Horton

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

Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>

View thread View on postgr.es
From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: 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>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-10-05T09:38:08Z
Lists: pgsql-hackers 
On Wed, Oct 4, 2017 at 9:01 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Thu, Sep 21, 2017 at 8:52 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>> On Thu, Sep 21, 2017 at 8:21 AM, Ashutosh Bapat
>> <ashutosh.bapat@enterprisedb.com> wrote:
>>> About your earlier comment of making build_joinrel_partition_info()
>>> simpler. Right now, the code assumes that partexprs or
>>> nullable_partexpr can be NULL when either of them is not populated.
>>> That may be saves a sizeof(pointer) * (number of keys) byes of memory.
>>> Saving that much memory may not be worth the complexity of code. So,
>>> we may always allocate memory for those arrays and fill it with NIL
>>> values when there are no key expressions to populate those. That will
>>> simplify the code. I haven't done that change in this patchset. I was
>>> busy debugging the Q7 regression. Let me know your comments about
>>> that.
>>
>> Hmm, I'm not sure that's the best approach, but let me look at it more
>> carefully before I express a firm opinion.
>
> Having studied this a bit more, I now think your proposed approach is
> a good idea.

Thanks. Done.

-- 
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.