Re: Declarative partitioning - another take

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