Would adding support for JLD2.jl allow Type preservation?

[alex-s-gardner]

I use DataFrames pretty heavily in my workflows, saving and reading to Arrow file. One thing that I find a bit of a pain is that custom types are lost on save. If DataFrames supported reading and writing to JLD2 could the Types be preserved?

[bkamins]

You can currently save and load dataframes using JLD2.jl. Can you please comment what feature are you missing?

[alex-s-gardner]

Apologies, I didn't realize that was already handled. It works fantastic and retains custom type information!

Should JLD2/H5 be added to the list of supported formats?

[bkamins]

If you would think it is useful can you please open a PR?

[quinnj]

Custom type preservation should be fine in Arrow.jl as well; it does require defining the right ArrowTypes overloads, but should work.