Horton

Re: Declarative partitioning - another take

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Cc: Robert Haas <robertmhaas@gmail.com>, Amit Langote <amitlangote09@gmail.com>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2016-10-26T03:09:15Z
Lists: pgsql-hackers 
On Wed, Oct 26, 2016 at 8:27 AM, Amit Langote
<Langote_Amit_f8@lab.ntt.co.jp> wrote:
> On 2016/10/26 11:41, Amit Kapila wrote:
>> On Wed, Oct 26, 2016 at 6:36 AM, Amit Langote
>> <Langote_Amit_f8@lab.ntt.co.jp> wrote:
>>>> 1.
>>>> @@ -1775,6 +1775,12 @@ BeginCopyTo(ParseState *pstate,
>>>> {
>>>> ..
>>>> + else if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
>>>> + ereport(ERROR,
>>>> + (errcode(ERRCODE_WRONG_OBJECT_TYPE),
>>>> + errmsg("cannot copy from partitioned table \"%s\"",
>>>> + RelationGetRelationName(rel)),
>>>> + errhint("Try the COPY (SELECT ...) TO variant.")));
>>>> ..
>>>> }
>>>>
>>>> Why is this restriction?  Won't it be useful to allow it for the cases
>>>> when user wants to copy the data of all the partitions?
>>>
>>> Sure, CopyTo() can be be taught to scan leaf partitions when a partitioned
>>> table is specified, but I thought this may be fine initially.
>>>
>>
>> Okay, I don't want to add anything to your existing work unless it is
>> important.  However, I think there should be some agreement on which
>> of the restrictions are okay for first version of patch.  This can
>> avoid such questions in future from other reviewers.
>
> OK, so I assume you don't find this particular restriction problematic in
> long term.
>

I think you can keep it as you have in patch.  After posting your
updated patches, please do send a list of restrictions which this
patch is imposing based on the argument that for first version they
are not essential.

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

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.