@kyanny's blog

My thoughts, my life. Views/opinions are my own.

MongoDB Tokyo 2013

I attended MongoDB Tokyo 2013. I heard three sessions at noon.

(Since I forgot to get any novelties so there are no photos in this post :(

Indexing & Query Optimization

David talked about indexing and query optimization on mongodb. He tried to explain not only what index is, but how it works by diving into B-Tree index explanation. It was quite good to understand why some queries can't get benefit of poor-designed indexes. I have an experience of MySQL so I often noticed these are very similar on indexing. Since his presentation material has a lot of sample codes, I really want to see it again on the web.

Data Processing and Aggregation Options

Stephen introduced about useful tools for data processing on mongo. He explained Aggregation Framework at first. It sounds very powerful. Moreover it looks not so complex. He talked about MapReduce and integration to external services like Hadoop too. In conclusion he suggested Aggregation Framework as might be a best solution. I'm not sure whether I really want to do heavy server-side data processing, but if the time is coming I will try Aggregation Framework at first.

Data Modelling Examples from the Real World

In Matias's talk, he explained the difference of thinking about schema design between RDBMS and mongo. He also showed us two "real world" examples to solve common problem of application development. Actually this session is main purpose why I went to that event. He explained "message inbox" and "history" data model patterns. I think it was a presentation about designing application architecture. That's very good. He concluded that the important point is to make sure the use case of your application. There are many solutions and cases.


There were many business person wearing suit. Usually I'm scared of "suit" guy, but I also impressed that those business person really interests about MongoDB. I guess MongoDB is definitely used in serious business world and many people pay proper money to MongoDB business. It's quite good. I hope the MongoDB company (formerly 10gen) to keep growing in future.

All of English sessions had one-by-one translation. Translation itself was good, but truth be told I was not satisfied with quality of translation. It can't be helped though, translators didn't seem to have enough technical knowledge, so they sometimes said strange translation. For example, when speaker explained about querying with regular expression, he said the pattern starts with caret character (/^foo/) will use index. But translator called this symbol "carrot" (speaker jokingly performed to bite carrot, lol) In that case, we might not need translation about "caret" because it was very clear for most of audiences (I assumed attendees were engineers..)

But I want to say thank you to translators again, because due to one-by-one translation, speaker talked slowly and intermittently so I could hear and concentrate their speech relaxed. I think it was good for not only people who can't listen English at all but also people who can listen English somehow.

I got back to office without attending networking party, but when MongoDB Tokyo 2014 is held I want to attend after party to meet some MongoDB guys too. Thank you all of speakers, organisers, translators and MongoDB staffs.