Horton

Re: [HACKERS] path toward faster partition pruning

David Rowley <david.rowley@2ndquadrant.com>

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From: David Rowley <david.rowley@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Jesper Pedersen <jesper.pedersen@redhat.com>, Robert Haas <robertmhaas@gmail.com>, Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>, Amit Langote <amitlangote09@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Beena Emerson <memissemerson@gmail.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2018-04-04T04:03:31Z
Lists: pgsql-hackers 
On 4 April 2018 at 16:00, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> David Rowley <david.rowley@2ndquadrant.com> writes:
>> It's true that the const simplification code will generally rewrite
>> most NOT(clause) to use the negator operator, but if the operator does
>> not have a negator it can't do this.
>> ...
>> At the moment pruning does not work for this case at all. Perhaps it should?
>
> It's hard to see why we'd expend extra effort to optimize such situations.
> The right answer would invariably be to fix the inadequate operator
> definition, because missing the negator link would hobble many other
> cases besides this.
>
> Now if you can show a case where the extra smarts would be useful
> without presuming a badly-written opclass, it's a different matter.

Okay, well that certainly sounds like less work.

In that case, the comment which claims we handle the NOT clauses needs
to be updated to mention that we only handle boolean NOT clauses and
don't optimize the remainder.


-- 
 David Rowley                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services

Commits

  1. Fix assorted partition pruning bugs

  2. Make gen_partprune_steps static

  3. Remove useless 'default' clause

  4. Reorganize partitioning code

  5. Use custom hash opclass for hash partition pruning

  6. Blindly attempt to fix sepgsql tests broken due to 9fdb675fc5.

  7. Attempt to fix endianess issues in new hash partition test.

  8. Faster partition pruning

  9. For partitionwise join, match on partcollation, not parttypcoll.

  10. Revise API for partition bound search functions.

  11. Revise API for partition_rbound_cmp/partition_rbound_datum_cmp.

  12. Fix possible crash in partition-wise join.

  13. Refactor code for partition bound searching

  14. New C function: bms_add_range

  15. Add extensive tests for partition pruning.

  16. Add null test to partition constraint for default range partitions.

  17. Remove BufFile's isTemp flag.

  18. Make OWNER TO subcommand mention consistent

  19. Fix index matching for operators with mixed collatable/noncollatable inputs.