Re: Substantial bloat in postgres_fdw regression test runtime

On Wed, Nov 2, 2016 at 10:09 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> In 9.6, "make installcheck" in contrib/postgres_fdw takes a shade
> under 3 seconds on my machine. In HEAD, it's taking 10 seconds.
> I am not happy, especially not since there's no parallelization
> of the contrib regression tests. That's a direct consumption of
> my time and all other developers' time too. This evidently came
> in with commit 7012b132d (Push down aggregates to remote servers),
> and while that's a laudable feature, I cannot help thinking that
> it does not deserve this much of an imposition on every make check
> that's ever done for the rest of eternity.
>

Thanks Tom for reporting this substantial bloat in postgres_fdw regression
test runtime. On my machine "make installcheck" in contrib/postgres_fdw
takes 6.2 seconds on master (HEAD:
770671062f130a830aa89100c9aa2d26f8d4bf32).
However if I remove all tests added for aggregate push down, it drops down
to 2.2 seconds. Oops 4 seconds more.

I have timed each of my tests added as part of aggregate push down patch and
observed that one of the test (LATERAL one) is taking around 3.5 seconds.
This is causing because of the parameterization. I have added a filter so
that we will have less number of rows for parameterization. Doing this,
lateral query in question now runs in 100ms. Also updated few more queries
which were taking more than 100ms to have runtime around 30ms or so. So
effectively, with changes "make installcheck" now takes around 2.5 seconds.

Attached patch with test-case modification.

Thanks

>
> regards, tom lane
>
>
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--
Jeevan B Chalke
Principal Software Engineer, Product Development
EnterpriseDB Corporation
The Enterprise PostgreSQL Company