Re: [HACKERS] [PATCH] Push limit to sort through a subquery

Robert Haas <robertmhaas@gmail.com> writes:
> On Fri, Aug 25, 2017 at 2:01 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> I looked through this a little, and feel uncomfortable with the division
>> of typedefs between execnodes.h and tuplesort.h.  I'm inclined to push
>> struct SortInstrumentation, and maybe also SharedSortInfo, into
>> tuplesort.h.

> I think moving SharedSortInfo into tuplesort.h would be a gross
> abstraction violation, but moving SortInstrumentation into tuplesort.h
> seems like a modest improvement.

Hmm, I'm not sure why SortInstrumentation belongs naturally to
tuplesort.h but putting an array of them there would be a "gross
abstraction violation".  Perhaps it would help to rename
struct SharedSortInfo to SortInstrumentationArray, and change its
field names to be less specific to the parallel-worker use case?

>> (BTW, would it make sense to number the workers from 1 not 0 in the
>> EXPLAIN printout?)

> ... So I'm in favor of leaving it alone; I don't think that 0-based
> indexing is such an obscure convention that it will flummox users.

OK, I'm not particularly set on that.
        regards, tom lane