Oracle數據庫中平均事務響應時間的計算公式
Oracle數據庫中平均事務響應時間的計算公式
注： 該計算公式取自：白鳝 <<oracle
優化日記>>，p316頁
Top 5 Timed Events
Event |
Waits |
Time(s) |
Avg Wait(ms) |
% Total Call Time |
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 last)
Event |
Waits |
%Time -outs |
Total 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
以"direct path read"這個等待事件為例子來計算：
A---"direct path read" 的 Total Wait Time（以ms來計算）為15555*1000=15555000ms
B---"direct path read" 的 Waits 為327284
C---"direct path read" 的 Waits /txn 為32.66
D---"direct path read" 的 % Total Call Time 為 86.4%=0.864
平均事務響應時間=A/B*C/D=15555000/327284*32.66/0.864=1796.584626 ms
