Column-family stores

A Column-family store is another example of a very task-oriented type of solution. The data model is a bit more complex than the Key-value store, as it now includes the concept of a very wide, sparsely populated table structure that includes a number of families of columns that specify the keys for this particular table structure. Like the Dynamo system, Column-family stores also originated from a very specific need of a very specific company (in this case, Google), who decided to roll their own solution. Google published their BigTable paper in 2006 at the Operating Systems Design and Implementation (OSDI) symposium. The paper not only started a lot of work within Google, but also yielded interesting open source implementations such as Apache Cassandra and HBase. In many cases, these systems are combined with batch-oriented systems that use Map/Reduce as the processing model for advanced querying: