Re: deadlock trace interpretation

From: Ted Chyn <tedchyn_at_yahoo.com>
Date: 7 Oct 2002 09:25:59 -0700
Message-ID: <44a19320.0210070825.5a48b18c@posting.google.com>

jonathan, thanks for the reply. the plateform deadlock occurs is 64 bits HP UX and 64 bits oracle 8.1.7.4.
Can you shed more light on following questions ?

2. how to translate object handle (c000000020a80868),

                     waiting session(c0000000044de890),
                    block session(c000000006f10a70)

  to object_id or object name and more meaningful session number ?

regards

"Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message news:<ann6di$8q5$1$8302bc10_at_news.demon.co.uk>...
> I was going to send you a simple example of making this happen,
> but I just tested it on 9.2 and got an even funnier result.
>
> create or replace proc_a as
> begin
> dbms_lock.sleep(10);
> execute immediate 'alter proc_b compile';
> end;
> /
>
> create or replace proc_b as
> begin
> dbms_lock.sleep(10);
> execute immediate 'alter proc_a compile';
> end;
> /
>
> Then from session 1 issue
> execute proc_a
> and from session 2
> execute proc_b
>
> I was expecting a 3-second deadlock - but got a 5 minute
> timeout with error message 4021: but you get the idea.
> Whilst the wait was going on, v$session_wait showed
> 'library cache pin'.
>
>
>
> There are various (usually buggy) things that cause
> objects to become invalid and require revalidation.
>
> But it is possible for a session to be executing some
> code which is pinning an object in share mode, and
> since the recompile needs a pin in exclusive mode
> you get a wait - once you get a wait, you can usually
> engineer a deadlock.
>
> The waiting/blocking sessions are probably the addr
> value from V$session. (Looks like you have a 64bit
> platform). The object handle is one of the raw columns
> from (I think) v$db_object_cache - possible something
> like kglhdpar.
>
> --
> Regards
>
> Jonathan Lewis
> http://www.jlcomp.demon.co.uk
>
> Next Seminar dates:
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>
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>
>
>
>
>
> Ted Chyn wrote in message
> <44a19320.0210040923.52b02e78_at_posting.google.com>...
> >all:
> >I have follwing deadlock trace file.
> >
> >my question:
> >1. what is ddl and parse locks ?
> >
> >2. how to translate object handle (c000000020a80868),
> > waiting session(c0000000044de890),
> > block session(c000000006f10a70)
> > to object_id or object name and more meaningful session number ?
> >
> >
> >thnx in advance
> >ted chyn
Received on Mon Oct 07 2002 - 11:25:59 CDT