Horton

Re: [HACKERS] Partition-wise join for join between (declaratively) partitioned tables

Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>

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From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
To: Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>, Thomas Munro <thomas.munro@enterprisedb.com>, Rafia Sabih <rafia.sabih@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2018-02-07T08:30:32Z
Lists: pgsql-hackers 
On Fri, Dec 22, 2017 at 3:00 PM, Rajkumar Raghuwanshi
<rajkumar.raghuwanshi@enterprisedb.com> wrote:
> On Wed, Dec 20, 2017 at 5:21 PM, Ashutosh Bapat
> <ashutosh.bapat@enterprisedb.com> wrote:
>>
>> Thanks. Here are some comments
>>
> Thanks Ashutosh for review and suggestions.
>
>>
>> +-- test default partition behavior for range
>> +ALTER TABLE prt1 DETACH PARTITION prt1_p3;
>> +ALTER TABLE prt1 ATTACH PARTITION prt1_p3 DEFAULT;
>> +ALTER TABLE prt2 DETACH PARTITION prt2_p3;
>> +ALTER TABLE prt2 ATTACH PARTITION prt2_p3 DEFAULT;
>>
>> I think we need an ANALYZE here in case the statistics gets updated while
>> DETACH and ATTACH is going on. Other testcases also need to be updated
>> with
>> ANALYZE, including the negative one.
>
> Done.
>
>>
>>
>> +-- partition-wise join can not be applied if the only one of joining
>> table have
>>
>> Correction: ... if only one of the joining tables has ...
>
> Done.
>
>>
>> Please add the patch to the next commitfest so that it's not
>> forgotten.
>
> Done.
> Added to CF: https://commitfest.postgresql.org/16/1426/
>
>>
>> I think we can get rid of the multi-level partition-wise
>> testcase as well. Also, since we are re-attaching existing partition
>> tables as default partitions, we don't need to check the output as
>> well; just plan should be enough.
>
> Ok. Done.
>
> updated test patch attached.
>

The patch looks good to me. I don't think we can reduce it further.
But we need some tests to test PWJ with default partitions. Marking
this as ready for committer.

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

Commits

  1. Add test for partitionwise join involving default partition.

  2. Rewrite the code that applies scan/join targets to paths.

  3. Fix code related to partitioning schemes for dropped columns.

  4. Copy information from the relcache instead of pointing to it.

  5. Basic partition-wise join functionality.

  6. Associate partitioning information with each RelOptInfo.

  7. Expand partitioned table RTEs level by level, without flattening.

  8. Set partitioned_rels appropriately when UNION ALL is used.

  9. Remove dedicated B-tree root-split record types.

  10. Assorted preparatory refactoring for partition-wise join.

  11. Teach adjust_appendrel_attrs(_multilevel) to do multiple translations.

  12. Avoid unnecessary single-child Append nodes.

  13. Revisit handling of UNION ALL subqueries with non-Var output columns.