Add a node_owner column (locator::host_id) to system.sstables and make it part of the partition key, so the primary key becomesv PRIMARY KEY ((table_id, node_owner), generation).
This is the first step toward moving the sstables registry into system_distributed: once distributed, each node's startup scan must read only the rows it owns, which requires the owning node to be part of the partition key. Partitioning by (table_id, node_owner) turns that scan into a single-partition read of exactly the local node's rows.
Fixes: https://scylladb.atlassian.net/browse/SCYLLADB-1562
No need to backport this, keyspace over object storage is experimental feature
Closesscylladb/scylladb#29659
* github.com:scylladb/scylladb:
db, sstables: add node_owner to sstables registry primary key
db, sstables: rename sstables registry column owner to table_id