Re: [SQL] Re:Create table doesn't always respect atomicity of transactions

There's the same problem in v6.5 using temporary tables:

prova=> begin;
BEGIN
prova=> create temporary table prova(a text);
CREATE
prova=> insert into prova values('aa');
INSERT 225134 1
prova=> rollback;
ABORT
prova=> create table prova(a text);
ERROR: Relation 'prova' already exists
prova=> drop table prova;
ERROR: cannot find attribute 1 of relation pg_temp.17407.0
prova=>

Mark Dalphin ha scritto:

> Hi,
>
> Running version 6.4.2 of Postgresql on IRIX, I see exactly this same behavior,
> that is, when I create a table within a transaction and some later action in
> that transaction generates an error, leaving the transaction in an abort state,
> leaves me stuck with a ghost table. I can create a new table of the same name
> because "Table already exists" and I can't delete the table because that table
> "doesn't exist".
>
> I can, however, get around the problem by becoming the Postgres super-user and
> going into the data/base/...
> directory; there I find the file with the name of the ghost table (it is of size
> zero) and I delete it. The problem then goes away. I assume this bug arises
> from the order in which Postgres creates entries in its system tables and
> creates the file on the disk. As I am not creating tables on the fly, the bug
> only bites me when I am creating a new DB.
>
> In short, I can confirm the behavior you are seeing and I believe it occurs on
> multiple platforms. I can send in code to re-create the problem is people wish.
>
> Mark
>
> ----------------------
> Zalman Stern wrote:
>
> > Date: Mon, 21 Jun 1999 22:21:48 -0700 (PDT)
> > From: Zalman Stern
> > Subject: Create table doesn't always respect atomicity of transactions.
> >
> > Off and on, I've been seeing a situation where the following code:
> > begin;
> > create table foo (name text);
> > abort; leaves a file called "foo" in the database directory and
> > further attempts to create a relation called foo or to select anything from
> > it all fail. The database has been left in an inconsistent state.
> >
> > I filed a bug report on this earlier today as it seemed dead on repeatable.
> > But then I recompiled with debug symbols to have a go at figuring out what
> > was up and the problem went away. So I recompiled with full optimization
> > again and the problem still doesn't occur now. I've been starting over each
> > time with a fresh database so if it was some property of the database
> > itself, then that state is lost. But this is not the first time I've seen
> > this. Has any one else seen such a thing? Its rather troublesome 'cause when
> > it does happen, the database is somewhat unuseable until I remove the file
> > in question and I hate going in and removing files that are supposed to be
> > under Postgres' control...
> >
> >
> --
> Mark Dalphin email: mdalphin(at)amgen(dot)com
> Mail Stop: 29-2-A phone: +1-805-447-4951 (work)
> One Amgen Center Drive +1-805-375-0680 (home)
> Thousand Oaks, CA 91320 fax: +1-805-499-9955 (work)

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PostgreSQL 6.5.0 on i586-pc-linux-gnu, compiled by gcc 2.7.2.3
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Jose'