Re: log file sync + latch free WAITs

In our last gripping episode Vitaliy Mogilevskiy <vit100gain_at_hotmail.com> wrote:
> I got a problem where a session WAIT's for "log file sync" + "latch
> free" forever and REDO LOGS never get switched. If I manually switch
> the logs (ALTER SYSTEM SWITCH LOGFILE) the "switch" succeeds but it
> doesn't help the session WAITs.
>
> V$SESSION_WAIT (waits are either "latch free" or "log file sync"
> ================================================================
> EVENT P1TEXT P1
> ------------------------- ------------------------- ---------
> log file sync buffer# 38
>
> EVENT P1TEXT P1
> ------------------------- ------------------------- ---------
> latch free address 805363076
>
> When "log file sync" waits occur P1 increments by 1 with intervals of
> 3-5 seconds then eventually "latch free" wait occurs (P1 for "latch
> free" is always same = 805363076). Below is the summary for
> waits/timeouts.
>
> V$SESSION_EVENT
> ==================================================
> SQL> /
>
> SID EVENT TOTAL_WAITS
 TOTAL_TIMEOUTS
>
> --------- ----------------------------------- ----------- ------------
 --
>
> 23 latch free 1618
 957
>
> 23 process startup

 4 0
>
> 23 rdbms ipc reply

 29 0
>
> 23 enqueue

 18 0
>
> 23 free buffer waits

 14 0
>
> 23 local write wait

 3 0
>
> 23 log buffer space

 568 0
>
> 23 log file switch completion 259
 27
>
> 23 log file sync 116801
 212
>
> 23 db file sequential read

 355 0
>
> 23 db file scattered read

 396 0
>
> 23 file open

 6 0
>
> 23 SQL*Net message to client

 87 0
>
> 23 SQL*Net message from client

 87 0
>
> 23 PX Deq: Join ACK

 27 0
>
> 23 PX Deq: Signal ACK 27
 12
>
> 23 PX Deq: Parse Reply

 17 0
>
> 23 PX Deq: Execute Reply

 1401 0
>
> 18 rows selected.
>
> Please help guys! Never seen this before.
>
>

Oracle release, O/S vendor and release information please.

--
David Fitzjarrell
Oracle Certified DBA


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