Have to help out on a design without specifics but here is some advice based on the limited information
Primary key : yes, must be cluster unique. TimeUUID or UUID….PlayOrm has very unique TimeUUID like keys as in this one 7AL2S8Y.b1 (b1 is the hostname and the prefix is a "unique" timestamp but generated to a shorter string(ah, nice readable primary keys). There are some patterns you can look into here that may help https://github.com/deanhiller/playorm/wiki/Patterns-Page If you can partition your data virtually, it may help a lot so you can query into the partitions. Later, Dean From: "stephen.m.thomp...@wellsfargo.com<mailto:stephen.m.thomp...@wellsfargo.com>" <stephen.m.thomp...@wellsfargo.com<mailto:stephen.m.thomp...@wellsfargo.com>> Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>> Date: Tuesday, December 11, 2012 2:49 PM To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>> Subject: Primary/secondary index question / best practices? m my reading, it seems like I need a UUID column that will be my primary index, and then I should set up secondary indexes on the 8-10 primary search columns. Am I understanding this correctly? Any advice you can offer on this would be tremendously helpful. I’m quite limited in how specific I can be about the data, of course.