Please read this: http://www.allthingsdistributed.com/2007/10/amazons_dynamo.html
On Wed, Apr 7, 2010 at 1:27 PM, S Ahmed <sahmed1...@gmail.com> wrote: > Just reading up on boonfilters, few questions. > > Basically boonfilters let give you a true/false if a particular key exists, > and they *may* give you a false positive i.e. they key exists but never a > false negative i.e. the key doesn't exist. > > The core of boonfilters is its hashing mechanism that marks the in-memory > matrix/map if the key exists. > > 1. Is the only place boonfilters are used in Cassandra is when you want to > see if a particular key exists in a particular node? > > 2. Are boonfilters a fixed size, or they adjust as to the # of keys? any > example size? > > 3. Boonfilters don't give false negatives: > So you hit a node, and perform a lookup in the boonfilter for a key. It > says "yes", but when you do a lookup the object returned is null, so then > you flag that this node needs this particular key during replication. > > > Have I grasp this concept? > > Really loving this project, learning allot from the code. It would be great > if someone could do a walkthrough of common functionality in a detailed way > :) >
