2026-03-12 20:23:15

tpt/ash/evet_hist_cell.sql

@@ -0,0 +1,38 @@
+-- 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.
+
+-- this scripts uses "ASH math" by Graham Wood, Uri Shaft and John Beresniewicz for
+-- estimating the event counts (and average durations)
+
+COL evh_event HEAD WAIT_EVENT for A50 TRUNCATE
+COL evh_graph HEAD "Awesome|Graphic" JUST CENTER FOR A12
+COL pct_evt_time HEAD "% Event|Time"
+COL evh_est_total_ms HEAD "Estimated|Total ms"
+COL evh_millisec HEAD "Wait time|bucket ms+"
+COL evh_event HEAD "Wait Event"
+COL evh_sample_count HEAD "Num ASH|Samples"
+COL evh_est_event_count HEAD "Estimated|Total Waits"
+
+BREAK ON evh_event SKIP 1
+
+SELECT 
+    event evh_event
+  , CASE WHEN time_waited = 0 THEN 0 ELSE TRUNC(POWER(2,TRUNC(LOG(2,time_waited/1000)))) END evh_millisec
+  , COUNT(*)  evh_sample_count
+  , ROUND(SUM(CASE WHEN time_waited >= 1000000 THEN 1 WHEN time_waited = 0 THEN 0 ELSE 1000000 / time_waited END),1) evh_est_event_count
+  , ROUND(CASE WHEN time_waited = 0 THEN 0 ELSE TRUNC(POWER(2,TRUNC(LOG(2,time_waited/1000)))) END * COUNT(*),1) evh_est_total_ms
+  , ROUND ( 100 * RATIO_TO_REPORT( CASE WHEN time_waited = 0 THEN 0 ELSE TRUNC(POWER(2,TRUNC(LOG(2,time_waited/1000)))) END * COUNT(*) ) OVER (PARTITION BY event) , 1 ) pct_evt_time
+  , '|'||RPAD(NVL(RPAD('#', ROUND (10 * RATIO_TO_REPORT( CASE WHEN time_waited = 0 THEN 0 ELSE TRUNC(POWER(2,TRUNC(LOG(2,time_waited/1000)))) END * COUNT(*) ) OVER (PARTITION BY event)), '#'),' '), 10)||'|' evh_graph
+FROM 
+    V$ACTIVE_SESSION_HISTORY 
+    --dba_hist_active_sess_history
+WHERE 
+    regexp_like(event, '&1') 
+AND sample_time > SYSDATE - 1
+AND time_waited > 0  -- TODO
+GROUP BY 
+    event
+  , CASE WHEN time_waited = 0 THEN 0 ELSE TRUNC(POWER(2,TRUNC(LOG(2,time_waited/1000)))) END -- evh_millisec
+ORDER BY 1, 2
+/
+