Can PostgreSQL pickup where MySQL left off?

EnterpriseDB, a provider of enterprise-class products and services based on PostgreSQL, today announced Postgres Plus Cloud Server, which the company has billed as "a full-featured, Oracle-compatible, enterprise-class PostgreSQL database-as-a-service for public and private clouds with support for Amazon EC2, Eucalyptus, Rackspace, and GoGrid."

We've seen other database-as-a-service offerings come on the scene from the likes of Salesforce.com's Database.com, Amazon RDS, as well as from startup Xeround. But they're not based on PostgreSQL, which has had years of hardening and development by a committed community. The other databases are not "Oracle compatible," which could serve as a competitive advantage for Postgres Plus Cloud Server as it promises to move Oracle applications to the cloud at a fraction of the cost of Oracle licenses. If true, that's compelling.

But what of NoSQL databases such as Cassandra and MongoDB? According to EnterpriseDB CEO Ed Boyajian, the technologies should all play well together. The main thing is to have a platform that users feel comfortable won't suddenly go from open- to closed-source, which some believe Oracle is already working toward.

Article after article blames Oracle for its bad stewardship of open source, whether it be MySQL or Java. Blogger Dana Blankenhorn even pointed out that in Oracle's legal struggles with Google, the company is "arguing for a new understanding of copyright that would make all software, even open source, de-facto proprietary"--a stance unlikely to gain favor with the open-source community.

Interest in PostgreSQL has risen recently. There were reports earlier this month of Apple dumping MySQL for PostgreSQL in Mac OS X Lion Server. And back in June, blogger Matt Asay wondered aloud if Red Hat was planning to acquire EnterpriseDB--the "enterprise PostgreSQL company"--as a power move to combat Oracle head-on.

It's clear that non-relational databases are having a big impact on the way we build applications now, but the database remains a multibillion-dollar opportunity, with the vast majority of the revenue going toward the development and management of relational databases.

The big question is whether or not relational databases such as PostgreSQL will make the jump to the cloud in a meaningful way or if NoSQL will rule. Odds are we'll see a push from both sides, but with developers holding such heavy sway these days, the platform that is best appointed and most open is likely to win favor.