Re: log file sync + latch free WAITs

From: Vitaliy Mogilevskiy <vit100gain_at_hotmail.com>
Date: Tue, 30 Jan 2001 21:22:36 GMT
Message-ID: <3A773131.BE067895@hotmail.com>

Thanks,

Oracle8i Enterprise Edition Release 8.1.6.0.0 - Production IBM/AIX RISC System/6000

David Fitzjarrell wrote:

> 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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Received on Tue Jan 30 2001 - 15:22:36 CST