Horton

RE: speeding up planning with partitions

Imai, Yoshikazu <imai.yoshikazu@jp.fujitsu.com>

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From: "Imai, Yoshikazu" <imai.yoshikazu@jp.fujitsu.com>
To: 'Tom Lane' <tgl@sss.pgh.pa.us>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Cc: Imai Yoshikazu <yoshikazu_i443@live.jp>, "jesper.pedersen@redhat.com" <jesper.pedersen@redhat.com>, 'Amit Langote' <amitlangote09@gmail.com>, "David Rowley" <david.rowley@2ndquadrant.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Robert Haas <robertmhaas@gmail.com>, "Justin Pryzby" <pryzby@telsasoft.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2019-03-25T01:47:23Z
Lists: pgsql-hackers

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On Fri, Mar 22, 2019 at 9:07 PM, Tom Lane wrote:
> BTW, it strikes me that we could take advantage of the fact that baserels
> must all appear before otherrels in the rel array, by having loops over
> that array stop early if they're only interested in baserels.  We could
> either save the index of the last baserel, or just extend the loop logic
> to fall out upon hitting an otherrel.
> Seems like this'd save some cycles when there are lots of partitions,
> although perhaps loops like that would be fast enough to not matter.

Actually, this speeds up planning time little when scanning a lot of otherrels like selecting thousands of partitions. I tested below.

* rt with 8192 partitions
* execute "select * from rt;" for 60 seconds.

[results]
HEAD: 4.19 TPS (4.06, 4.34, 4.17)
(v34 patches) + (looping over only baserels): 4.26 TPS (4.31, 4.28, 4.19)


Attached is the diff I used for this test.

--
Yoshikazu Imai

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.