by Angela Guess
A recent article discusses several trends in the world of databases and gives particular weight to the rise of NoSQL solutions. The article states, “The relational database model has dominated database design for a generation, a massive achievement in the world of IT where paradigm shifts are the rule, not the exception. However, as the example of Hadoop illustrates, the relational model is not suitable for all scenarios… Large-scale Web 2.0 sites – Facebook, Twitter and so on – as well as elastic cloud computing services simply could not scale economically across large clusters of computers. As a result, a variety of non-relational databases emerged and eventually the umbrella term ‘NoSQL’ became synonymous with these new technologies.”
It continues, “Within the NoSQL zoo, there are a several distinct family trees. Some NoSQL databases are pure key-stores without an explicit data model; many of these are based on Amazon’s Dynamo key-value store. Some are heavily influenced by Google’s BigTable database, which supports Google products such as Google Maps and Google Reader. Document databases store highly structured self-describing objects, usually in an XML-like format called JSON. Finally, graph databases store complex relationships such as those found in social networks.”
The article notes, “Within these four NoSQL families there are at least a dozen database systems of significance. Databases such as Riak, Cassandra, HBase, MongoDB and Neo4J are strong representatives of each category. NoSQL is a fairly imprecise term – it defines what the databases are not rather than what they are, and rejects SQL rather than the more relevant strict consistency requirement of the relational model. However imprecise the term may be, there’s no doubt that NoSQL databases represent an important direction in database technology.”
