My best advice on this is, insert a bit of data into the tree, and then do a heap dump to calculate the extra overhead. It's unfortunately more than you would like from our testing.
On Tue, Oct 18, 2011 at 8:14 PM, Todd Nine <t...@spidertracks.com> wrote: > ** > Hi guys, > We've just built a K tree implementation in cassandra. We're going for > relatively "wide" nodes in our tree to minimize our tree depth and increase > our search times. Most of the links between parent/child nodes are longs. > We're ready to start tuning the size of K so that our most access paths in > our tree will be row cached in Cassandra. We're on Cassandra 0.8.7, and I > can't find any documentation regarding the actual memory size of the off > heap row cache. Can someone explain how much additional space will be used > when caching rows? For instance, if our links between nodes are all Longs, > and we have 100 children (cols), that gives us 900 bytes with a 0 byte > placeholder value. What is the additional overhead when using the off heap > storage? > > Thanks, > Todd >
