2026-03-12 20:23:15

tpt/tools/session_wait_monitor.sql

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+-- Copyright 2018 Tanel Poder. All rights reserved. More info at http://tanelpoder.com
+-- Licensed under the Apache License, Version 2.0. See LICENSE.txt for terms & conditions.
+
+--
+-- SCRIPT:  session_wait_monitor.sql
+--
+-- PURPOSE: Creates one table and one procedure for logging v$session_wait 
+--          wait statistics. Running this script does not enable the logging,
+--          the usage examples are below.
+--
+-- REQUIREMENTS:
+--          Read access on V$SESSION_WAIT
+--          Execute right on DBMS_LOCK
+--
+-- USAGE:
+--          EXEC session_wait_monitor ( <wait_name>, <from_time>, <to_time>, <sleep_time> )
+--
+--          wait_name = the name of wait event to be sampled, % and _ wildcards allowed, default %
+--          from_time = time when sampling should start (the procedure sleeps until then), default SYSDATE
+--          to_time   = time when sampling should end (procedure quits then), default SYSDATE + 1 minute
+--          sleep_time= time to sleep between samples, default 5 seconds
+--
+--          once the procedure returns, query session wait samples:
+--
+--          SELECT * FROM session_wait_hist ORDER BY sample_time ASC, cnt DESC;
+--
+-- EXAMPLES:
+-- After the table and procedure have been created, use following commands to:
+--
+-- 1) Sample all session waits for 60 seconds from now, at 5 second intervals (few idle waits are not sampled):
+--
+--      EXEC session_wait_monitor
+--
+-- 2) Sample only buffer busy waits from 9 pm to 9:10 pm on 2007-10-19 (3 second sampling interval)
+--
+--      EXEC session_wait_monitor('buffer busy waits', timestamp'2007-10-19 21:00:00', timestamp'2007-10-19 21:10:00', 3)
+--
+-- 3) Sample all events containing "db" from now up to end of today:
+--      
+--      EXEC session_wait_monitor('%db%', sysdate, trunc(sysdate)+1)
+--
+
+create table session_wait_hist(
+    sample_time date            not null, 
+    event       varchar2(100)   not null, 
+    p1          number,
+    p2          number, 
+    p3          number, 
+    cnt         number
+);
+
+create or replace procedure session_wait_monitor ( 
+                    wait_name   in varchar2 default '%', 
+                    from_time   in date     default sysdate,
+                    to_time     in date     default sysdate + 1/24/60,
+                    sleep_time  in number   default 5
+) 
+    authid current_user as
+begin
+    
+    while sysdate < from_time loop
+        dbms_lock.sleep(sleep_time);    
+    end loop;
+
+    while sysdate between from_time and to_time loop
+
+        insert into 
+            session_wait_hist       
+        select 
+            sysdate, event, p1, p2, p3, count(*) cnt 
+        from 
+            v$session_wait 
+        where 
+            state = 'WAITING' 
+        and event like wait_name
+        and event not in (
+            'SQL*Net message from client',
+            'pmon timer',
+            'rdbms ipc message',
+            'smon timer',
+            'wakeup time manager'
+        )
+        group by 
+            event, p1, p2, p3;
+
+        commit;
+        
+        dbms_lock.sleep(sleep_time);    
+    
+    end loop;
+    
+end;
+/