Re: [COMMITTERS] pgsql: Only try to push down foreign joins if the user mapping OIDs mat

On Fri, Mar 11, 2016 at 10:15 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:
> On 2016-01-28 19:09:01 +0000, Robert Haas wrote:
>> Only try to push down foreign joins if the user mapping OIDs match.
>>
>> Previously, the foreign join pushdown infrastructure left the question
>> of security entirely up to individual FDWs, but it would be easy for
>> a foreign data wrapper to inadvertently open up subtle security holes
>> that way. So, make it the core code's job to determine which user
>> mapping OID is relevant, and don't attempt join pushdown unless it's
>> the same for all relevant relations.
>>
>> Per a suggestion from Tom Lane. Shigeru Hanada and Ashutosh Bapat,
>> reviewed by Etsuro Fujita and KaiGai Kohei, with some further
>> changes by me.
>
> I noticed that this breaks some citus regression tests in a minor
> manner. Namely previously file_fdw worked without a user mapping, now it
> doesn't appear to anymore.
>
> This is easy enough to fix, and it's perfectly ok for us to fix this,
> but I do wonder if that's not going to cause trouble for others.

Hmm, I didn't intend to change that. If that commit broke something,
there's obviously a hole in our regression test coverage.

--
Robert Haas
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