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From: Emmanuel Cecchet <manu@frogthinker.org>
To: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@postgresql.org
Subject: Re: Transactions and temp tables
Date: Mon, 01 Dec 2008 15:50:42 -0500
Message-ID: <49344E22.2000008@frogthinker.org> (raw)
In-Reply-To: <492B377F.4080602@frogthinker.org>
References: <48EA7B12.6050906@frogthinker.org>
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	<492B377F.4080602@frogthinker.org>

Heikki,

I think that the Assert in is_temp_rel(Oid) in tablecmds.c should be 
replaced by if (on_commits == NULL) return false;
As the use case below shows, a regular table can be created and hold a 
LOCKTAG_RELATION lock that will trigger the call to is_temp_rel in 
is_preparable_locktag. The assert will break if no temp table was accessed.

As we were also trying to list potential issues, if the temp table uses 
a SERIAL type, will there be potentially a problem with the sequence at 
prepare time?

Emmanuel


> The following test fails with your patch on my system. Could you check 
> if you can reproduce?
>
> psql (8.4devel)
> Type "help" for help.
>
> test=# begin;
> BEGIN
> test=# create table paul(x int);
> CREATE TABLE
> test=# insert into paul values(1);
> INSERT 0 1
> test=# prepare transaction 'persistentTableShouldSucceed';
> server closed the connection unexpectedly
>        This probably means the server terminated abnormally
>        before or while processing the request.
> The connection to the server was lost. Attempting reset: Failed.
>
> ---
>
> LOG:  database system is ready to accept connections
> TRAP: FailedAssertion("!(on_commits != ((void *)0))", File: 
> "tablecmds.c", Line: 7823)
> LOG:  server process (PID 15969) was terminated by signal 6: Aborted
> LOG:  terminating any other active server processes
> FATAL:  the database system is in recovery mode
>
>
> Thanks,
> manu
>


-- 
Emmanuel Cecchet
FTO @ Frog Thinker 
Open Source Development & Consulting
--
Web: http://www.frogthinker.org
email: manu@frogthinker.org
Skype: emmanuel_cecchet




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