Horton

Re: speeding up planning with partitions

Amit Langote <langote_amit_f8@lab.ntt.co.jp>

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From: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: David Rowley <david.rowley@2ndquadrant.com>, "Imai, Yoshikazu" <imai.yoshikazu@jp.fujitsu.com>, Amit Langote <amitlangote09@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2019-02-22T12:45:38Z
Lists: pgsql-hackers

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On 2019/02/21 11:31, Amit Langote wrote:
> On 2019/02/21 0:50, Tom Lane wrote:
>> There might be parts of this work we can salvage, though.  It seems
>> like the idea of postponing expand_inherited_tables() might be
>> something we could use anyway.
> 
> +1.  So, let's try to do things in this order:
> 
> 1. Make inheritance-expansion-at-bottom case perform better now,
> addressing at least SELECT performance in PG 12, provided we manage to get
> the patches in order in time (I'll try to post the updated
> lazy-inheritance-expansion patch later this week.)

I have updated the inheritance expansion patch.

Patch 0001 rewrites optimizer/utils/inherit.c, so that it allows
inheritance expansion to be invoked from make_one_rel().  Although the
rewrite in this version of the patch is a bit different from earlier
versions, because I needed to account for the fact that
inheritance_planner (whose rewrite I'm withdrawing) will use the same
expansion code to expand target inheritance.  So, the code now needs to
treat source-inheritance-expansion and target-inheritance-expansion cases
a bit differently.

I wanted to polish the code and various comments a bit more because the
rewritten expansion code looks different from earlier versions as I
mentioned above, but I needed to rush out today due to a family emergency
and won't be able to reply until Wednesday next week.  Sorry.

Thanks,
Amit

Commits

  1. Clean up handling of constraint_exclusion and enable_partition_pruning.

  2. Add test case exercising formerly-unreached code in inheritance_planner.

  3. Speed up planning when partitions can be pruned at plan time.

  4. Avoid crash in partitionwise join planning under GEQO.

  5. Avoid passing query tlist around separately from root->processed_tlist.

  6. Build "other rels" of appendrel baserels in a separate step.

  7. Get rid of duplicate child RTE for a partitioned table.

  8. Rearrange make_partitionedrel_pruneinfo to avoid work when we can't prune.

  9. Don't copy PartitionBoundInfo in set_relation_partition_info.

  10. Move building of child base quals out into a new function

  11. Reorganize planner code moved in b60c39759908

  12. Move inheritance expansion code into its own file

  13. Fix inherited UPDATE/DELETE with UNION ALL subqueries.

  14. Rearrange planner to save the whole PlannerInfo (subroot) for a subquery.