Installation Requirements
This section provides an overview of any special requirements you may need to know about in order to complete the PSQL installation. The following overview is intended to accompany the software and hardware requirements listed on the PSQL website for PSQL.
Access Rights
You must have full administrator-level rights on the machine where you install PSQL Server, PSQL Vx Server, or PSQL Workgroup.
No Other PSQL Database Engine Installed
You cannot install an edition of PSQL v12 on the same machine with another edition of PSQL v12. You must uninstall the other PSQL edition first. For example, PSQL Workgroup and PSQL Server cannot be installed on a machine at the same time.
Upgrading to PSQL v12
If upgrading from a previous version of PSQL, you must upgrade to the same edition of PSQL v12. For example, if you have a prior version of PSQL Workgroup, you must upgrade to PSQL Workgroup and not to PSQL Server. To change editions, you must first uninstall the prior version edition. The exception is that you may upgrade from PSQL Server to PSQL Vx Server, or from PSQL Vx Server to PSQL Server.
Operating Requirements
In a VM environment that supports live migration, an authorized PSQL instance—along with your application—can move from one host to another host with no impact to your end users. (Contrast this with a traditional client/server environment in which the physical server normally remains consistent. Clients may connect and disconnect, but they communicate with a dedicated server.)
Consistent Hostname
An authorized instance of PSQL can be moved to a different physical machine, or converted into a VM, or migrated to a different VM host. However the VM host name must remain the same. If the hostname must change, deauthorize the key for PSQL before performing the move, conversion or migration. Each instance of PSQL, including those that are cloned or copied for VMs, requires its own permanent key even if the host name is the same. See also, License Models in PSQL User's Guide.