You probably are already familiar with my ash_wait_chains scripts that use CONNECT BY for walking through the blocking_session fields in ASH and report “wait chains”, signatures of complex waits involving other database sessions. Since ASH is “just” a history of V$SESSION, it’s sensible to assume that one could sample the current wait chains just by querying the GV$SESSION views, instead of summarizing history from ASH. And indeed it’s possible - here’s my Session-Wait-Chains sc...
