“Replication is one of the most popular features used in RDBMS’s
today. Replication is used for disaster recovery purposes (i.e.
backup or warm stand-by servers), reporting systems where query
activity is offloaded onto another machine to conserve resources on
the transactional server, and scale-out architectures that use
sharding or other methods to increase overall query performance and
data throughput.“Replication is not restricted to only the major proprietary
databases; open source databases such as MySQL and PostgreSQL also
offer replication as a feature. While MySQL has offered built-in
replication for a number of years, PostgreSQL replication used to
be accomplished via community software that was an add-on to the
core Postgres Server. That all changed with the release of version
9.0 of PostgreSQL, which now offers built-in streaming replication
that is based on its proven write ahead log technology.“With the two most popular open source databases now providing
built-in replication, questions are being asked about how they
differ in their replication technologies. What follows is a brief
overview of both MySQL and PostgreSQL replication, with a brief
compare and contrast of the implementations being performed
immediately afterwards.”