Arrow is basically a dataframe format. It's not really suitable for building data-structures. Eg one of the things Blobs is being used to implement is a Bε-tree (http://supertech.csail.mit.edu/papers/BenderFaJa15.pdf).
Blobs is less a data-format and more a replacement for C's ability to cast arbitrary memory locations to structs.
* https://github.com/ExpandingMan/Arrow.jl
* https://arrow.apache.org/blog/2017/08/08/plasma-in-memory-ob...