On Sun, Dec 13, 2009 at 7:28 PM, Stu Hood <stuart.h...@rackspace.com> wrote: > With 248G per box, you probably have slightly more than 1/2 billion items? > > One current implementation detail in Cassandra is that it loads 128th of the > index into memory for faster lookups. This means you might have something > like 4.5 million keys in memory at the moment. > > The '128' value is a constant at SSTable.INDEX_INTERVAL. You should be able > to recompile with '1024' to allow for an 8 times larger database, but > understand that this will have a negative effect on your read performance.
Is there a reason for having this as an hardcoded value instead of configuration value? It seems to me that it is a kind of lookup time/memory usage tradeoff threshold that could be tweaked by users, or is there a reason to not allow it?