Oracle Database Discussions

Please suggest me, how to fix below issues but as per my application i cant reduce commits.

my redo log size is 50MB and 2 groups per instance , log switch freqency is very high duing the peak time , it is almost 166 per hour and size is 8300 MB, If i increase redo size , will it be ok?

WORKLOAD REPOSITORY report for

DB Name DB Id Instance Inst Num Startup Time Release RAC
------------ ----------- ------------ -------- --------------- ----------- ---
XXXXXX 4064028508 XXXX 1 18-Jan-12 18:38 11.2.0.2.0 YES

Host Name Platform CPUs Cores Sockets Memory(GB)
---------------- -------------------------------- ---- ----- ------- ----------
XXXXXXXX AIX-Based Systems (64-bit) 32 8 18.00

Snap Id Snap Time Sessions Curs/Sess
--------- ------------------- -------- ---------
Begin Snap: 647 25-Jan-12 08:00:07 105 1.7
End Snap: 650 25-Jan-12 11:00:08 99 1.7
Elapsed: 180.03 (mins)
DB Time: 110.06 (mins)


Load Profile Per Second Per Transaction Per Exec Per Call
~~~~~~~~~~~~ --------------- --------------- ---------- ----------
DB Time(s): 0.6 0.0 0.00 0.00
DB CPU(s): 0.2 0.0 0.00 0.00
Redo size: 247,952.4 1,567.3 <- Looks Okay but high / trasaction
Logical reads: 3,173.7 20.1
Block changes: 1,175.4 7.4
Physical reads: 0.9 0.0
Physical writes: 90.9 0.6
User calls: 549.9 3.5
Parses: 560.1 3.5
Hard parses: 0.0 0.0
W/A MB processed: 0.1 0.0
Logons: 3.3 0.0
Executes: 767.6 4.9
Rollbacks: 0.0 0.0
Transactions: 158.2

Top 5 Timed Foreground Events
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Avg
wait % DB
Event Waits Time(s) (ms) time Wait Class
------------------------------ ------------ ----------- ------ ------ ----------
DB CPU 2,157 32.7
log file sync 1,622,830 1,229 1 18.6 Commit <- 2nd highest?
virtual circuit wait 3,725,512 443 0 6.7 Network
gc current block 2-way 761,095 238 0 3.6 Cluster
SQL*Net more data to client 8,200,288 220 0 3.3 Network



select sid, event, time_waited, time_waited_micro
from v$session_event where sid=3 order by 3

SID EVENT TIME_WAITED TIME_WAITED_MICRO
---------- ----------------------------------- ----------- -----------------
3 gc current block congested 0 600
3 gc cr multi block request 0 787
3 db file scattered read 0 970
3 events in waitclass Other 0 496
3 gc cr grant 2-way 0 2879
3 gc current multi block request 0 928
3 enq: TX - row lock contention 1 6734
3 library cache pin 1 9755
3 gc cr block busy 1 6599
3 SQL*Net message to client 1 13261
3 enq: TM - contention 1 5227
3 library cache lock 1 5186
3 gc current grant 2-way 2 18169
3 gc current retry 2 20255
3 Disk file operations I/O 5 51449
3 enq: UL - contention 5 54879
3 db file sequential read 8 79643
3 gc current block busy 11 108024
3 row cache lock 15 150827
3 log file sync 68 683598 <- 5th highest actually
3 gc current grant busy 71 707643 <- This is why RAC is bad
3 gc cr block 2-way 72 717294 <- This is why RAC is bad
3 gc current block 2-way 94 941788 <- This is why RAC is bad
3 SQL*Net message from client 9395249 9.3952E+10

^LBackground Wait Events DB/Inst: STRAC01/strac011 Snaps: 647-650
-> ordered by wait time desc, waits desc (idle events last)
-> Only events with Total Wait Time (s) >= .001 are shown
-> %Timeouts: value of 0 indicates value was < .5%. Value of null is truly 0

Avg
%Time Total Wait wait Waits % bg
Event Waits -outs Time (s) (ms) /txn time
-------------------------- ------------ ----- ---------- ------- -------- ------
log file parallel write 1,754,414 0 642 0 1.0 35.7 <- redo is waiting on parallel writes and not switching
db file parallel write 36,158 0 122 3 0.0 6.8
Streams AQ: qmn coordinato 17 65 62 3642 0.0 3.4
gcs log flush sync 100,143 0 40 0 0.1 2.2
os thread startup 397 0 36 89 0.0 2.0


Regards,

Visu