Re: UPDATE of partition key

On 2017/07/04 17:25, Etsuro Fujita wrote:
> On 2017/07/03 18:54, Amit Langote wrote:
>> On 2017/07/02 20:10, Robert Haas wrote:
>>> That
>>> seems pretty easy to do - just have expand_inherited_rtentry() notice
>>> that it's got a partitioned table and call
>>> RelationGetPartitionDispatchInfo() instead of find_all_inheritors() to
>>> produce the list of OIDs.
> Seems like a good idea.
>
>> Interesting idea.
>>
>> If we are going to do this, I think we may need to modify
>> RelationGetPartitionDispatchInfo() a bit or invent an alternative that
>> does not do as much work. Currently, it assumes that it's only ever
>> called by ExecSetupPartitionTupleRouting() and hence also generates
>> PartitionDispatchInfo objects for partitioned child tables. We don't need
>> that if called from within the planner.
>>
>> Actually, it seems that RelationGetPartitionDispatchInfo() is too coupled
>> with its usage within the executor, because there is this comment:
>>
>> /*
>> * We keep the partitioned ones open until we're done using the
>> * information being collected here (for example, see
>> * ExecEndModifyTable).
>> */
>
> Yeah, we need some refactoring work. Is anyone working on that?

I would like to take a shot at that if someone else hasn't already cooked
up a patch. Working on making RelationGetPartitionDispatchInfo() a
routine callable from both within the planner and the executor should be a
worthwhile effort.

Thanks,
Amit