The C2090-318 certification evaluates senior DB2 System Administrators for z/OS on their proficiency in managing complex database environments across the DB2 12 architecture. Candidates must demonstrate advanced technical competency in installation, migration, and configuration of data sharing groups, alongside expert-level proficiency in storage management, subsystem parameters, and performance tuning utilizing WLM, buffer pools, and RID pool optimization. The curriculum mandates deep knowledge of advanced recovery procedures, utility execution, security protocols including RACF integration, and connectivity management via DDF. Participants must also exhibit mastery of SQL performance analysis, log management, and robust data integrity maintenance within high-availability sysplex mainframe environments.