Miscs

In 2023, I turned thirty. As Confucius said, “At thirty, one establishes oneself.” I’ve managed to accomplish something - started a family, built a career, gained some technical reputation. A year-end review to commemorate 2023.

Recently, a historic debate in the database industry has sparked heated discussion. The post-90s entrepreneur Feng Ruohang, known as the “ace debater” in the database community, has come into public view. Why did he participate in such technical debates that could potentially “start flame wars”? What are his views on the future development of databases? In this exclusive interview, we invite him to discuss his technical journey and hot topics in the database field!

ISD stands for Integrated Surface Dataset, a dataset published by NOAA (National Oceanic and Atmospheric Administration). I recently reorganized this dataset and provided related analysis tools.

Recently gave an interview to OSC Open Source China, discussing the motivation behind quitting my full-time job to start a business with Pigsty: making PostgreSQL easy to use for everyone, and crushing cloud databases!

I saw news about WeChat accessing user photo albums in the background. While such shady behavior from Chinese apps doesn’t surprise me, in the spirit of seeking truth, I got up this morning to investigate whether WeChat is actually doing something malicious.

My solar birthday falling on Mid-Autumn Festival is something that will only happen three times in my lifetime. Theoretically, this should be a memorable day, but the events of this year have left me numb.

Grandfather has passed away. I am beyond grief, but I should still write something in his memory.

A classic problem in cryptography is how to transmit data securely and reliably through insecure channels. Protecting your chats and communications from surveillance and monitoring - easily achievable with just a computer.

In Understanding the Internet, I discussed my views on the internet. Today, let’s talk about the part I deliberately omitted: the setbacks the internet will face.

The future is not necessarily bright, but the path is definitely winding. During this rare leisure time alone in the New Year, I write these random thoughts, writing wherever my mind wanders.

China’s administrative divisions are divided into several levels. The constitution stipulates three levels, but there are actually five levels: the four-tier system of “province—region—county (district)—township,” which becomes five tiers when including the central level.

It was the best of times, it was the worst of times. We were all going direct to Heaven, we were all going direct the other way.

The world trends flow mightily. Those who follow prosper; those who resist perish. This article discusses the essence of the internet, the world under internet rule, the transfer of power, and future impacts.

Through observation and contemplation, we can divide the process of deepening understanding in the mind from accepting knowledge to the highest level of “intuition” into four stages: knowledge, understanding, consciousness, and intuition.

Neural networks are inspired by how the brain works and can be used to solve general learning problems. This article introduces the basic principles and practice of neural networks.

The core of inferential statistics lies in hypothesis testing. The basic logic is based on an important argument from philosophy of science: universal propositions can only be falsified, not proven. The reasoning is simple: individual cases cannot prove a universal proposition, but they can refute it.

Statistical analysis is divided into two fields: descriptive statistics and inferential statistics. Descriptive Statistics is the technology for describing or characterizing existing data and is the most fundamental part of statistics.

Basic knowledge notes on probability theory: axiomatic foundations, probability calculus, counting, conditional probability, random variables and distribution functions

What happens when you divide by 0 in a computer? The answer isn’t fixed - it can differ across different operating systems, programming languages, and even different compilers.

Recently, I needed to design a tag management system for a business. During the process of organizing existing tags, I developed this theoretical framework.

Sorting algorithms are the most fundamental, widely applicable, and frequently tested algorithms in interviews. This article summarizes classic sorting algorithms: selection sort, insertion sort, bubble sort, shell sort, counting sort, quicksort, merge sort, and heap sort - their principles and implementations.

Reading notes on ‘Elements of Information Theory’: What is entropy? Entropy is a measure of the uncertainty of random variables, and also a measure of the information needed to describe random variables on average.

I once thought all day but learned nothing, which is not as good as what I learned in a moment. I came to Hangzhou to attend Alibaba’s Baiji training to learn from seniors and improve my knowledge level!

Unable to sleep in the dead of night, spending the last hour of 2014 reviewing this year and looking ahead to next year seems quite appropriate.

A paper for “History of Secrecy and Secrecy Systems” course, discussing computational thinking and its significance in undergraduate education, as well as methods for cultivating computational thinking among undergraduates.

What a wonderful subject mathematics is

In the final half hour of 2013, reflecting on my experiences this year fills me with deep emotion.

Neural networks emerged inspired by the human brain, so the operational mechanisms of human society also have various similarities and connections with neural network training. Some thoughts on reading Wiener’s “The Human Use of Human Beings - Cybernetics and Society.”

Computer networks are like a logistics system, with the only difference being that logistics systems transmit material entities like mail and packages, while computer networks transmit intangible information.

One inevitably traces back to questions about the world’s origins, and answering these questions is the process of establishing one’s cornerstone principles.

Through observation and reflection, we can divide the mental process of deepening understanding from accepting knowledge to the highest level of ’enlightenment’ into four stages: knowledge, understanding, consciousness, and enlightenment.

Eastern people emphasize macro-to-micro thinking, while Western people emphasize micro-to-macro thinking. In my view, this is the philosophical root of East-West thinking differences and many macro distinctions.

The concept of natural numbers should have been learned in elementary school. The foundation of all elementary mathematics begins with such a definition. However, when I entered university, I encountered this question again in discrete mathematics.

Connecting all concepts in linear algebra through one main thread

Recently, my roommate broke up with his girlfriend. What was once a lovey-dovey, inseparable couple suddenly separated just like that. This inevitably made me start thinking about some questions I hadn’t carefully considered before: What ultimately determines romance and marriage?