Re: 8.3.0 backend segfaults

Alex Hunsaker wrote:
> Precedence: bulk
> Sender: pgsql-bugs-owner@postgresql.org
>
> On Wed, Mar 12, 2008 at 9:49 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
>> "Alex Hunsaker" <badalex@gmail.com> writes:
>>  > On Wed, Mar 12, 2008 at 12:44 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>
>>
>>>> If you say "none of my stuff is changing any schemas", then I'd guess
>>>>
>>  >> that the triggering event is a background autovacuum, which forces
>>  >> replan just like an intentional schema change would.  Does stopping
>>  >> autovacuum make the problem go away?
>>
>>  > Yep turning off autovacuum seems to have fixed it.  And once I
>>  > manually vacuum analyze workers; it blows up almost instantly.
>>
>>  Yeah, I was going to suggest that you ought to be able to extract
>>  a test case involving doing a manual vacuum in between prepare and
>>  execute.  I suspect it wouldn't even need to involve more than one
>>  session.
>>
>
> Here is what im trying right now with no success:
>
> 3 clients doing this:
> while(1)
> {
>         $db->begin_work();
>         my $sth = $db->prepare_cached('select * from junk left join
> junk as j on j.junk = junk.junk where junk.junk like ? limit 1;');
>         print "VAC!\n";
>         sleep 10;
>         print "EX!\n";
>         $sth->execute('junk') || die "failed: $!";
>         $sth->fetchall_arrayref();
>         $db->commit();
>         $db->{'AutoCommit'} = 0;
>         $db->{'AutoCommit'} = 1;
> }
>
> where when it prints VAC I :
> update junk set junk = 'junkab';
> VACUUM ANALYZE verbose junk;
> (also tried deleting, and inserting a bunch of junk...)
>
> 3 other clients doing:
> while(1)
> {
>         $db->begin_work();
>         my $sth = $db->prepare_cached('select * from junk left join
> junk as j on j.junk = junk.junk where junk.junk like ? limit 1;');
>         $sth->execute('junk') || die "failed: $!";
>         $sth->fetchall_arrayref();
>         $db->rollback();
> }
>
> \d junk
>     Table "public.junk"
>  Column | Type | Modifiers
> --------+------+-----------
>  junk   | text |
>
>
Hola, esto (like ? ) generalmente no funciona en un prepared statement,
quizas tu problema este ahi.
proba con un =? , (se que no es lo mismo) y si funciona el problema es
el like

Saludos Fernando