Cassandra : Row Cache & Memtable Q&A
Below, you will find 2 sets of questions and answers regarding Cassandra’s (now v0.7) Row Cache and Memtable. These were answered by Matthew Dennis at Riptano, a company that is actively developing both Cassandra and a management suite known as RipCord.
Questions
Hi!
I have a super column family. Writes either modify a column within a super column or add a super column to the super column family. I wonder how the row cache works.
A. How do writes interact with the Row Cache entries?
1. Do you update the row cache entry in place in order to keep it consistent with the SSTable?
2. Do you update it when the memtable is updated or when the memtable is flushed to the SSTable?
B. Also, is the Memtable appended to an SSTable when it is flushed or does it become its own SSTable?
nosql
sharadag
boredandroid