Just a heads-up: the week after our 0.9 release, I'll make major changes to our core matrix block library by introducing a new abstraction for sparse matrix blocks (SYSTEMML-377). This will affect all operations of all backends. The benefit is a more memory-efficient representation, which will significantly improve performance over sparse matrices for CP and Spark (less memory bandwidth requirements, less spilling, less garbage collection). However, if you encounter performance degradations or other issues, please file JIRAs or let me know asap in order to minimize the time of instability. Thanks.
Regards, Matthias
