The cloud database market continues to solidify as Google puts a price tag on its Cloud SQL offering. With actual charges to begin on June 12th, the move finally gives developers a way to see what they’ll be spending on Cloud SQL, but comparing Google’s offering to Amazon, Microsoft and others might still be a bit tricky.

Google’s Cloud SQL is MySQL-based and is intended to be used with Google App Engine (GAE). Google’s pricing structure is very simple, though not as comprehensive or as expandable as Amazon or others.

Google has two billing plans: a package plan and a per-use plan. The package plan has four tiers, each of which includes a set amount of RAM, storage and I/O per day. For instance, Google charges $1.46 per day for the D1 tier, which has .5GB of RAM, 1GB of storage and 850,000 I/O requests. The top package (D8) includes 4GB of RAM, 10GB storage and 8 million I/O requests for $11.71 per day.

The same instances are available on an on-demand basis, starting at $0.10 per hour, with storage and I/O extra.

The cheapest package from Google, then, runs about $45 a month and the most expensive runs about $357. That doesn’t count any overages for I/O or storage.

Sizing Up Google’s Pricing

Trying to compare Google pricing with Amazon, Azure or databases offered with PaaS services such as Heroku and Engine Yard is tricky, at best. Heroku’s database offerings start at $50 per month, but the specs for its database differ considerably from the other providers. For example, Heroku features data clips for developers, and the hstore extension for key/value data storage.

Amazon’s DB instances seem to be a bit more powerful than Google Cloud SQL instances, and Amazon has features that Google Cloud SQL doesn’t. For instance, Amazon’s Small DB instance has 1.7 GB of RAM and has the equivalent of a single CPU. You’re also limited to Google App Engine supported languages, Python and Java.

Developers can choose between 5GB and 1TB of storage (the max for Google is 10GB storage). The Small DB instance runs about $77 a month, if it’s on-demand. But, choosing a one-year reserved instance brings that down to about $45 a month. The pricing, then, seems to line up for the “small” instances for Amazon RDS and Google Cloud SQL, but Google has fewer features and what looks to be less compute power.

But if you’re using GAE, then Cloud SQL is the natural choice – so it’s nice to see Google finally getting this into developers’ hands. If you’re using GAE and Cloud SQL, we’d love to hear what you think.