Towards the end of the semester

Busy with the final projects. The takeaway from this semester is never picking two 395T courses at the same time. Sorry.

— Update: 01/03/18 —

Last semester ends up amazingly well. Every time I read this post, I always picture Prof. Dana Ballard’s pull-up gesture in my mind and how he compares the difficulty of coursework with the workout in a gym: you always want to lift a heavier weight to gain muscles. For an unknown reason, his voice and pull-up gesture always amuse me.


Leaving IBM

To be honest, this is probably the most difficult post I have ever written. This is majorly because there is a ton of stuff I want to say but I’m unsure whether I should keep them public or should keep it to myself. Another factor that makes this post hard to write is because the span of drafting. I have been drafting this post since April in 2016, right after when I decide to start the whole process of quit-IBM-and-get-a-PhD project.  I used to use this post as a log to record things and feelings when somethings happens around me at IBM. Frankly, if I take a look at the stuff I record (mostly are rantings) retrospectively, lots of stuff still hold but the anger just passes away with the time. So, that year-long drafting really makes me hesitate even more because the mood when those stuff are written are gone. However, two years can be a significant amount of time and quitting IBM can be called “an end of era” and I should give a closure to my happy-and-bitter experience with IBM anyway. So, here it goes.


Thank you, IBM!

I’m really thankful for the opportunities working with IBM. This experience really makes me grow both technically and mentally.  Technical-wise, I have the opportunity to get hands on experience with DB2 development. DB2 as a database engine is extremely complex. It has over 10 million lines of code and it is way beyond the scope of any school project. Working on those projects are quite challenging because there is no way you can get clear understanding of every part of the project. I still remember when I attend the new hire education on DB2, there is one guy says: “I have been working on the DB2 optimizer for over 10 years but I cannot claim with certainty that I know every bit of the component I own.” This fact really shocks me and based upon my experience so far, his claim still holds but with one subtle assumption, which I’ll talk about later. There are lots of tools are developed internally and reading through both the code and tool chains are a great fortune for any self-motivated developers. I pick a lots of skills alongside: C, C++, Makefile, Emacs, Perl, Shell, AIX and many more. I’m really appreciated with this opportunity and I feel my knowledge with database and operating system grow a lot since my graduation from college.

Mentally, there are also lots of gains. Being a fresh grad is no easy. Lots of people get burned out because they are just like people who try to learn swim and are put inside water: either swim or drown. I’m lucky that my first job is with IBM because the atmosphere is just so relax: people expect you to learn on your own but they are also friendly enough (majority of them) to give you a hand when you need help. I still remember my first ticket with a customer is on a severity one issue, which should be updated your progress with the problem daily. There is a lot of pressure on me because I really have no clue with the product at the very beginning. I’m thankful for those who help me at that time and many difficult moments afterwards. That makes me realize how important is to be nice and stay active with the people around you.  Because no matter how good you are with technology and the product, there are always stuff you don’t know. Staying active with people around you may help you go through the difficult moment like this by giving you a thread that you can start at least pull. In addition, participating with toastmasters club really improve my communication and leadership skills and more importantly, I make tons of friends inside the club. Without working at IBM, I probably won’t even know the existence of the toastmasters club. If you happen to follow my posts, you’ll see lots of going on around me when I work at IBM. Every experience you go through offer you a great opportunity to learn and improve yourself. Some people may look at them as setbacks but for me, I look at them as opportunities.


( the picture on the left is all the comments people give to me about my speech and on the right is the awards I have earned inside the club in these two years)

With the help of all those experience, I have developed a good habit of writing blogs (both technical and non-technical), reading books, and keep working out six days per week. All those things cannot be possible if I work at a place where extra hour work commonly happened. I’m very thankful for IBM for this because staying healthy both physically and mentally are super critical for one’s career. Even though those stuff don’t directly come from IBM, but IBM does provide the environment to nurture this things to happen.


