I prefer the lz4 frame format for the reasons that Antoine stated. To be friendly to users, the Arrow IPC documentation could mention that lz4 compression may break Java interoperability. If block dependency is the only obstacle to Java interoperability, the Arrow IPC implementation could disable this flag as an _implementation detail_. But I think that the _specification_ of lz4 compression in the Arrow IPC format should not carve out exceptions to accommodate current (temporary, I hope) implementation shortfalls in lz4 libraries.
Is https://github.com/lz4/lz4-java the fast Java lz4 library in question? The incompleteness of this implementation is a known problem for other user communities, not only Arrow. It would be a great public service to improve it so that it fully implements the lz4 frame specification. Steve
