Unlike other strategies, dtcs has tombstone compaction disabled by
default due to:
- deletion shouldn't be used with DTCS; rather data is deleted through TTL.
- with time series workloads, it's usually better to wait for whole sstable
to be expired rather than compacting a single sstable when it's more than
20% (default value) expired.
See CASSANDRA-9234 for more details.
For tombstone compaction, unworthy sstables are filtered out and the oldest
one is chosen because it's the one less likely to shadow data and it's also
relatively big.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
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