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Re: [Sender Address Forgery]Re: path toward faster partition pruning

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

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From: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
To: David Rowley <david.rowley@2ndquadrant.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, Beena Emerson <memissemerson@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2017-11-07T02:45:11Z
Lists: pgsql-hackers 
On 2017/11/06 21:52, David Rowley wrote:
> On 6 November 2017 at 23:01, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp> wrote:
>> OK, I have gotten rid of the min/max partition index interface and instead
>> adopted the bms_add_range() approach by including your patch to add the
>> same in the patch set (which is now 0002 in the whole set).  I have to
>> admit that it's simpler to understand the new code with just Bitmapsets to
>> look at, but I'm still a bit concerned about materializing the whole set
>> right within partition.c, although we can perhaps optimize it later.
> 
> Thanks for making that change. The code looks much more simple now.
> 
> For performance, if you're worried about a very large number of
> partitions, then I think you're better off using bms_next_member()
> rather than bms_first_member(), (likely this applies globally, but you
> don't need to worry about those).
> 
> The problem with bms_first_member is that it must always loop over the
> 0 words before it finds any bits set for each call, whereas
> bms_next_member will start on the word it was last called for. There
> will likely be a pretty big performance difference between the two
> when processing a large Bitmapset.

Ah, thanks for the explanation.  I will change it to bms_next_member() in
the next version.

>> Attached updated set of patches, including the fix to make the new pruning
>> code handle Boolean partitioning.
> 
> Thanks. I'll look over it all again starting my Tuesday morning. (UTC+13)

Thank you.

Regards,
Amit

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.