Thank you!
Boris
> On Jul 25, 2017, at 7:44 PM, kurt greaves <k...@instaclustr.com> wrote:
>
> If by "offline" you mean with no reads going to the nodes, then yes that
> would be a potentially safe time to do it, but it's still not advised. You
> should avoid doing any ALTERs on versions of 3 less than 3.0.14 or 3.11 if
> possible.
>
> Adding/dropping a column does not require a re-write of the data and it is
> relatively efficient (it should take seconds, not hours). It's just a schema
> change, so just requires gossip to propagate the schema between the nodes.
> Note that if you drop a column all the data in that column is not actually
> removed from the SSTables until they are compacted. I believe they are
> effectively treated as tombstones if you hit the dropped column (not sure if
> that's how the metrics record them though).
