In Viewpoint Query-Monitor, for a particular session we can check the cpu skew and also the highest and average cpu.
If I want to check this from database, then which table and column shall I refer, is it DBQLogTbl or AMPUsageV view or anything else?
for the near-real-time data, you might want to check MonitorSession:
SELECT * FROM TABLE (SYSLIB.MonitorSession(-1,'*',0));
for the history data, the DBQL is the most probable choice.