That's not necessarily true. You don't need to split them into separate keyspaces, but separate tables may have some advantages. For example, in Cassandra 2.1, compaction and index summary management are optimized based on read rates for SSTables. If you have different read rates or patterns for the two types of data, it will confuse/eliminate these optimizations.
If you have two separate sets of data with (potentially) two separate read patterns, don't put them in the same table. On Thu, Nov 13, 2014 at 11:08 AM, Jonathan Haddad <j...@jonhaddad.com> wrote: > Performance will be the same. There's no performance benefit to using > multiple keyspaces. > > > On Thu Nov 13 2014 at 8:42:40 AM Li, George <guangxing...@pearson.com> > wrote: > >> Hi, >> we use Cassandra to store some association type of data. For example, >> store user to course (course registrations) association and user to school >> (school enrollment) association data. The schema for these two types of >> associations are the same. So there are two options to store the data: >> 1. Put user to course association data into one keyspace, and user to >> school association data into another keyspace. >> 2. Put both of them into the same keyspace. >> In the long run, such data will grow to be very large. With that in mind, >> is it better to use the first approach (having multiple keyspaces) for >> better performance? >> Thanks. >> >> George >> > -- Tyler Hobbs DataStax <http://datastax.com/>
