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: "Tsunakawa, Takayuki" <tsunakawa.takay@jp.fujitsu.com>, 'David Rowley' <david.rowley@2ndquadrant.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2019-01-22T07:00:54Z
Lists: pgsql-hackers 
Tsunakawa-san

Thanks for giving the information.
I didn't use it yet, but I just used perf to clarify the difference of before and after the creation of the generic plan, and I noticed that usage of hash_seq_search() is increased about 3% in EXECUTE queries after the creation of the generic plan.

What I understand so far is about 10,000 while loops at total (4098+4098+some extra) is needed in hash_seq_search() in EXECUTE query after the creation of the generic plan.
10,000 while loops takes about 10 microsec (of course, we can't estimate correct time), and the difference of the latency between 5th and 7th EXECUTE is about 8 microsec, I currently think this causes the difference.

I don't know this problem relates to Amit-san's patch, but I'll continue to investigate it.

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.