Re: minor fix for acquire_inherited_sample_rows

On Thu, Apr 26, 2018 at 7:08 PM, Amit Langote <amitlangote09(at)gmail(dot)com> wrote:
> On Thu, Apr 26, 2018 at 9:54 PM, Ashutosh Bapat
> <ashutosh(dot)bapat(at)enterprisedb(dot)com> wrote:
>> On Thu, Apr 26, 2018 at 1:08 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>>> +1. I think we're really abusing equalTupleDescs() for purposes for
>>> which it was not invented. Instead of changing it, let's invent a new
>>> function that tests for the thing partitioning cares about (same
>>> ordering of the same columns with the same type information) and call
>>> it logicallyEqualTupleDescs() or something like that.
>>
>> Why don't we just rely on the output of convert_tuples_by_name(),
>> which it seems is always called right now? What's advantage of adding
>> another tuple descriptor comparison?
>
> The patch I mentioned in my email above does more or less that (what
> you're saying we should do). In fact it even modifies
> convert_tuple_by_name and convert_tuple_by_name_map to remove some
> redundant computation. See that patch here if you're interested:
>
> https://www.postgresql.org/message-id/825031be-942c-8c24-6163-13c27f217a3d%40lab.ntt.co.jp

I spent some time looking at the patch. The patch clubs all kinds of
refactoring together, making review a bit difficult. I think, it would
be better to split the patch into multiple, each addressing one set of
changes, it might become easier to review.

--
Best Wishes,
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database Company