IBM has its own problem. The problem is centered around people. There are many words I want to say but I think I’ll keep them secretly but I want to show my point with a picture:


I don’t know why IBM’s term “resource action” on firing employees and the sentence “IBM recognize that our employee are our most valuable resources.” bother me so much. I probably just hate the word “resource” as a way to directly describe people and how this word get spammed so much around IBM. I know everyone working for a big corporation is just like a cog in a machine. However, what I feel based upon lots of things happened around me is that IBM as its attitudes represented by its first-line managers (because those people I commonly work with) makes this fact very explicitly. It hurts, to be honest. No matter how hard you work and no matter how many prizes you have earned for yourself and your first-line manager, you are nothing more than a cog in a machine, which is not worth for high price to have you around because there are many cogs behind you that are ready to replace you. They are much cheaper, much younger, and more or less can work like you because your duty in the machine is just so precisely specified, which doesn’t really depend on how much experience you have had under your belt. To me, that’s devastating.

This leads to the problem that talented people are reluctant to stay with company. My mentor and the people are so good with DB2 have bid farewell to the team. That’s really sad to me because they are the truly asset to the company and the product. The consequence of this is that crucial knowledge is gone with people. Some quirks existing in the product are only known by some people and once they leave the company, the knowledge is gone with them. That makes mastering of the product even harder. That’s the subtle assumption that the person makes during the new hire education and that’s also part of the problem when working with legacy code. The whole legacy code issue is worth another post but one thing I now strongly believe is that any technical problem has its own root cause in company culture and management style. To me, I’m not a guru now but I cannot see the way to become a guru with my current position, which scares me the most

That’s it for this section and I’ll leave the rest to my journal.

“Research” Interest

This week Friday, I meet with my future roommate in Beijing. During the lunch, we had a conversation about each one’s research interest. My roommate, likes me, is also a CS graduate student at Austin. However, unlike me, he has a clear vision about what direction he is going to pursue in graduate school. He just finished his undergraduate degree in Automation department at Tsinghua University. Automation department, as he explained, is similar to a mixture of mechanical engineering and electrical engineering. He has interest in mathematics since high school and naturally, he wants to work on machine learning theory in graduate school with emphasis on computer vision (CV).

Now comes to my turn. That’s a hard question I have been thinking about for a while. I don’t have clear vision on what I’m going to pursue next. I think maybe I’m too greedy and want to keep everything. However, I also realize that I may not be as greedy as I thought initially. I know I don’t want to work on computer architecture, computation theory, algorithm, compiler, network. Now, my options really just choosing among operating system, database, and machine learning. For the machine learning, I even know I probably won’t choose computer vision eventually (still want to try a course though) and I more lean towards the natural language processing (NLP). However, picking one out of those areas is just too hard for me now, even after I did some analysis in my last post trying to buy myself into picking machine learning only. There is always a question running in my head: why I have to pick one? Sometimes I just envy the person like my future roommate who doesn’t have this torture in his mind (maybe he does? I don’t know).

This feeling, to be honest, doesn’t new to me. When I was undergraduate facing the pressure of getting a job, a naive approach is just locking oneself in the room and keeping thinking what profession might suit me the best. After two years of working, I grow up enough to know that this methodology on making choice is stupid and I also grow up enough to know that “give up is a practice of art”. Why I’m in this rush to pick the direction I want to pursue even before I’m taking any graduate course yet? Why can’t I sit down and try out several courses first? Because I want to get a PhD in good school so bad. Let’s face the fact that people get smarter and smarter in generations. Here “smarter and smarter” doesn’t necessarily mean that people won’t repeat the mistake that happened before. It means that people will have better capability to improve themselves. Machine learning is not hot in 2014 from my experience in college. Back that time, Leetcode only has around 100 problems. I have no particular emotional attachment to machine learning material when I’m taking the AI class. Maybe because wisconsin has tradition in system area? I don’t know. However, in 2017, everyone, even my mother who is a retired accountant, can say some words about AI, machine learning. Isn’t that crazy?

On my homepage,  I write the following words:

I like to spend time on both system and machine learning: system programming is deeply rooted in my heart that cannot easily get rid of; machine learning is like the magic trick that the audience always want to know how it works. I come back to the academia in the hope of finding the spark between these two fascinating fields.

