Today Heroku launched a new PostGres database-as-a-service. PostGres is a popular open source SQL database server that serves as an alternative to MySQL and Oracle. It has a reputation as a mature, reliable and scalable database solution.

Heroku has long supported PostGres, but it’s now offering the database as a standalone service, meaning you don’t have to be running Ruby, Java or other applications on Heroku to take advantage of the company’s hosted database.

As part of the launch, Heroku has introduced a new interface for managing databases on its cloud service. The company promises to back-up databases continuously: “Every change to your data is written to write-ahead logs, which are shipped to multi-datacenter, high-durability storage. In the unlikely event of unrecoverable hardware failure, these logs can be automatically ‘replayed’ to recover the database to within seconds of its last known state.”

Pricing starts at $200 a month.

Databases can be the real bottleneck for many hosted applications, and offering a highly scalable hosted database makes a lot of sense. Salesforce.com (which owns Heroku) already offers an Oracle-based service called Database.com.

This is a quickly crowding space with many cloud database providers, including: Amazon Relational Database Service, ClearDB, Cloudant, the recently launched Google Cloud SQL, Xeround and soon Oracle Public Cloud. There are many others, but Heroku is pushing Postgres, which is less common, and already has a reputation for its PaaS.

What do you think? Will standalone databases become the next must-have feature for PaaS providers?