hi, >>> writing a new value to a row will invalidate the row cache for that value do you mean the entire row will be invalidate ? or just the column it was being updated ?
I was reading through http://planetcassandra.org/blog/post/cassandra-11-tuning-for-frequent-column-updates/ that seems to indicate it just write through it and not invalidate the entire row. if Cassandra invalidate the row cache upon a single column update to that row, that seems very inefficient. On Tue, Apr 29, 2014 at 4:43 AM, Jonathan Lacefield <jlacefi...@datastax.com > wrote: > Hello, > > > Iirc writing a new value to a row will invalidate the row cache for that > value. Row cache is only populated after a read operation. > http://www.datastax.com/documentation/cassandra/2.0/cassandra/operations/ops_configuring_caches_c.html?scroll=concept_ds_n35_nnr_ck > > Cassandra provides the ability to "preheat" key and page cache, but I > don't believe this is possible for row cache. > > Hope that helps. > > Jonathan > > > Jonathan Lacefield > Solutions Architect, DataStax > (404) 822 3487 > <http://www.linkedin.com/in/jlacefield> > > <http://www.datastax.com/cassandrasummit14> > > > > On Mon, Apr 28, 2014 at 10:27 PM, Jimmy Lin <y2klyf+w...@gmail.com> wrote: > >> I am wondering if there is any negative impact on Cassandra write >> operation, if I turn on row caching for a table that has mostly 'static >> columns' but few frequently write columns (like timestamp). >> >> The application will frequently write to a few columns, and the >> application will also frequently query entire row. >> >> How Cassandra handle update column to a cached row? >> does it update both memtables value and also the row cached row's >> column(which dealing with memory update so it is very fast) ? >> or in order to update the cached row, entire row need to read back from >> sstable? >> >> >> thanks >> >> >
