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Home -> Community -> Usenet -> c.d.o.server -> log file sync , log file parallel write
Hi ,
my top wait list shows 2 events , log file sync and log file parallel write in 1 hour.
During this time , the db server created 370,594 bytes redo per second.
the docs say that high value of both log file sync and log file
parallel write indicates io problem .
How can we decide whether below numbers are close to each other or not?
If it is not possible to change the application and eliminate the unnecessary commits (such as sap) , how can lg file sync be decreased?
Kind Regards
Load Profile
~~~~~~~~~~~~ Per Second Per
Transaction
---------------
---------------
Redo size: 370,594.95
2,966.21
Logical reads: 39,925.48
319.56
Block changes: 2,447.17
19.59
Physical reads: 67.83
0.54
Physical writes: 433.47
3.47
User calls: 880.52
7.05
Parses: 275.49
2.21
Hard parses: 1.92
0.02
Sorts: 553.98
4.43
Logons: 0.29
0.00
Executes: 5,303.67
42.45
Transactions: 124.94
% Blocks changed per Read: 6.13 Recursive Call %: 89.20
Rollback per transaction %: 0.68 Rows per Sort: 11.52
Instance Efficiency Percentages (Target 100%)
Buffer Nowait %: 99.99 Redo NoWait %: 99.95
Buffer Hit %: 99.83 In-memory Sort %: 100.00
Library Hit %: 100.25 Soft Parse %: 99.30
Execute to Parse %: 94.81 Latch Hit %: 99.03
Parse CPU to Parse Elapsd %: 15.58 % Non-Parse CPU: 98.01
Shared Pool Statistics Begin End
------ ------
Memory Usage %: 94.91 95.30
% SQL with executions>1: 87.78 87.31
Top 5 Timed Events
Event Waits Time (s)Ela Time
-------------------------------------------- ------------ -----------
--------
log file sync 483,596 194,940
64.17
latch free 656,366 46,963
15.46
db file sequential read 232,327 31,051
10.22
CPU time 20,846
6.86
log file parallel write 201,538 2,810
.93
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Received on Mon Dec 18 2006 - 15:28:06 CST
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