Trust me, I really mean it. Maybe because I graduate from wisconsin, I have naturally passion for system-level programming, no matter it from operating system or database. Professor Remzi’s system class is just a blast for anyone who wants to know what’s going on really under the software application layer. Professor Naughton’s db course is fully of insights that I can keep referring to even I begin to work a DBMS in real world. Wisconsin is just too good in system field and this is something that I can hardly say no even I have work so hard lie to my face saying that “system is not worth your time”. What about machine learning? To be honest, great AI dream may never accomplish. Undergraduate AI course surveys almost every corner of AI development but only machine learning becomes the hottest nowadays. Almost every AI-related development nowadays (i.e. NLP,  Robotics, CV) relies on machine learning technique support. Why I’m attracted to machine learning? Because it’s so cool. I’m like a kid who is eager to know what is going on behind magic trick. Machine learning is a technique to solve un-programmable task. We cannot come up with a procedure to teach machine read text, identify image object, and so on. We can solve these tasks only because the advancement of machine learning. Isn’t this great? Why both? I think machine learning and system becomes more and more inseparable. Without good knowledge about system, one can hardly build a good machine learning system. Implementing batch gradient descent using map-reduce is a good example in this case.

I just realized that I haven’t answered the question about rushing towards the making decision. In order to get a good graduate school to pursue PhD, you need to demonstrate that you can do research. This is done by publishing papers. Most of undergraduates nowadays have papers under their belt. That’s huge pressure to me. Master program only has two years. I cannot afford the time to look around. I need to get started with research immediately in order to have a good standing when I apply to PhD in 2018.

So, as you can tell, I have problem. So, as a future researcher, I need to solve the problem. Here is what I’m planning to do:

  • Take courses in machine learning in first semester and begin to work on research project as soon as I can. I’ll give NLP problem a chance.
  • Meanwhile, sitting in OS class and begin to read papers produced by the Berkeley Database group. People their seem to have interest in the intersection between machine learning and system. This paper looks like promising one.
  • Talk to more people in the area and seek some advice from others.
  • Start reading “How to stop worrying and start living

Will this solve the problem eventually? I don’t know. Only time can tell.

What are some useful, but little-known, features of the tools used in professional mathematics?

What's new

A few days ago, I was talking with Ed Dunne, who is currently the Executive Editor of Mathematical Reviews (and in particular with its online incarnation at MathSciNet).  At the time, I was mentioning how laborious it was for me to create a BibTeX file for dozens of references by using MathSciNet to locate each reference separately, and to export each one to BibTeX format.  He then informed me that underneath to every MathSciNet reference there was a little link to add the reference to a Clipboard, and then one could export the entire Clipboard at once to whatever format one wished.  In retrospect, this was a functionality of the site that had always been visible, but I had never bothered to explore it, and now I can populate a BibTeX file much more quickly.

This made me realise that perhaps there are many other useful features of…

View original post 695 more words

Some thoughts on learning

刚才在YouTube首页随便打开了一个推荐视频,视频的名字叫做How to Learn Faster with the Feynman Technique (Example Included)。我个人其实很少点开这种带有非常强烈功利色彩的标题去看的,更别提是这种方法论的视频。并不是说我讨厌这类视频,我只是觉得这类视频看多了,如果不立刻去实践的话,看了也没有任何效果,反而浪费掉了很多时间。这个视频本身不长5分钟左右,看完后,我不仅觉得这个方法可以试一试,而且更重要的是让我回忆起过去看过的一些东西以及一些想法。所以赶紧记录在这里。


这个方法的核心就是explaining the concept。一个典型场景就是去office hour找老师问问题:在你向老师解释完问题,你的疑惑点,以及你的解决方法之后,很有可能出现的情况就是还没等老师说话,你就说:“噢,我懂了。谢谢老师!” 然后转身跑出了办公室。这个场景体现出两个要点:1. explaining the concept确实非常重要 2. 也许这个问题已经在我们的内心里过了无数遍,却只有我们向另一个人解释的时候我们才会 “噢!!!!”。 第一点不难理解。但是第二点确是极度困难:我们从哪里能找到一个愿意天天听我们explain what we have learned的人呢? 上面的视频提出了一种解决办法,步骤如下:

