This commit adds information on how to enable
object storage for a keyspace.
The "Keyspace storage options" section already
existed in the doc, but it was not valid as
the support was only added in version 5.4
The scope of this commit:
- Update the "Keyspace storage options" section.
- Add the information about object storage support
to the Data Definition> CREATE KEYSPACE section
* Marked as "Experimental".
* Excluded from the Enterprise docs with the
.. only:: opensource directive.
This commit must be backported to branch-5.4,
as support for object storage was added
in version 5.4.
Closesscylladb/scylladb#16081
(cherry picked from commit bfe19c0ed2)