I have a table that I'm storing ad impression data in with every row being
an impression. I want to get a count of total rows / impressions. I know
that there is in the ball park of 200-400 million rows in this table and
from my reading "Number of keys" in the output of cfstats should be a
reasonably accurate estimate. However, it is 39434. Am I misunderstanding
something? Every node in my cluster has a complete copy of the keyspace.
Table: impressions_2
SSTable count: 22
Space used (live): 51255709817
Space used (total): 51255709817
Space used by snapshots (total): 49415721741
Off heap memory used (total): 30824975
SSTable Compression Ratio: 0.20347134631246266
Number of keys (estimate): 39434
Memtable cell count: 18279
Memtable data size: 15897457
Memtable off heap memory used: 0
Memtable switch count: 1294
Local read count: 347016
Local read latency: 12.573 ms
Local write count: 109226238
Local write latency: 0.023 ms
Pending flushes: 0
Bloom filter false positives: 655
Bloom filter false ratio: 0.00000
Bloom filter space used: 97552
Bloom filter off heap memory used: 97376
Index summary off heap memory used: 26719
Compression metadata off heap memory used: 30700880
Compacted partition minimum bytes: 311
Compacted partition maximum bytes: 386857368
Compacted partition mean bytes: 6424107
Average live cells per slice (last five minutes):
1027.9502011434631
Maximum live cells per slice (last five minutes): 5722
Average tombstones per slice (last five minutes): 1.0
Maximum tombstones per slice (last five minutes): 1