  1. 找张纸,把你要解释的概念写在纸的最上头
  2. 假装有一个第三方在场,用你自己的语言向他解释这个概念。这里作者有几点强调:
    1.  用最通俗易懂的语言来解释
    2. 不要仅限于定义。挑战自己,用例子,图等形式来确定你可以把所解释的概念实际运用起来。
    3. 把在场的这个第三方想像成一个小孩子。这么做的好处就是小孩子会经常问“为什么?” 这个会让我们做到对这个概念的细节有百分百的理解。
  3. 在做完前两步之后,你就要重新回顾你在哪些地方解释出现模糊,拿不准,或者不知道。这些地方就是我们对这个概念理解薄弱的地方。我们要做的就是拿出资料将这些模糊点搞清楚。这步和考完试改错题非常相似。
  4. 这步其实是第三步的引申。就是看之前哪些解释的地方运用了复杂的语言或者堆砌了大量技术概念。我们要做的就是尽力把这些地方用更简洁的语句进行重写。

视频介绍的这个方法其实在各种我所看过的资料里都有体现过。比如在The Pragmatic Programmer一书中讲如何debug一节时,作者介绍的一个技巧叫做”Rubber Ducking”:

A very simple but particularly useful technique for finding the cause of a problem is simply to explain it to someone else. The other person should look over your shoulder at the screen, and nod his or her head constantly (like a rubber duck bobbing up and down in a bathtub). They do not need to say a word; the simple act of explaining, step by step, what the code is supposed to do often causes the problem to leap off the screen and announce itself.

It sounds simple, but in explaining the problem to another person you must explicitly state things that you may take for granted when going through the code yourself. By having to verbalize some of these assumptions, you may suddenly gain new insight into the problem.

这个”Rubber ducking”的来源就是其中一位作者在早期的时候看见一个很厉害的developer经常拿着一个”a small yellow rubber duck, which he’d place on his terminal while coding”。

The Lady Tasting Tea一书的前言中作者也提到作者在写着本书的时候收到了来自他的妻子很多的帮助。因为他的妻子不是statistician,所以如果作者用很technical的语言来写的话,他的妻子根本就看不懂。所以这迫使作者不得不采用更加通俗易懂的语言来解释统计背后的哲学及观念发展。

这也让我想到我最开始写Tech blog的一个主要motivation就是把我所学的东西通过文章的形式解释出来,争取消灭掉不懂装懂的情况。而视频方法的3,4步就是未来我在写tech blog的时候需要更加注意的地方:不要把所学的内容进行简单的归乃重复,要注意用更加简略的语言讲述出来。这里题外话一句:我发现将知识点内嵌在文章里是一个非常不错的保存知识点的方式。这么做我感觉会使知识点不会过于碎片化,并且提供充足的上下文将独立的知识点很有效的串联起来。这也许是“connect the dots”的一种体现吧。


“The first principle is that you must not fool yourself — and you are the easiest person to fool.” — Richard Feynman

Thoughts on PhD


This post serves as a record of thoughts regarding PhD. This post is from the person who is about to embark on the journey of getting a PhD. The thoughts from this post may look stupid or naive for someone who has already gone through the phase. However, based upon my past experience, if you don’t have some baseline for something that you decide to begin fighting for, you can barely have a measure on how much you have progressed when you actually start to fight, and highly likely, you may fall into the same trap over and over again for future similar situations.

Let’s dive into …

I have been considering getting a PhD since my sophomore year at University. This page summarizes some commonly-seen motivation for people getting a PhD. I think mine can be partly described as “Dr. Hu — sounds cool!” and “Eternal quest for knowledge (yeah right!)”. Another part, I guess, probably be the childhood dream of becoming a scientist. However, now, after two years working in industry, I realize that the most important motivation for me to get a PhD is that I want to have the ability to solve the problem that nobody explores before. This is different from quick learner because quick learner means grasping the material that has already studied before quickly. But, that doesn’t mean he can handle the unexplored area very well. I like to ask “why” when I face a problem but gradually I realize that I don’t have enough knowledge and more importantly, the confidence to solve some of crazy ideas in my mind. So, getting a PhD means I build some good knowledge foundation in some specific area and process the ability to solve any open question, even it is from the area that I haven’t explored before.

