We would like to know which open source DB would be the best choice for high performance and scalability ?

Would it be Postgres or MySQL ?

We are in process of discussing and finalizing WebNMS from a long time now and it is looking like a preferred choice...However, we would like to cut down our Oracle license cost and hence thinking of open source DB.

But before doing the costing design, it would be helpful to understand if postgres or MySQL (which one) will be a better choice...

Your inputs would be really helpful.

Thanks

Mangalam