Horton

Re: partition routing layering in nodeModifyTable.c

Amit Langote <amitlangote09@gmail.com>

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From: Amit Langote <amitlangote09@gmail.com>
To: Alvaro Herrera <alvherre@alvh.no-ip.org>
Cc: Heikki Linnakangas <hlinnaka@iki.fi>, Daniel Gustafsson <daniel@yesql.se>, Etsuro Fujita <etsuro.fujita@gmail.com>, Andres Freund <andres@anarazel.de>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2020-10-19T04:54:27Z
Lists: pgsql-hackers

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On Sun, Oct 18, 2020 at 12:54 AM Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> On 2020-Oct-17, Amit Langote wrote:
> > Hmm, I don't see ri_PartitionCheckExpr as being a piece of routing
> > information, because it's primarily meant to be used when inserting
> > *directly* into a partition, although it's true we do initialize it in
> > routing target partitions too in some cases.
> >
> > Also, ChildToRootMap was introduced by the trigger transition table
> > project, not tuple routing.  I think we misjudged this when we added
> > PartitionToRootMap to PartitionRoutingInfo, because it doesn't really
> > belong there.  This patch fixes that by removing PartitionToRootMap.
> >
> > RootToPartitionMap and the associated partition slot is the only piece
> > of extra information that is needed by tuple routing target relations.
>
> Well, I was thinking on making the ri_PartitionInfo be about
> partitioning in general, not just specifically for partition tuple
> routing.  Maybe Heikki is right that it may end up being simpler to
> remove ri_PartitionInfo altogether.  It'd just be a couple of additional
> pointers in ResultRelInfo after all.

So that's 2 votes for removing PartitionRoutingInfo from the tree.
Okay, I have tried that in the attached 0002 patch.  Also, I fixed
some comments in 0001 that still referenced PartitionToRootMap.

-- 
Amit Langote
EDB: http://www.enterprisedb.com

Commits

  1. Fix initialization of es_result_relations in EvalPlanQualStart().

  2. Remove PartitionRoutingInfo struct.

  3. Revise child-to-root tuple conversion map management.

  4. Clean up code to resolve the "root target relation" in nodeModifyTable.c

  5. Refactor code for cross-partition updates to a separate function.

  6. Remove es_result_relation_info from EState.

  7. Include result relation info in direct modify ForeignScan nodes.

  8. Create ResultRelInfos later in InitPlan, index them by RT index.