What is it?
Sun may own MySQL, but the company has put more resources into integrating the rival open source database PostgreSQL into its Solaris operating system.
Traditionally PostgreSQL has been regarded as the heavyweight of the two, the Oracle equivalent, in contrast to the cheap and cheerful, SQL Server-like MySQL. PostgreSQL has been the choice for on line transaction processing, MySQL for websites.
The article continues at http://www.computerweekly.com/Articles/2009/02/17/234473/hot-skills-postgresql.htm