> And also stored entirely for each UPDATE. Change one element, re-serialize the whole thing to disk.
Is this true? I thought updates (adds, removes, but not overwrites) affected just the indicated columns. Isn't it just the reads that involve reading the entire collection? DS docs talk about reading whole collections, but I don't see anything about having to overwrite the entire collection each time. That would indicate a read then write style operation, which is antipatterny. > When you query a table containing a collection, Cassandra retrieves the collection in its entirety http://www.datastax.com/documentation/cql/3.0/cql/cql_using/use_set_t.html On Fri, Jan 2, 2015 at 11:48 AM, Robert Coli <rc...@eventbrite.com> wrote: > On Thu, Jan 1, 2015 at 11:04 AM, DuyHai Doan <doanduy...@gmail.com> wrote: > >> 2) collections and maps are loaded entirely by Cassandra for each query, >> whereas with clustering columns you can select a slice of columns >> > > And also stored entirely for each UPDATE. Change one element, re-serialize > the whole thing to disk. > > =Rob >
