When issuing warnings about partitions with the number of rows above a configured threshold, the large partitions handler does not take into consideration the number of range tombstone markers in the total rows count. This fix adds the number of range tombstone markers to the total number of rows and saves this total in system.large_partitions.rows (if it is above the threshold). It also adds a new column range_tombstones to the system.large_partitions table which only contains the number of range tombstone markers for the given partition.
This PR fixes the first part of issue #13968
It does not cover distinguishing between live and dead rows. A subsequent PR will handle that.
Closesscylladb/scylladb#18346
* github.com:scylladb/scylladb:
sstables: add docs changes for system.large_partitions
sstable: large data handler needs to count range tombstones as rows