Horton

Re: Declarative partitioning - another take

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Cc: Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, Amit Langote <amitlangote09@gmail.com>, Pg Hackers <pgsql-hackers@postgresql.org>, pgsql-hackers-owner@postgresql.org
Date: 2017-04-28T16:25:04Z
Lists: pgsql-hackers 
 On Fri, Apr 28, 2017 at 2:13 AM, Amit Langote
<Langote_Amit_f8@lab.ntt.co.jp> wrote:
> It seems to me that there is no difference in behavior between
> inheritance-based and declarative partitioning as far as statement-level
> triggers are concerned (at least currently).  In both the cases, we fire
> statement-level triggers only for the table specified in the command.

OK.

>>> By the way, code changes I made in the attached are such that a subsequent
>>> patch could implement firing statement-level triggers of all the tables in
>>> a partition hierarchy, which it seems we don't want to do.  Should then
>>> the code be changed to not create ResultRelInfos of all the tables but
>>> only the root table (the one mentioned in the command)?  You will see that
>>> the patch adds fields named es_nonleaf_result_relations and
>>> es_num_nonleaf_result_relations, whereas just es_root_result_relation
>>> would perhaps do, for example.
>>
>> It seems better not to create any ResultRelInfos that we don't
>> actually need, so +1 for such a revision to the patch.
>
> OK, done.  It took a bit more work than I thought.

So, this seems weird, because rootResultRelIndex is initialized even
when splan->partitioned_rels == NIL, but isn't actually valid in that
case.  ExecInitModifyTable seems to think it's always valid, though.

I think the way that you've refactored fireBSTriggers and
fireASTriggers is a bit confusing.  Instead of splitting out a
separate function, how about just having the existing function begin
with if (node->rootResultRelInfo) resultRelInfo =
node->rootResultRelInfo; else resultRelInfo = node->resultRelInfo; ?
I think the way you've coded it is a holdover from the earlier design
where you were going to call it multiple times, but now that's not
needed.

Looks OK, otherwise.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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.