2026-03-12 20:23:15

vdh/wait_chains.sql

@@ -0,0 +1,84 @@
+set pages 50000
+set lines 200
+set heading off
+
+column w_proc format a50 tru
+column instance format a20 tru
+column inst format a28 tru
+column wait_event format a50 tru
+column p1 format a16 tru
+column p2 format a16 tru
+column p3 format a15 tru
+column seconds format a50 tru
+column sincelw format a50 tru
+column blocker_proc format a50 tru
+column fblocker_proc format a50 tru
+column waiters format a50 tru
+column chain_signature format a100 wra
+column blocker_chain format a100 wra
+
+select
+  *
+from 
+  ( select
+      'Current Process: ' || osid w_proc, 
+      'SID ' || i.instance_name instance,
+      'INST #: ' || instance inst,
+      'Blocking Process: ' || decode(blocker_osid,null,'<none>',blocker_osid) || ' from Instance ' ||blocker_instance blocker_proc,
+      'Number of waiters: ' || num_waiters waiters,
+      'Final Blocking Process: ' || decode(p.spid,null, '<none>', p.spid) || ' from Instance ' || s.final_blocking_instance fblocker_proc,
+      'Program: ' ||p.program image,
+      'Wait Event: ' || wait_event_text wait_event, 
+      'P1: ' || wc.p1 p1, 
+      'P2: ' ||wc.p2 p2, 
+      'P3: ' ||wc.p3 p3,
+      'Seconds in Wait: ' || in_wait_secs seconds, 
+      'Seconds Since Last Wait: ' || time_since_last_wait_secs sincelw,
+      'Wait Chain: ' || chain_id || ': ' || chain_signature chain_signature,
+      'Blocking Wait Chain: ' || decode(blocker_chain_id,null, '<none>',blocker_chain_id) blocker_chain
+    from
+      v$wait_chains wc,
+      gv$session    s,
+      gv$session    bs,
+      gv$instance   i,
+      gv$process    p
+    where 
+      wc.instance = i.instance_number (+)
+      and ( wc.instance = s.inst_id (+) and wc.sid = s.sid (+)
+            and wc.sess_serial# = s.serial# (+)
+          )
+      and ( s.inst_id = bs.inst_id (+) 
+            and s.final_blocking_session = bs.sid (+)
+          )
+      and ( bs.inst_id = p.inst_id (+) 
+            and bs.paddr = p.addr (+)
+          )
+      and ( num_waiters > 0
+            or ( blocker_osid is not null
+                 and in_wait_secs > 10 
+               )
+          )
+    order by 
+      chain_id,
+      num_waiters desc
+  )
+where
+    rownum < 101
+;
+
+set heading on
+
+column w_proc clear
+column instance clear
+column inst clear
+column wait_event clear
+column p1 clear
+column p2 clear
+column p3 clear
+column seconds clear
+column sincelw clear
+column blocker_proc clear
+column fblocker_proc  clear
+column waiters clear
+column chain_signature clear
+column blocker_chain clear