Re: pgpool versus sequences

On Wed, Jun 1, 2011 at 6:04 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> I wrote:
>>>>> I think the most appropriate solution may be to disallow SELECT FOR
>>>>> UPDATE/SHARE on sequences ... so if you have a good reason why we
>>>>> shouldn't do so, please explain it.
>
> Attached is a proposed patch to close off this hole.  I found that
> somebody had already inserted code to forbid the case for foreign
> tables, so I just extended that idea a bit (by copying-and-pasting
> CheckValidResultRel).  Questions:
>
> * Does anyone want to bikeshed on the wording of the error messages?

Not particularly.

> * Does anyone want to argue for not forbidding SELECT FOR UPDATE on
>  toast tables?

Maybe. How hard would it be to fix that so it doesn't blow up? What
I don't like about the proposed solution is that it will cause very
user-visible breakage as a result of a minor release upgrade, for
anyone using pgpool, which is a lot of people; unless pgpool is
upgraded to a sufficiently new version first.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company