Databases Reference
In-Depth Information
Figure A-6. Keys form a natural index through rows in a column family database
Column family databases are distinguished from document and key-value stores not
only by their more expressive data model, but also by their operational characteristics.
Apache Cassandra, for example, which is based on a Dynamo-like infrastructure, is
architected for distribution, scale, and failover. Under the covers it uses several storage
engines that deal with high write loads—the kind of peak write loads generated by
popular interactive TV shows.
Overall, column family databases are reasonably expressive and operationally very
competent. And yet they're still
aggregate stores
, just like document and key-value
databases, and as such, lack joins. Querying them for insight into data at scale requires
processing by some external application infrastructure.
