From: | Dmitry Dolgov <9erthalion6(at)gmail(dot)com> |
---|---|
To: | Ashutosh Bapat <ashutosh(dot)bapat(at)enterprisedb(dot)com> |
Cc: | Robert Haas <robertmhaas(at)gmail(dot)com>, Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp>, Antonin Houska <ah(at)cybertec(dot)at>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: [HACKERS] advanced partition matching algorithm for partition-wise join |
Date: | 2018-08-30 08:53:32 |
Message-ID: | CA+q6zcXvCg8_a_-qc+w_o4fe2kkpKFHzVyU5_8+DLzL2pBOdCg@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
> On Wed, 29 Aug 2018 at 09:32, Ashutosh Bapat <ashutosh(dot)bapat(at)enterprisedb(dot)com> wrote:
>
> > * Many functions carry some unrelated arguments just to pass them through,
> > which obscures the purpose of a function.
>
> Can you please provide some examples?
E.g this chain with partsupfunc & collations:
partition_range_bounds_merge
-> partition_range_cmp
-> partition_range_bound_cmp
-> partition_range_merge_next_lb
I believe I already mentioned that before (although I'm not saying that I have
a solution right away, it just bothers me).
> > * I want to suggest to introduce a new data structure for partitions mapping
> > instead of just keeping them in arrays (was it discussed already before?).
>
> The best I could think of was a structure with just two arrays. So,
> instead of encapsulating the arrays within a structure, I thought it
> best to pass bare arrays around. If you have any other ideas, please
> let me know.
Well, what I had in mind is something like a structure Mapping with fields from
& to.
> > * What is the reason that almost everywhere in the patch there is a naming
> > convention "outer/inner" partition maps, and sometimes (e.g. in
> > generate_matching_part_pairs) it's "map1/map2"?
>
> You will find that the optimizer in general uses outer/inner,
> rel1/rel2 nomenclature interchangeably. This patch-set just inherits
> that. But yes, we should do more to straighten it out.
Thanks, good to know.
> I won't be working on this actively in the next commitfest. I will be
> glad if somebody else wants to take this up. If there's nobody,
> probably we should mark this entry as "returned with feedback" in the
> next commitfest.
Since I'm more or less familiar with the code and I believe it's an interesting
feature, I can try to take over it for now if you don't mind (but without any
strong commitments to make it perfectly shining for the next CF).
From | Date | Subject | |
---|---|---|---|
Next Message | Michael Banck | 2018-08-30 08:54:08 | Re: pg_verify_checksums -d option (was: Re: pg_verify_checksums -r option) |
Previous Message | Yugo Nagata | 2018-08-30 08:48:24 | Re: pg_verify_checksums -d option (was: Re: pg_verify_checksums -r option) |