Process GEL script and Query erroring out post upgrade to 15.4

Products

• Clarity PPM SaaS
• Clarity PPM On Premise

Issue/Introduction

We are having problems with a process GEL script and query (used in a portlet) after upgrading to 15.4. I have attached the GEL script and NSQL query script for reference.

Cause

use of WM_CONCAT function has been removed from Oracle 12c.

Environment

Release: CODFSS99000-15.4.1-PPM SAAS FedRAMP-Sandbox-Small Environment
Component:

Resolution

CA PPM 15.3 and above will only support Oracle 12c or higher, and since 12c, Oracle have now removed the WM_CONCAT undocumented feature from their product.
Swapped out the WM_CONCAT function with LISTAGG. The queries and GEL script are running fine.