Re: pgsql: Add parallel-aware hash joins.

Thomas Munro <thomas(dot)munro(at)enterprisedb(dot)com> writes:
> On Thu, Dec 28, 2017 at 3:32 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Aside from the instability problems, I'm pretty unhappy about how much
>> the PHJ patch has added to the runtime of "make check". I do not think
>> any one feature can justify adding 20% to that. Can't you cut down the
>> amount of data processed by these new test cases?

> Isn't that mostly because of the CV livelock problem?

Hm, maybe. I quoted the 20% figure on the basis of longfin's reports,
not prairiedog's ... but it might be seeing some of the livelock effect
too.

> So without the effects of that bug it's only taking 2.4% longer than
> commit fa330f9a. Is that acceptable for a feature of this size and
> complexity? I will also look into making the data sets smaller.

That sounds better, but it's still worth asking whether the tests
could be quicker.

regards, tom lane