There may be a Data Repository (DR) upgrade required when upgrading to DX Netops Performance Management 21.2.7
Release : 20.2
The Vertica version is updated in DX Netops Performance Management 21.2.3 and later.
Per the docuemantaion:
"Upgrade the data repository if you are upgrading from DX NetOps Performance Management 3.7, 20.2, or 21.2.2 and lower to DX NetOps Performance Management 21.2.3 or higher.
For more information, see New Features and Enhancements"