Horton

Re: [HACKERS] advanced partition matching algorithm for partition-wise join

amul sul <sulamul@gmail.com>

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From: amul sul <sulamul@gmail.com>
To: Etsuro Fujita <etsuro.fujita@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Thomas Munro <thomas.munro@gmail.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>, Dmitry Dolgov <9erthalion6@gmail.com>, Antonin Houska <ah@cybertec.at>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2019-11-06T06:11:47Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Suppress unused-variable warning.

  2. Allow partitionwise joins in more cases.

  3. Avoid crash in partitionwise join planning under GEQO.

  4. Disable support for partitionwise joins in problematic cases.

  5. Add plan_cache_mode setting

  6. Add test for partitionwise join involving default partition.

  7. Revise API for partition_rbound_cmp/partition_rbound_datum_cmp.

Attachments

Attached is the rebase atop the latest master head(a9056cc637f).

On Tue, Nov 5, 2019 at 6:44 PM amul sul <sulamul@gmail.com> wrote:

>
>
> On Fri, Nov 1, 2019 at 3:58 PM Etsuro Fujita <etsuro.fujita@gmail.com>
> wrote:
>
>> On Thu, Oct 31, 2019 at 6:49 PM Etsuro Fujita <etsuro.fujita@gmail.com>
>> wrote:
>> > Attached is an updated version.  If no objections, I'll merge this
>> > with the main patch [1].
>>
>> Done.  Attached is a new version of the patch.
>>
>> Other changes: in generate_matching_part_pairs(), I changed variable
>> names to match other functions, simplified assertions, and
>> adjusted/added comments a bit.
>>
>
> Thanks for the update version.
>
> A query and comments for v25:
>
> 583 + * The function returns NULL if we can not find the matching pair of
>  584 + * partitions. This happens if 1. multiple partitions on one side
> match with
>  585 + * one partition on the other side. 2. a given partition on the
> outer side
>  586 + * doesn't have a matching partition on the inner side. We can not
> support the
>  587 + * first case since we don't have a way to represent multiple
> partitions as a
>  588 + * single relation (RelOptInfo) and then perform join using the
> ganged
>  589 + * relation. We can not support the second case since the missing
> inner
>  590 + * partition needs to be represented as an empty relation and we
> don't have a
>  591 + * way to introduce empty relation during join planning after
> creating paths
>  592 + * for all the base relations.
>  593 + */
>  594 +PartitionBoundInfo
>  595 +partition_bounds_merge(int partnatts,
>
> I think the second condition mention for partition_bounds_merge() looks
> outdated, do you think we should remove that or am I missing something
> here?
> ---
>
> 1768 +
> 1769 +       /*
> 1770 +        * If this is an outer join, the merged partition would act
> as the
> 1771 +        * default partition of the join; record the index in
> *default_index
> 1772 +        * if not done yet.
> 1773 +        */
> 1774 +       if (jointype == JOIN_LEFT || jointype == JOIN_ANTI ||
> 1775 +           jointype == JOIN_FULL)
> 1776 +       {
>
> As decided need to replace this list by IS_OUTER_JOIN(jointype).
> ---
>
> 2020 +       if (jointype == JOIN_LEFT || jointype == JOIN_FULL ||
> 2021 +           jointype == JOIN_ANTI)
> 2022 +       {
>
> Same as the previous.
> ---
>
> I tried a coverage testing and tried to adjust & add a few tests to
> improved the
> code coverage for the v25 patch. Please have a look at the attached 0002 &
> also
> attach the coverage output with & without this patch, TWIMW.
>
> 0001 is the same v25 patch, reattaching to make CFbot happy.
>
> Regards,
> Amul
>
>