Thanks, I never heard of Graphlab Create. It is a substantial piece of code! It says it's "out of core", which means it's probably more similar to Parquet/ORC than Arrow. But still interesting.

https://github.com/turi-code/SFrame/tree/master/oss_src/sfra...

For comparison, dplyr and arrow:

https://github.com/tidyverse/dplyr/tree/master/src

https://github.com/apache/arrow/tree/master/cpp/src/arrow

C++ does seem to be useful for stuff like this.