What's the most popular NoSQL?

I'd say that the answer is a MongoDB.

MongoDB is growing quickly in popularity because it offers a relatively rich range of features, while maintaining impressive speed. The features include built-in Indices, range queries, support for replication, and auto-sharding. A Map/Reduce function allows you to add to the aggregate functions natively supported and do large-scale jobs like nightly reports.


According to some reports, Java-based NoSQL solutions seems are not free from the GC(Garbage Collection) and performance problems. MongoDB is written in C++ but has drivers for Perl, Python, PHP, Java, and Ruby ... So, powerful!

The infinity/infinitesimal does not exist.

life and death, yin and yang, start and end, creation and destruction, ...

The infinity/infinitesimal does not exist.

Software versioning

How do you versioning your software?

This is so embarrassing, I didn't know well about Software Versioning before reading the MongoDB book. Because, I mostly worked for web-service companies which don't develop the software product and care about software versioning. (Other country companies may not, but at least 'korea web-service' companies does.)

Anyway, I recently learned many things while translating the book, 'MongoDB: Definitive Guide'. :D

P.S., The Korean version of 'MongoDB: The Definitive Guide - O'Reilly Media' is coming soon!

무한의 세계

무한 집합의 크기 Cardinality , 즉 원소의 개수를 수학에서는 '농도'라고 말한다. 유한 집합의 크기는 그대로 원소의 개수 이지만, 무한 집합의 경우는 원소의 개수를 낱낱이 셈하는 것은 불가능하기 때문에 '농도'라...