Oracle資料庫中平均事務回應時間的計算公式,oracle回應時間
Oracle資料庫中平均事務回應時間的計算公式
註: 該計算公式取自:白鱔 <<oracle最佳化日記>>,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=15555000msB---"direct path read" 的 Waits 為327284C---"direct path read" 的 Waits /txn 為32.66D---"direct path read" 的 % Total Call Time 為 86.4%=0.864平均事務回應時間=A/B*C/D=15555000/327284*32.66/0.864=1796.584626 ms