3 ms·
Cassandra has an append-only log file during operation but unlike a RDBMS it's not just used for transaction replay, so you're half write. Cassandra periodicall
by snuxoll 10y ago
Cassandra has an append-only log file during operation but unlike a RDBMS it's not just used for transaction replay, so you're half write. Cassandra periodically compacts the log and writes SSTable's to disk, but newer data and tombstones are stored in the log for a while which as you surmised does have a performance hit.
- ddorian43 10y agoPerformance hit is not from the log though, but from having non-reading-writes (and ttls). So you have to look other versions too on disk for latest value. I think newer data and tombstones would stay for a while in sstables, not in the log.