However, getting a PhD is a non-trivial task and itself demands lots of commitment. I personally view PhD and marriage are two the most serious commitment a person can ever give in his entire life. I try to play “rational” card here by doing some evaluation beforehand because I’m type of do-something-that-can-be-successful person and several years of study in economics make me become more and more like a “risk-averse” kind of person. So, I do various RA jobs in various departments (i.e. Math, Psychology, Biostatistics) to get a sense of what PhD life might look like.  The result is not good for me because I find out that working on some topics that you have the least interest in can be a lot like being in jail. However, those undergraduate research experience also has its positive side.  Imagine if I jump into the graduate school directly and choose some direction that I have no interest in (i.e. medical imaging),  I am sure that I cannot survive till the end. Sometimes I feel that the process of making decision is a two-way street: one way to do is to pick something that fits you from the pool; the other way is that you get rid of the choices that definitely do not work for you and then see what is left inside the pool. Apparently, for me, the latter strategy works slightly better.

So, I choose to work in industry for two years to find the things that I have passion about.
There isn’t much left in my choice pool by that time: I either pick from AI or from system.  For AI,  my focus is majorly on the application of ML techniques, such as CV, NLP. For system, my choice is distributed system (i.e. distributed database, distributed file system).  So, I need to carefully think about the pro and cons for which track I decide to pursue. Like I said in my offer choice post, there can hardly be a perfect choice that meets your need by any measure. Preference ranking in economics may be too ideal.  There is always trade-off. After spending two years working in database, I realize that I’m not really a hardcore system guy.  The most attractive feature from system is that I can do lots of coding. The coding here is naturally different from coding in, say, ML. In system, most of coding is done involves implementing data structures, data process models, and so on. However, for ML, coding is more like a direct translation of some mathematical formulas. However, the problem I find out about system research is that it is hard to propose problems that can directly link to the industry level production. This problem becomes clear to me after I attend DTCC 2017 last week.  The key success element for building a system is the production painpoints or user scenario. Alibaba and Tencent build system just to cater their specific business scenarios. In my view, the system has value once it can solve some specific problems that are not formed from someone’s imaginary. This can be very hard for newcomers who just join inside academic circle. In this case, advisor may work like a offer manager who regular visits companies to see what kind of problems they try to solve and bring those practical problems back to the research group and hopefully these issues can be resolved by his students. Research is all about solving problems and great research comes from the problems that have or potentially have great impact in the industry or people’s daily life.

In addition, if I recall the fun course experience from my undergraduate, I realize that I have much more fun with manipulating formulas and work out the problem that has strong connection with people’s daily life. The biggest trend right now is on big data. However, to be honest, for database system developer like me, I can barely get in touch with actual big data in my daily work. So, whether the system I build is robust enough to handle the actual big data, I don’t know. The only thing I can say is that I implement the design correctly. So, I feel like it is really hard to work out some good system by spending most of the time in school. This idea is partially confirmed by the trend that people jump out of academia and head to the industry like this.  However, even I have spent almost all the space so far talking about the “problems” I have observed about system research. I do enjoy the “traditional” programming scheme that system research possess. Rather than taking some data and train a somewhat blackbox network to achieve outcome, traditional if-else programming feels more rewarding for a hardcore programmer.

For AI, things can be radically different from system. Specifically for ML, one thing I learned is that ML is used to solve for the task that can hardly solvable by traditional programming, like autonomous driving, pattern recognition. Those stuff has strong connection to people’s daily life, which means can make a lot more impact. This is some historical pattern that can be easily observed: serving individual people is lot more profitable than serving big companies. Doing research on system is a lot like serving big companies if we consider the problem: who needs to build infrastructure from scratch? However, working on AI is a lot like serving people by making iPhones. If we observe the trend of companies like IBM and Apple, this analogy can easily work. So, even programming in ML is less satisfying in my sense, we just need to embrace the future to better maximize our utility.  Of course, mathematics are quite bit involved in the field of AI, and tweaking parameters of learning models can feel quite subjective. However, I guess that’s some obstacles I need to face. The rationale is same as before: there is no perfect choice and we just need to try even if we have only 10% confidence about success.

