Does the core licensing model apply the same for SQL Server 2017, 2019, 2022 and 2025?

Yes. The basic principle of core-based licensing (per core) is the same for SQL Server 2017, 2019, 2022 and 2025: computing power is licensed in the form of CPU cores, not access via user or device CALs. As soon as the environment is correctly licensed per core, no SQL Server CALs are required.

What are the minimum requirements for physical servers (per core)

In the case of physical servers, minimum values apply regardless of the actual number of cores installed. At least 4 core licenses must be applied per physical processor (socket). In addition, a minimum licensing requirement of 16 core licenses applies per physical server. If the actual number of cores exceeds these minimum values, the existing physical cores must be fully licensed.

What are the minimum requirements for virtual machines (VMs)

When virtual machines are specifically licensed per VM, the minimum approach is typically a minimum number of core licenses per VM. It is crucial that the licensing does not become "arbitrarily small" just because a VM is technically assigned a small number of vCores. In practice, the correct allocation of VM licensing and the minimum approaches is therefore important so that the licensing is not later assessed as "too small".

What does this mean for SQL Server Standard versus Enterprise?

In the core model, the licensing logic remains the same, but the editions can have functional limits. SQL Server Standard is limited in its usable computing capacity compared to Enterprise. This concerns the maximum usable resources of the edition, not the basic obligation to comply with minimum cores or to fully license physical cores as soon as you go beyond the minimum values.

What role does Software Assurance (SA) play in practice?

Software Assurance can provide additional flexibility and rights in operation, especially in virtualized environments and for the mobility of workloads. Without SA, certain more flexible deployment models are often limited in practice, which means that licensing is typically thought of more in terms of allocation to the physical host and its physical cores. The decisive factor remains: The selected license model and the form of operation used (physical, VM, cluster, move patterns) must fit together.

What are the typical mis-purchases with core licensing and how do you avoid them?

A common mis-purchase is the assumption that a very small VM can always be licensed "minimally", although minimum rates and packaging logics apply; this can be avoided by carefully checking the minimum rate per VM and the real lower license limit before purchasing.

A second mistake is to choose Standard even though the Standard edition is functionally or capacity-limited; this can be avoided by clarifying in advance whether the planned load and the required features are covered in Standard.

A third mistake is to plan core licenses too tightly because only minimum values are considered, even though the server has more physical cores; this can be avoided by taking the actual number of cores of the host or the target architecture (host/VM) as a basis and only then looking at minimum values.

A fourth mistake is to plan virtualization scenarios without the appropriate rights; this can be avoided by determining in advance whether you want to license specific VMs or cover the host completely, and whether additional rights (e.g. through SA) are required for this.

Regardless of the size of the virtual machine, at least 4 core licenses are required per VM.

If more than four vCores are assigned, each additional vCore must also be licensed.