If I understand you correctly, I think I have a decent example. I have a ColumnFamily which models user preferences for a "site" in our system:
UserPreferences : { 123_EDD43E57589F12032AF73E23A6AF3F47 : { favorite_color : red, ... } } I structured it this way because we have a lot of "sites" to which a user could create preferences for, so the site_id is prepended to the value of a session_id therefore you always need two pieces of information to enforce that a given record belongs to a specific "site". The site_id is always an integer and the session_id is always a 32 char string so sticking an underscore between them makes validatable parsing and construction trivial. The bloom filtering behind the key lookups also make checks for existence extremely fast. Note: I feel compelled to mention this is not a typical use case that I think would generally warrant anything outside of an RDBMS. However, In our system writes to this preference "table" can burst up to several thousand a second. Thus the need for the predictable write performance of Cassandra. Cheers, Nate On Tue, Feb 2, 2010 at 9:50 AM, Erik Holstad <erikhols...@gmail.com> wrote: > Sorry that there are a lot of questions from me this week, just trying to > better understand > the best way to use Cassandra :) > > Let us say that you know the length of your key, everything is standardized, > are there people > out there that just tag the value onto the key so that you don't have to pay > the extra overhead > of the second byte[]? > > -- > Regards Erik >