Last word …

The motivation for considering this issue right now is that I need to start planning my course schedule for the upcoming semester. The course schedule can be balanced between system and AI. But, it can also be AI focused. So, I really need to evaluate myself to see which direction I want to go.  There is a famous quote in China: “Choice matters!”

Takeaway from DTCC 2017

由于同事出差,我有幸参加了在北京国际会议中心举办的第八届中国数据库技术大会(Database Technology Conference China 2017)。这是我第一次参加业界交流大会,内心还是格外兴奋的。这次大会确实有很多的收获,我想用这篇博客记录下来。本来我想用英文记录的,毕竟对于计算机领域,英文是我的“母语”,但是介于分享主要以中文为主,所以我就还是以中文来记录了。



Get some sense from the peers

Focus on your own product is quite important. However, it’s even more important to see how your peers doing. I’m not an architect yet but I feel it’s helpful to begin thinking like an architect and see what the problems that your peers are facing and how they try to solve them. In addition, by knowing how’s the going with your peers, you may get a measure of yourself: is the work you are doing on the same level as your peers? Are you in a good shape in the job market? What’s the gap you need to fulfill skill-wise?

Deepen the understanding of the field

Even almost two years working on the database field, I still think myself as a newbie. This is mainly because database is arguably the most complex software that people can ever make and there are tons of stuff I don’t know. So, I want to see in a high level that what’s the trend of the field and what kind of reflection that people derive from their day-to-day engineering practice. I think this may help me to catch-up with the masters.

AI or System?

As I disclosed in my last post, I decide to head back to school and get a master degree. To be honest, my ultimate goal is to acquire a PhD in Computer Science and currently I’m actively preparing for it. The most important question is that which field I want to study?  I have two options and I have some interests in both fields: AI and System. Why these two options and not others is worth a whole new post and I don’t want to discuss here. So, my task for now is to gather as much information as possible about these two fields and see which one looks more attractive to me. This event is extremely helpful because it has sharing on System as well as on AI.

Day 1


年度主题解读 (曹鹏 – 京东金融副总裁)


  1. Finance领域受到了机器学习的冲击,最近几年有越来越多的FinTech公司出现。机器学习在这种公司的主要应用从这个分享来看是对客户群体更加精确的定位和分析。相应的,对于量化交易策略的作用,这个分享没有涉及。我最近一直比较关心机器学习在金融领域的应用,但是从这个分享上,我没有找到我想要找到的答案。因为,在我看来,对客户群体的精确定位是一种机器学习的通用应用,并不具备金融行业的独特性。
  2. 数据公司在我看来是一个不错的创业想法。分享中提到数据对于京东金融的重要性。他们不仅要求数据的广度,也要求数据的厚度。一个重要问题是数据是具有很强的时效性和冷热变化的。一年前顾客的消费记录对于现在来说并不具备非常强的指导意义。因此,京东金融每天都要收集大量的数据(~6TB)来保证整个分析的准确性。同时,演讲者透露出即便在这种情况下,他们觉得数据还是远远无法满足他们的需求的。这个就能解释为什么IBM最近收购了The Weather Company和医疗影像公司Merge Healthcare:无非就是看上了这两家公司的数据。这让我想做数据贩卖商会不会是一个不错的创业点子呢?

数据库发展概览 (吴承杨 – 甲骨文)


  1.  在去IOE喊了那么多年的今天,Oracle的市场占有率依然有56%之多
  2. 数据库的未来是云:这里演讲者用一个case讲述hybrid cloud的重要性。企业现在面临的问题是如何将公有云的数据和本地服务器上的数据有效的对接在一起以及如何将公有云私有化等。整场演讲更像是Oracle解决方案介绍会,技术方面很少涉及,但是指出了未来数据库发展的方向:上云。
  3. 演讲者台风不错,是一个不错的演讲者。

数据技术的下一站 – 数据应用 (王桐 – 永洪科技)



