by NoofFiles And the result is astounding.

Wu Wei, Another look

Lao Tzu’s Wu Wei, or no action is his principle teaching. This can be understood as Without Action. There are two aspects of everything, link the Yin and Yang, there is With and Without. The key difference between Christ and Lao Tzu is that Christ is masculine while Lao Tzu is feminine. Remember Lao Tzu saying about the mysterious female? Tao is feminine in nature. Christ says, Love your neighbour like yourself, Lao Tzu says treat everyone as grass dogs. Christ is the active, the With, Lao Tzu is the passive, the Without. Christ loves with passion, Lao Tzu is indifferent and he had peace in his heart.
One of the principles of all Eastern religion or philosophy is non-violence, not harming. Christianity says Love. There is a fundamental difference here.
Lao Tzu says only when beauty is agreed upon, ugliness arises. Now how do you love without hate in a traditional sense? If you don’t want to hate, you must also don’t love. Here is the catch, you can’t just have the “good”, If you want the “good”, you will have the “bad”. You want one end, you must also have the opposite. That is what Lao Tzu says the Saint will embrace oneness, not duality. To do that, the means is Wu Wei.
Wu Wei is also the key to true relaxations. Relaxation is about Withouts. Without tension in the body, without thoughts in your mind. True relaxation will give you strength.

Whose side are you on?

When you watch World Cup Football, do you have a personal favourite? When Federer and Nadal play, who do you want to win? When Israel and Palestinians kill each other, who do you think is evil?
How many judgements do you make in 5 minutes?
Two ladies chats on the train opposite to you. They talk about Brad Pitt and other celebrities you vaguely know. What is going on in your head? How did you judge them?
Come on, let’s not kid ourselves.
We make judgement in a subconscious level. We think we are righteous, we hate evil. Those who are different to us are evils.

Think again.
Is it possible you support Israel simply because you were born as a Jew? If you happened to be born in Palestine, you might be one of the suicide bombers. I don’t want Taiwan to be independent just because I was born in the mainland. Which side do you take seems just a random chance.
Lao Tzu says, The saint is not kind, he treats every one just as the sky is treating the earth. The sky does not care about what we want; it will rain when we planned a BBQ. We, in order to find peace, should be just like the sky. This is Dispassion. The word indifference is a great word. It means don’t care. Why? Because there is no difference. Do not take sides. Get out the predefined circle of you limited birth. Be indifferent. Because there is no difference. Only then is it possible to find peace within.

Surrender

I might have been pretty slack recently. I was not reading any masterpieces and I was reading quite a few blogs. An Ashtanga blogger who use to be an aerobics teacher wrote that she finally surrenders her practice. The question is why we choose not to surrender in the first place. The opposite word is struggle. We often hear people talking about the struggles of life. Is it originated from the fact we are not surrendering? I can understand that there are certain things to be desired, such as being able to fully master the primary series. This is years of hard work. But what happens next? The intermediate series is a whole new aim. We are still not good enough. Or are we?
Oshu kept telling us we are already good enough. My understanding is that we are not really good enough; otherwise there is no need for us to do anything. What is important is that the fact that we are not good enough is not important. My biggest desire today is to be able to practice with utmost concentration. However, my mind wanders during the practice. I use to blame myself when that happens. This is struggle. This is not surrender. My teacher said to me once that when that happens, just think about the duck in the water. The duck is in the water and yet it is not wet the moment it is on land. It shrugs off the water. The water simply cannot stay. So are our thoughts. It is not important when our mind wanders, when it happens, we just gently draw it back. If the duck complains about the water on its skin, it would not have been doing anything else. Whatever your imperfection is, it is not important. I guess that is why Guruji just say one thing: Practice and all is coming. It really includes all.

On Goals

蔺且问道：“何谓用志不分、乃凝于神？”
庄周回答说：“当一个人的注意力完全集中于某一个事物时，他的精神就会与物合
而为一，佝偻丈人粘蝉的手艺说明，人要想做好任何事情，都必须摆脱名利的束缚，将
全部身心投入进去。养生亦是如此。”

This is an excerpt of the Biography of Chuang Tzu, by Wang Xinmin. I had been reading this book for the last few days.
We had always had goals. In schools we are taught so, in families, the parents set the goal for us. The Tao, however, is goalless. The Tao is in everything, be it spiritual or material. A trader friend told me he forgot how much he is going to make or lose when he was actively trading the stock market. Had he worried about the outcome of the trade, he would have lost. Here he had a taste of Tao in trading. In Yoga practice, the same Tao applies. If the goal is to be able to practice the first Asthtanga Primary Series, the essence of yoga is lost in the goal. If the goal is not to have a goal, then Tao itself is lost. Whatever we do, share concentration is the most important thing, and in fact the only thing that matters. It is only then, perfection is achieved.
Non-attachment is all reaching, in every aspect of life. The obvious ones are fame and wealth, but it also applies to sainthood and spiritual advancement. When true non-attachment is with one person, he non-attachment itself is not discipline for him. A monk meditates all his life in attempt to know the Tao is sadly no different to someone who attempt to achieve fame or wealth all his life.

End of translation

The chapters from here till the end of the Tao Teh Ching is focused on the running of a country. This is important on its own right, but I find myself less attracted to this subject. The governing of a country is called politics and although there is some truth involved, it is generally other people’s job. For my own interested in the study of the Self, I decide to stop translating the remaining chapters. Therefore this blog stops here. I will write others thoughts when they come to me.

Chapter 55

含德之厚，比于赤子。毒虫不螫，猛兽不据，攫鸟不搏。
骨弱筋柔而握固。未知牝牡之合而全作，精之至也。终日号而不嗄，和之至也。知和曰常，知常曰明。
益生曰祥。心使气曰强。物壮则老，谓之不道，不道早已。

Translation
When one possesses the abundant Teh, he can be described as a new born baby. The venomous insects will not bite him, the wild animals will not attack him, the birds of prey will not strike him.
His bones are soft, his sinews pliable and yet his grip is firm. He does not know the union between the male and female, and yet he fully experiences, this is because his ultimate cultivation of the essence (semen). Being an infant, he cries all day long and yet never get hoarse, this is because his ultimate cultivation of harmony. To know the harmony one is remains undisturbed, and in turn become enlightened.
To cultivate life is a good omen. One gains strength when direct the breath from the heart. When things become strong they grow old, which is opposite to the Tao and its death is loomed.

Note
Recently I have been reading Yogananda’s book, Autobiography of a Yogi, which is so good that I didn’t find time to visit Lao Tzu. However it is interesting that in the book, Yogananda described an experience of his master, when the insects of northern India never bite him.
There are a couple of interesting points. First the firm grip comes from the seemingly weak bones and pliable sinews. It is perhaps true that the weight lifters do not live a long life, so called物壮则老. The internal organs and sinews are week and rigid, his life force has departed him. There is vague indication in this chapter on how to achieve this, that is 心使气, to direct the breath from the heart. No special techniques, is mentioned, how to use the heart to direct the breath? Perhaps Lao Tzu knows that this cannot be written in text and can only be learned from the masters.
Second is the mentioning of the 精, which literally means semen. It is believed in China, without western scientific proof, that the semen is the essence of blood. In Indian systems, the semen is even more precious. In the text Lao Tzu describes the Sage as not knowing the union of the sexes. Does this mean he believed the householder cannot be a sage?