I introduced Ruby and Apache Arrow integration including the "super fast large data interchange and processing" Apache Arrow feature at RubyKaigi Takeout 2021. This talk introduces how we can use the "super fast large data interchange and processing" Apache Arrow feature in Ruby. Here are some use cases: * Fast data retrieval (fast (({pluck}))) from DB such as MySQL and PostgreSQL for batch processes in a Ruby on Rails application * Fast data interchange with JavaScript for dynamic visualization in a Ruby on Rails application * Fast OLAP with in-process DB such as DuckDB and Apache Arrow DataFusion in a Ruby on Rails application or irb session