达梦如何冲击核心业务系统 – 国产数据库的产品发展之路 (韩朱忠 – 达梦数据)

我觉得这个分享可能是今天最励志的分享了。整个分享讲的就是一个国产小厂商是如何奋斗和外资数据库斗争,一点点争取市场份额,成长到今天这个样子的。这里边讲到的一个关于他们对这个用C写的数据库的SQL优化能力进行提升的例子。 他们曾经遇到过一条SQL, 长达3.9K行,换句话说就是粘到word文档里能粘350多页。里边包含着17个inner join, 557个子查询, 831个or筛选, 1000+个查询字段,2731个case when。他们通过不断优化将这个SQL语句从几百分钟降到不到1秒。另外一个故事是讲国产数据库生存的艰辛。因为大企业及银行电信等核心产业的数据库都是采用外资的, 国产根本进不去。国产只能在中小企业市场去竞争。但是,这家数据库通过自身的不断努力,终于拿下国家电网的单子以及西藏和东方航空的单子。这在我看来是非常了不起的成就。这就让我对IBM产生了反思。我不觉得我们DB2能在不经过针对性的优化的情况下就能处理这么复杂的SQL语句。这个例子也让我觉得要么我们是在用我们的名声和过去的积累在赢得客户,要么就是DB2售前的同事在做POC的时候super tryhard。我明显感受到我们和这些国产数据库在努力程度上的差距。也许有一天我和他们的地位会呼唤?我相信这是IBM高层不愿意看到的事情。我们确实该努力了。

SSD的IO Determination特性在数据库业务优化中的应用与拓展 (阳学仕 – 宝存科技)

这个是从storage上出发来讲如何用软件模拟硬件来提升读写速度。换句话说,这个分享带给我的思考就是数据库怎样才能利用IO determination提升读写速度。这里讲的IO determination我粗浅理解看来就是让硬盘上的应用能更加和谐共处,并通过提升应用优先级,IO资源上下限,以及时间上对读写顺序进行优化等方式来使应用获得所需要的资源。另外SSD对于网络发展的匹配也有涉及:通过硬件的提升,我们现在基本可以做到本地写入和通过网络写入远程只有10几微秒的差距。这些在我看来是属于OS的领域。硬件对DB的加成这个方向让我感到耳目一新。

面向未来的数据库体系架构的思考 (张瑞 – 阿里巴巴)


  1. 国内厂商和IBM在对待数据库上有本质上的区别。国内厂商如阿里巴巴,腾讯,以及百度都是以自身业务痛点作为出发点对自家的数据库进行开发和改造。所以相应的,这些家的数据库改造,提升都是带有极强的针对性的。他们的数据库架构可能并不具备非常强的通用性。相反,IBM是把数据库作为产品来销售的,因此在数据库本身设计上考虑到的更多是面面俱到,大而全的尽可能满足所有用户类型的需求。这就导致在某些场景下,IBM的DB2做不到像AliSQL, OceanDB, TDB那样强劲。因此,在超大型公司做数据库,最终方向可能都是“私人订制”。
  2. 机器学习与系统结合的越来越紧密。这里演讲者提到他们想在未来把自动运维转换到智能运维上面来。SQL不再是DBA来手动看,而是通过ML的某种方式来进行优化。这些阿里的人还没有想好但是他们觉得这是未来的方向。


下午听的有”百度NewSQL数据库系统”, “Tencent MySQL内核优化解析”, “滴滴大数据应用”,“自然语言技术在文智趋势分析产品上的应用”。百度上最大收获是说现在分布式事物数据库非常的热,如果研究透,就没有在国内趟不过去的问题。另外一点收获就是不要过分崇拜Google系统。虽然细节我没有听的特别懂,但是从演讲者言语间我感受到,黑猫白猫抓到耗子就是好猫。有的时候不能太学究。而且系统之间即使是理念一模一样,但是由于implementation不同,也会导致巨大的性能差异。

