Re: Optimization for updating foreign tables in Postgres FDW

On Fri, Apr 8, 2016 at 6:28 PM, Robert Haas <robertmhaas@gmail.com> wrote:

On Fri, Apr 8, 2016 at 3:05 AM, Etsuro Fujita
<fujita.etsuro@lab.ntt.co.jp> wrote:
>> What do you think?  This open item's seven-day deadline has passed.  It
>> would
>> help keep things moving to know whether you consider your latest patch
>> optimal
>> or whether you wish to change it the way Michael described.
>
> I wish to change it that way because it not only avoids the duplicate but
> fixes a bug in the previous patch that I overlooked that there is a race
> condition if a signal arrives just before entering the CheckSocket.
>
> Attached is an updated version of the patch.

The comment just before the second hunk in the patch says:

       * We don't use a PG_TRY block here, so be careful not to throw error
       * without releasing the PGresult.

But the patch adds a whole bunch of new things there that seem like
they can error out, like CHECK_FOR_INTERRUPTS(), for example.  Isn't
that a problem?

Basically we fetching the PGresult, after the newly added hunk, so there

 

--
Robert Haas
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