This document introduces Hyunsik Choi and provides an overview of his background and experience. It states that he has a PhD in computer science and engineering, is currently the director of research at Gruter Corp in Seoul, and has been a long-time open source contributor to Apache Tajo and Apache Giraph. The document concludes by outlining Choi's planned presentation on Apache Tajo, which will cover the project overview, architecture, distributed processing model, and current status.
375. An Example of Distributed Execution Plan
Join-groupby-sort query plan
Distributed query execution plan
select col1, sum(col2) as total, avg(col3) as average from r1, r2
where r1.col1 = r2.col2 group by col1 order by average;