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: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, Robert Haas <robertmhaas@gmail.com>
Cc: Thomas Munro <thomas.munro@enterprisedb.com>, Rafia Sabih <rafia.sabih@enterprisedb.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-09-04T03:38:55Z
Lists: pgsql-hackers 
On 2017/09/02 4:10, Ashutosh Bapat wrote:
> This rebase mainly changes patch 0001, which translates partition
> hierarchy into inheritance hierarchy creating AppendRelInfos and
> RelOptInfos for partitioned partitions. Because of that, it's not
> necessary to record the partitioned partitions in a
> PartitionedChildRelInfos::child_rels. The only RTI that goes in there
> is the RTI of child RTE which is same as the parent RTE except inh
> flag. I tried removing that with a series of changes but it seems that
> following code in ExecInitModifyTable() requires it.
> 1897     /* The root table RT index is at the head of the
> partitioned_rels list */
> 1898     if (node->partitioned_rels)
> 1899     {
> 1900         Index       root_rti;
> 1901         Oid         root_oid;
> 1902
> 1903         root_rti = linitial_int(node->partitioned_rels);
> 1904         root_oid = getrelid(root_rti, estate->es_range_table);
> 1905         rel = heap_open(root_oid, NoLock);  /* locked by InitPlan */
> 1906     }
> 1907     else
> 1908         rel = mtstate->resultRelInfo->ri_RelationDesc;
> 
> I don't know whether we could change this code not to use
> PartitionedChildRelInfos::child_rels.
Though I haven't read the patch yet, I think the above code is useless. 
And I proposed a patch to clean it up before [1].  I'll add that patch 
to the next commitfest.

Best regards,
Etsuro Fujita

[1] 
https://www.postgresql.org/message-id/93cf9816-2f7d-0f67-8ed2-4a4e497a6ab8%40lab.ntt.co.jp

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.