Global Positioning System Reference
In-Depth Information
The remainder of this chapter is organised as follows. The next section
presents an overview of NoSQL systems. Then, the desirable characteristics
of a NoSQL system with spatial data support are highlighted. The following
sections focus on different NoSQL spatial systems: CouchDB, MongoDB,
BigTable, and Neo4j. Finally, we conclude the chapter and compare the
several systems addressed herein.
NoSQL Systems
NoSQL is a term in information technology that describes database
management systems, which depart from classic Relational DBMS altogether,
or in some parts. The term was fi rst used in 1998 for lightweight open source
databases that did not use SQL (Structured Query Language) as a database
language (Strozzi 2007). The name “NoSQL” could indicate that these
databases do not support SQL, but in this case it actually means “Not Only
SQL” (NoSQL 2013). During the past years, the term has been widely used
to designate a class of database systems that offer an alternative solution to
the Relational Model (Codd 1970) in terms of availability, scalability, and
performance for the management of large amounts of data. The goal of
NoSQL systems is not to replace RDBMs as a whole, but to be used in cases
in which more fl exibility is required with respect to the database structure
(Sadalage and Fowler 2012; Redmond and Wilson 2012).
A Brief History
Google's BigTable (Chang et al. 2008) and Amazon's Dynamo (DeCandia et
al. 2007) seem to be the starting point for the NoSQL movement. Many of
the design decisions and principles used in these systems can be found in
later ones. Google's BigTable was launched in 2004 as a high-performance
proprietary database offering scalability and availability. Its original
proposal was to relax the structure used by the Relational Model. Amazon's
Dynamo was launched in 2007 as a high-performance non-relational
database system, to be used by Amazon Web Services. In 2008, Cassandra
was presented as a highly scalable distributed database system, designed
by Facebook developers to deal with large amounts of data (Lakshman and
Malik 2009). Cassandra joined the distributed systems technologies from
Dynamo and the data model from Google's BigTable. In the beginning of
2010, Twitter replaced MySQL with Cassandra (Lai 2010). At the same time,
Apache CouchDB was launched, an open-source NoSQL system. It allowed
applications to store data without having to adhere to the structure of a
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