Licensing: 

The previous articles talked about Branding with a multitenant application. This article discusses Licensing next. 

Licensing depends on the application, users and tenants. Some applications enforce licensing to be based on users or logins but not servers. Licensing also affects purchasing model.   

There are several ways to license a multitenant store. For example, managed database instances can come with licensing on per core basis or per user basis or a combination of server plus client access licenses (CAL). The editions of the product for these licenses can vary from Enterprise, Standard-per core, Standard- server + CAL, Developer, Web, and Express.  
 
There are two purchasing models:  
1) Virtual v-core based purchasing model - this model provides a choice between a provisioned compute tier and a serverless compute tier. With the provisioned compute tier, the amount of computer resources is always provisioned for the workload. With the serverless compute tier, the autoscaling of the compute resources is specified instead. With autoscaling, the databases are paused and resumed with charges only for storage during period of inactivity. 

2) the database transaction unit-based purchasing model – this model provides bundled compute and storage packages balanced for common workloads. The compute sizes are declared in DTUs for single databases and elastic DTUs for elastic pools. The vCore based model allows us to independently choose compute and storage resources. Customers prefer DTU-based for simple, preconfigured resource options and vCore-based for value flexibility, control, and transparency. 

Storage costs are calculated differently based on each purchasing model. Storage is included in the price of the DTU. It is possible to add extra storage in the standard and premium tiers of a cloud SQL database. 

When the number of servers or the number of users is large, volume licensing options might be available. This is the practice of selling a license authorizing one piece of software to be used on a large number of computers or by a large number of users. Software training for volume licensing customers might be made available by way of training and certification solutions. A customized software purchase program that grants the discounted access to training and certification solutions.