I think maybe one reason is that Cassandra will also log the operation into log files, and the log contains the records.
2010/5/25 casablinca126.com <casabli...@126.com>: > hi Sharan, > what's the replication factor are you using ? > > regards, > Cao Jiguang > > > 2010-05-25 > ________________________________ > casablinca126.com > ________________________________ > 发件人: sharanabasava raddi > 发送时间: 2010-05-25 13:46:38 > 收件人: user@cassandra.apache.org > 抄送: > 主题: Why Cassandra is "space inefficient" compared to MySQL? > Hi all, > Am running "Cassandra" on Windows XP (single node) machine. > I have made insertion of about "10 million" records into "Cassandra" , and > it took around 90 minutes to insert and 8GB of space. > For the same number of records MySQL will take "3 GB" space. > > Could you please tell me why? > And please Give me the complete documentation for running Thrift API with > Java to talk to Cassandra in "Red Hat Linux". > > > > > > Thanks, > Sharan > > > -- Best Regards Jeff Zhang