Horton

Re: [HACKERS] path toward faster partition pruning

Amit Langote <amitlangote09@gmail.com>

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From: Amit Langote <amitlangote09@gmail.com>
To: David Rowley <david.rowley@2ndquadrant.com>
Cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2018-04-07T01:50:10Z
Lists: pgsql-hackers 
On Sat, Apr 7, 2018 at 10:31 AM, David Rowley
<david.rowley@2ndquadrant.com> wrote:
> On 7 April 2018 at 12:43, David Rowley <david.rowley@2ndquadrant.com> wrote:
>> On 7 April 2018 at 12:35, Amit Langote <amitlangote09@gmail.com> wrote:
>>> So this same failure occurs on (noting the architecture):
>>>
>>> Seems to be due to that the hashing function used in partitioning
>>> gives different answer for a given set of partition key values than
>>> others.
>>
>> They all look like bigendian CPUs.
>
> I looked at all the regression test diffs for each of the servers you
> mentioned and I verified that the diffs match on each of the 7
> servers.
>
> Maybe the best solution is to pull those tests out of
> partition_prune.sql then create partition_prune_hash and just have an
> alternative .out file with the partitions which match on bigendian
> machines.
>
> We could also keep them in the same file, but that's a much bigger
> alternative file to maintain and more likely to get broken if someone
> forgets to update it.
>
> What do you think?

Yeah, that's an idea.

Is it alright though that same data may end up in different hash
partitions depending on the architecture?  IIRC, that's the way we
decided to go when using hash partitioning, but it would've been
clearer if there was already some evidence in regression tests that
that's what we've chosen, such as, some existing tests for tuple
routing.

Thanks,
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.