Horton

Re: Declarative partitioning - another take

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

View thread View on postgr.es
From: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
To: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Cc: Amit Langote <amitlangote09@gmail.com>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, Robert Haas <robertmhaas@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2016-09-27T11:19:44Z
Lists: pgsql-hackers

Attachments

On 2016/09/27 18:09, Ashutosh Bapat wrote:
>>> I tried to debug the problem somewhat. In set_append_rel_pathlist(),
>>> it finds that at least one child has a parameterized path as the
>>> cheapest path, so it doesn't create an unparameterized path for append
>>> rel. At the same time there is a parameterization common to all the
>>> children, so it doesn't create any path. There seem to be two problems
>>> here
>>> 1. The children from second level onwards may not be getting
>>> parameterized for lateral references. That seems unlikely but
>>> possible.
> 
> Did you check this? We may be missing on creating index scan paths
> with parameterization. If we fix this, we don't need to
> re-parameterize Append.

You're right.  How about the attached patch that fixes the problem along
these lines?  The problem seems to be that multi-level inheritance sets
(partitioned tables) are not handled in create_lateral_join_info(), which
means that lateral_relids and lateral_referencers of the root relation are
not being propagated to the partitions below level 1.

I'm getting concerned about one thing though - for a given *regular*
inheritance set, the root->append_rel_list would be scanned only once; But
for a *partitioned table* inheritance set, it would be scanned for every
partitioned table in the set (ie, the root table and internal partitions).

Thanks,
Amit

Commits

  1. Fix typo.

  2. Document trigger-firing behavior for inheritance/partitioning.

  3. Fire per-statement triggers on partitioned tables.

  4. Set ecxt_scantuple correctly for tuple routing.

  5. Fix interaction of partitioned tables with BulkInsertState.

  6. Avoid core dump for empty prepared statement in an aborted transaction.

  7. Fix some problems in check_new_partition_bound().

  8. Remove unnecessary arguments from partitioning functions.

  9. Fix reporting of constraint violations for table partitioning.

  10. Fix tuple routing in cases where tuple descriptors don't match.

  11. Invalid parent's relcache after CREATE TABLE .. PARTITION OF.

  12. Doc: improve documentation about inheritance.