Re: [HACKERS] Duplicate object names in GRANT

Hi all,

I ran across this yesterday on HEAD:

template1=# grant select on foo, foo to swm;
ERROR: tuple already updated by self

We could do away with the error by producing a unique list of object names
-- but that would impose an extra cost on the common case. It seems to me
that producing a useful error message would entail the same cost, however.

Thoughts?

Gavin

Gavin Sherry <swm(at)linuxworld(dot)com(dot)au> writes:
> I ran across this yesterday on HEAD:

> template1=# grant select on foo, foo to swm;
> ERROR: tuple already updated by self

Seems to fail similarly in every version back to 7.2; probably further,
but that's all I have running at the moment.

> We could do away with the error by producing a unique list of object names
> -- but that would impose an extra cost on the common case.

CommandCounterIncrement in the GRANT loop would be easier, likely.
I'm having a hard time getting excited about it though...

regards, tom lane

On Wed, 27 Jul 2005, Tom Lane wrote:

> Gavin Sherry <swm(at)linuxworld(dot)com(dot)au> writes:
> > I ran across this yesterday on HEAD:
>
> > template1=# grant select on foo, foo to swm;
> > ERROR: tuple already updated by self
>
> Seems to fail similarly in every version back to 7.2; probably further,
> but that's all I have running at the moment.
>
> > We could do away with the error by producing a unique list of object names
> > -- but that would impose an extra cost on the common case.
>
> CommandCounterIncrement in the GRANT loop would be easier, likely.
> I'm having a hard time getting excited about it though...

Yeah, its not that exciting but that error message would throw your
average user.

I've attached a patch which calls CommandCounterIncrement() in each of the
grant loops.

Thanks,

Gavin

Patch applied. Thanks.

I also added a comment above each one to mention why it is needed.

---------------------------------------------------------------------------

Gavin Sherry wrote:
> On Wed, 27 Jul 2005, Tom Lane wrote:
>
> > Gavin Sherry <swm(at)linuxworld(dot)com(dot)au> writes:
> > > I ran across this yesterday on HEAD:
> >
> > > template1=# grant select on foo, foo to swm;
> > > ERROR: tuple already updated by self
> >
> > Seems to fail similarly in every version back to 7.2; probably further,
> > but that's all I have running at the moment.
> >
> > > We could do away with the error by producing a unique list of object names
> > > -- but that would impose an extra cost on the common case.
> >
> > CommandCounterIncrement in the GRANT loop would be easier, likely.
> > I'm having a hard time getting excited about it though...
>
> Yeah, its not that exciting but that error message would throw your
> average user.
>
> I've attached a patch which calls CommandCounterIncrement() in each of the
> grant loops.
>
> Thanks,
>
> Gavin

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