Re: Missing CHECK_FOR_INTERRUPTS in hash joins

Thomas Munro <thomas(dot)munro(at)enterprisedb(dot)com> writes:
> On Wed, Feb 15, 2017 at 2:22 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Adding a C.F.I. inside this loop is the most straightforward fix, but
>> I am leaning towards adding one in ExecHashJoinGetSavedTuple instead,

> Would it also make sense to put one in the loop in
> ExecHashIncreaseNumBatches (or perhaps
> ExecHashJoinSaveTuple for symmetry with the above)? Otherwise you
> might have to wait for a few hundred MB of tuples to be written out
> which could be slow if IO is somehow overloaded.

Mmm, good point. I think in that case the C.F.I. had better be in
the loop in ExecHashIncreaseNumBatches, because if you were unlucky
the loop might not take the ExecHashJoinSaveTuple path for a long time.

Looking around at other callers of ExecHashJoinSaveTuple, the only one
that seems to be in need of a C.F.I. is the loop in
ExecHashRemoveNextSkewBucket, and there again there's a code path
whereby the loop doesn't call ExecHashJoinSaveTuple.

Will CFI-ify all three places.

regards, tom lane