Re: I/O EVENTS

In short:

Oracle is either using CPU or is waiting on a resource. If oracle is waiting on a resource, it could be an Oracle event (v$system_event/v$session_event), BUT what about waits that are not registered there ..... like
waiting for CPU, waiting for a memory page to be paged in ......

So just looking at v$system_event is dangerous. Looking v$system_event and v$sysstat is much better but still not perfect. The third way is ....... (mail me ;-))

Anjo.

S B wrote:

> Hi
>
> Can anybody explain the events like
> SQL*Net message from client,rdbms ipc message
> PX Idle Wait ,slave wait ...
>
> Can I assume a i/o bottleneck from the following
> statistics as most of the i/o events are having high
> wait time.
>
> select * from v$system_event
> order by TIME_WAITED;
>
> The last few entries are as follows.....
>
> EVENT TOTAL_WAITS
> TOTAL_TIMEOUTS TIME_WAITED AVERAGE_WAIT
> -----------------------------------------------------------------------------------
> SQL*Net more data to client 888137 0 12365
> 0.013922402
> db file parallel write 2445 0 17606
> 7.200818
> db file scattered read 7823 0 18336
> 2.34385786
> db file sequential read 27779 0 55490
> 1.99755211
> control file parallel write 27194 0 70593
> 2.59590351
> log file sync 29700 1 145295
> 4.89208754
> log file parallel write 30511 2 146311
> 4.7953525
> io done 35551 567 270796
> 7.61711344
> smon timer 278 273 8404285
> 30231.241
> pmon timer 27350 27349
> 8413237 307.613784
> SQL*Net message from client 498526 0 17655561
> 35.415527
> rdbms ipc message 112693 80775
> 33193981 294.552288
> PX Idle Wait 164145 164139
> 33650049 205.001974
> slave wait 433146 392872
> 40839651 94.2861091
>
> Regards
> Bhulu
>
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-- 
Author: Anjo Kolk
  INET: anjo_at_oraperf.com

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