Re: Make EXPLAIN generate a generic plan for a parameterized query

Christoph Berg <myon(at)debian(dot)org> writes:
> Re: Tom Lane
>> I don't actually see why a postgres_fdw test case is needed at all?
>> The tests in explain.sql seem sufficient.

> When I asked Laurenz about that he told me that local tables wouldn't
> exercise the code specific for EXEC_FLAG_EXPLAIN_GENERIC.

But there isn't any ... or at least, I fail to see what isn't sufficiently
exercised by that new explain.sql test case that's identical to this one
except for being a non-foreign table. Perhaps at some point this patch
modified postgres_fdw code? But it doesn't now.

I don't mind having a postgres_fdw test if there's something for it
to test, but it just looks duplicative to me. Other things being
equal, I'd prefer to test this feature in explain.sql, since (a) it's
a core feature and (b) the core tests are better parallelized than the
contrib tests, so the same test should be cheaper to run.

> (Admittedly my knowledge of the planner wasn't deep enough to verify
> that. Laurenz is currently traveling, so I don't know if he could
> answer this himself now.)

OK, thanks for the status update. What I'll do to get this off my
plate is to push the patch without the postgres_fdw test -- if
Laurenz wants to advocate for that when he returns, we can discuss it
more.

regards, tom lane