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: 2017-09-21T12:21:30Z
Lists: pgsql-hackers

Attachments

On Thu, Sep 21, 2017 at 9:12 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Tue, Sep 19, 2017 at 5:47 AM, Ashutosh Bapat
> <ashutosh.bapat@enterprisedb.com> wrote:
>> Done.
>
> Committed 0001 with extensive editorialization.  I did not think it
> was a good idea to include a partition.h a file in src/include/nodes,
> so I worked around that.  The include of pg_inherits_fn.h was
> unneeded.  I rewrote a lot of the comments and made some other style
> tweaks.

Thanks a lot Robert. Thanks for changing comments to be more precise and crisp.

Here's set of rebased patches. The patch with extra tests is not for
committing. All other patches, except the last one, will need to be
committed together. The last patch may be committed along with other
patches or as a separate patch.

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.

-- 
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.