title: Is Cassandra a good candidate database for that must sustain over 100 read/write operations per second?
body: <p>Currently our system uses PostgreSQL, however we seem to have pushed the limit of its capabilities. Some of our tables need to handle over 100 read/write operations per second so it is probably time to scale horizontally across multiple machines.</p>
  
  <p>Have a lot of experience using GAE's Big Table. Big Table had rich options for querying. For example, queries were possible against list data fields. Cassandra is supposed to be based off of Big Table, but if I understand correctly, for Cassandra, we will actually have to custom-code a layer on top of Cassandra that uses and maintains index tables.</p>
  
  <p>Would be great if there was an open source database available for which we did not have to build our own custom logic for maintaining index tables, zig-zag merge joins, etc...</p>
  
  <p>Is Cassandra a good candidate here? Or are there ones that might be considered better?</p>