From Alex’s TLP post: http://thelastpickle.com/blog/2016/12/08/TWCS-part1.html
TWCS is no fit for workload that perform deletes on non TTLed data. Consider
that SSTables from different time windows will never be compacted together, so
data inserted on day 1 and deleted on day 2 will have the tombstone and the
shadowed cells living in different time windows. Unless a major compaction is
performed (which shouldn’t), and while the deletion will seem effective when
running queries, space will never be reclaimed on disk.
Deletes can be performed on TTLed data if needed, but the partition will then
exist in different time windows, which will postpone actual deletion from disk
until both time windows fully expire.
> On May 5, 2017, at 1:54 PM, John Sanda <john.sa...@gmail.com> wrote:
> How problematic is it to perform deletes when using TWCS? I am currently
> using TWCS and have some new use cases for performing deletes. So far I have
> avoided performing deletes, but I am wondering what issues I might run into.
> - John