Hallo Jack, You have given a perfect example for wide row. Each reading from sensor creates new column within a row. It was also possible with Hector/CLI to have millions of columns within a single row. According to this page http://wiki.apache.org/cassandra/CassandraLimitations single row can have 2 billions columns.
How does this relate to CQL 3 and tables? I still do not understand it because: - it looks like driver loads all column names into memory - it looks to me that the 2 billions limitation from CLI is not valid anymore - Map and Set values do not support iterator Regards, Maciej On 19 May 2014, at 17:31, Jack Krupansky <j...@basetechnology.com> wrote: > You might want to review this blog post on supporting dynamic columns in > CQL3, which points out that “the way to model dynamic cells in CQL is with a > compound primary key.” > > See: > http://www.datastax.com/dev/blog/does-cql-support-dynamic-columns-wide-rows > > -- Jack Krupansky > > From: Maciej Miklas > Sent: Monday, May 19, 2014 11:20 AM > To: user@cassandra.apache.org > Subject: CQL 3 and wide rows > > Hi *, > > I’ve checked DataStax driver code for CQL 3, and it looks like the column > names for particular table are fully loaded into memory, it this true? > > Cassandra should support wide rows, meaning tables with millions of columns. > Knowing that, I would expect kind of iterator for column names. Am I missing > something here? > > > Regards, > Maciej Miklas