腾讯的讲的非常Technical, 加上演讲者是技术出身,整个session非常的煎熬,感觉就是内核优化是个大坑,需要很扎实的DB知识。最后两场我选得是和机器学习相关的。不得不说没有达到我心中的理想。滴滴介绍的是他们一些数学模型应用的场景。我感觉演讲者应该是加入滴滴时间不长,并没有从一些模型上讲出个所以然来,反倒是应用场景上更让我感受到经济学家也是有用武之地的:比如说如何运用高峰涨价来调控司机和打车人之间的供求关系,以及如何收取取消订单等行为给平台所带来的损失。也许是民怨太重,整个滴滴分享感觉像是个新闻发布会。最后的自然语言技术应用是非常无聊的。演讲者是产品经理出身,主要介绍了下腾讯是如何针把NLP技术应用在新闻上的。非常泛泛,没有提及一些NLP上的技术难点,非常失望。

Day 2


  • Informix现在是和物联网IOT紧密的捆绑在了一起

在IBM我的邻居就是Informix Technical Support组。他们组的老大之前也分享过Informix在物联网领域的应用。这在我看来是为Informix这个昔日的巨人在找新的发力点以获得新生。这点也在今天题为“万物互联时代的数据库支撑平台–SinoDB”上获得了印证。SinoDB可以理解为Informix的fork因为这个公司从IBM这里获得了Informix的源代码的授权。不得不说的是IBM在这里变成了吐槽的对象,这些以Informix元老员工成立的公司认为IBM并没有善待Informix这个继子。他们认为是时候把自己的“孩子”重新领回来让他茁壮成长了。这也让我不得不思考当初IBM收购Informix到底是为了什么?问了问和我一同参会的同事,Informix的代码是否已经和DB2的有机的融合在一起现在还是个未知数。这也让我明白为什么在Oracle收购MySQL之后会出现这么多MySQL的fork:毕竟不是亲儿子。

  • 问题的多重性和domain knowledge的重要性

下午场我就是盯着机器学习专场在听。其中我觉得来自连家的“机器学习技术在房屋估价中的应用”的分享最为有意思。分享的内容其实从标题就可以猜出个八九不离十。这个分享一个重要的信息就是机器学习并不是以算法为核心的而是以建立在以domain knowledge为支撑的加工过的data的基础上的。对于链家的问题就是他们的数据量是十万级的,远不及一些图像处理或者文本处理的亿级别的数据。另外他们的数据是类别变量和连续变量混合,连续变量有数量级差异;以及不可避免的脏数据。这些都很大程度上决定了要基于domain knowledge的feature engineering和针对数据特点的算法确定。现在想想也就不难理解为什么从在本科上统计课到现在看的Prof. Andrew Ng’s ML课程,大家拿到数据的第一步都是plotting:就是为了能更好的结合自己的domain knowledge来观察数据特点及预处理。另外说一句就是,在我看来从昨天的滴滴大数据应用到今天这场链家的机器学习应用,他们本质上处理的问题都是属于经济学范畴。与经济学中计量经济所不同的是,机器学习的方法更加暴力:分析数据就是分析数据,而不是先要把问题归类到经济,然后按照经济的科班套路先建模再通过数据验证模型的套路来解决问题。我这里不想说也不够资格说哪个解决问题的方式方法更好。我想说的是一个问题放在不同角度来解决套路真的是完全不一样。站在不同位置上看待同一个问题也许能会擦出更加明亮的火花?

Day 3

最后一天就是全天的专场了。前两天听下来基本上对System, ML方向有了个粗略的sense。到了第三天我就把重点放在了其他一些领域比如说区块链。这里我觉得讲的比较好的就是“区块链与大数据技术结合的商业应用”这场。可以看出的是区块链作为一个新兴技术,由于账本本身是公开的,可以把 这个想象成一个巨大的只支持insert和select的数据库,那么对于这个数据库里的数据挖掘和针对这个数据库所能做的一些优化就成为了现在区块链届关注的重点。据介绍现在这个账本已经有3,400G这么大。我另外了解到,分布式账本这种技术应用场景还是非常广泛的。比如说红十字会接受捐赠就可以利用区块链技术使得所有捐款信息完全透明公开。说句题外话,现在任何一个项目都需要不同类型的人才。系统,AI都有自己施展拳脚的空间。