Horton

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

Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>

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From: Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>
To: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Cc: Robert Haas <robertmhaas@gmail.com>, 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: 2017-09-05T06:35:20Z
Lists: pgsql-hackers 
On 2017/09/05 13:20, Amit Langote wrote:
> On 2017/09/04 21:32, Ashutosh Bapat wrote:

>> +1. Will Fujita-san's patch also handle getting rid of partitioned_rels list?
> 
> As Fujita-san mentioned, his patch won't.  Actually, I suppose he didn't
> say that partitioned_rels itself is useless, just that its particular
> usage in ExecInitModifyTable is.

That's right.  (I thought there would probably be no need to create that 
list if we created AppendRelInfos even for partitioned partitions.)

> We still need that list for planner to
> tell the executor that there are some RT entries the latter would need to
> lock before executing a given plan.  Without that dedicated list, the
> executor cannot know at all that certain tables in the partition tree
> (viz. the partitioned ones) need to be locked.  I mentioned the reason -
> (Merge)Append.subplans, ModifyTable.resultRelations does not contain
> respective entries corresponding to the partitioned tables, and
> traditionally, the executor looks at those lists to figure out the tables
> to lock.

I think so too.

Best regards,
Etsuro Fujita

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.