On Thu, Sep 15, 2011 at 3:05 PM, mcasandra <mohitanch...@gmail.com> wrote: > With Leveldb is it going to make reads slower
No. Qualified: compared to "major compaction" under the tiered strategy, leveled reads will usually be a little slower for update-heavy loads. (For insert-mostly workloads compaction doesn't really matter.) But major compaction is not practical in production; you want something that gives consistently good performance, rather than good performance once a day or once a week and then degrades quickly. > my understanding is it > will create more smaller files Yes. > and updates could be scattered all over > before compaction? No, updates to a given row will be still be in a single sstable. > Also, when memtables are flushed, does it create small > files too since memtable size would generally be bigger than 2-4MB? Level0 (newly flushed) sstables are not size-limited. This is one of a handful of differences we have over leveldb itself, which remains a good overview (http://leveldb.googlecode.com/svn/trunk/doc/impl.html). -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com
