The calculation formula of average transaction response time in Oracle database

The calculation formula of average transaction response time in Oracle database

Note: This calculation formula is taken from: Eel with <<oracle Optimize journaling >> , p316 page

Top 5 Timed Events

Time Total call time

Event	Waits	(s)	AVG Wait (ms)	%	Wait Class
Direct Path Read	327,284	15,555	48	86.4	User I/O
CPU time		1,093		6.1
DB file Sequential read	283,101	509	2	2.8	User I/O
DB file Scattered read	99,520	180	2	1.0	User I/O
Enq:tx-row Lock contention	274	133	485	.7	Application

Wait Events

• S-second
• cs-centisecond-100th of a second
• ms-millisecond-1000th of a second
• us-microsecond-1000000th of a second
• Ordered by wait time desc, waits desc (idle events)

Total

Event	Waits	%time-outs	Wait time (s)	AVG Wait (ms)	Waits/txn
Direct Path Read	327,284	0.00	15,555	48	32.66
DB file Sequential read	283,101	0.00	509	2	28.25
DB file Scattered read	99,520	0.00	180	2	9.93
Enq:tx-row Lock contention	274	98.91	133	485	0.03
Log file Sync	6,791	0.00	93	14	0.68
Control file Sequential Read	16,168	0.00	91	6	1.61
Log file Parallel write	7,816	0.00	82	10	0.78
Name-service Call Wait	1,199	0.42	68	57	0.12

Take the "direct path read" as an example to calculate: A---"direct path read" Total  wait time (in ms) for 15555*1000=15555000MSB---"direct Path read "   Waits for 327284C---" direct path read "   waits/txn   for 32.66D---" direct path read "   % total Call Time is 86.4%=0.864 average transaction response times =a/b*c/d=15555000/327284*32.66/0.864=1796.584626 MS

The calculation formula of average transaction response time in Oracle database