Re: advanced partition matching algorithm for partition-wise join

Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>

From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>

To: Antonin Houska <ah@cybertec.at>

Cc: pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2017-09-11T08:08:21Z

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 →

Suppress unused-variable warning.
- 401418ca6a68 13.0 landed
Allow partitionwise joins in more cases.
- c8434d64ce03 13.0 landed
Avoid crash in partitionwise join planning under GEQO.
- 7ad6498fd5a6 12.0 cited
- d70c147fa217 11.3 cited
Disable support for partitionwise joins in problematic cases.
- 7cfdc77023ad 12.0 cited
Add plan_cache_mode setting
- f7cb2842bf47 12.0 cited
Add test for partitionwise join involving default partition.
- 4513d3a4be0b 12.0 cited
Revise API for partition_rbound_cmp/partition_rbound_datum_cmp.
- b0229235564f 11.0 landed

On Thu, Sep 7, 2017 at 7:34 PM, Antonin Houska <ah@cybertec.at> wrote:
> Ashutosh Bapat <ashutosh.bapat@enterprisedb.com> wrote:
>
>> I have fixed the issues which were marked as TODOs in the attached
>> patches. Also, I have included your test change patch in my series of
>> patches.
>
> I've noticed that partition_bounds_merge() is called twice from
> make_join_rel():
>
>  * build_join_rel -> build_joinrel_partition_info -> partition_bounds_merge
>
>  * try_partition_wise_join -> partition_bounds_merge
>
> Is this intentional, or just a thinko?
>

This is expected. partition_bounds_merge() also returns the pairs of
matching partitions. So, we have to call that function for every pair
of joining relations.

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