PSQL Vx Server 12 and PSQL v12 Server products are identical in core functionality, but they differ on the way licenses are handled. First off, you MUST use the PSQL Vx licensing model if you are using any middleware, web server, or SaaS environments. If you do not have any of these requirements, then you can go either way. PSQL v12 is licensed per concurrent user, while PSQL Vx Server 12 is licensed based on the size of the database being accessed.
PSQL Vx Server 12 licenses are available in 4 sizes: Small (5GB), Medium (20GB), Large (50GB) and SuperSize (Unlimited). Licenses are available in either "base" licenses, of which you can have only one on any given server, and data size increase (DSI) licenses in various sizes, which can be used to increase the capacity of your PSQL Vx license.
For the base licenses, upgrade discounts may be available depending on your source engine and user count.
You can find more information about this software on our main product page
You can find copies of license documents prior to your purchase on our licensing page
If the above button doesn't work, you may be using Internet Explorer. Try this link