Re: pgsql: Clarify use of temporary tables within partition trees

On 2018/07/03 15:16, David Rowley wrote:
> On 3 July 2018 at 18:11, Michael Paquier <michael(at)paquier(dot)xyz> wrote:
>> On Tue, Jul 03, 2018 at 06:00:46PM +1200, David Rowley wrote:
>>> I think it should be backpatched to v11 and v10. Your original commit
>>> went there too. I don't see any reason to do any different here than
>>> what you did with the original commit.
>>
>> expand_partitioned_rtentry is new as of v11. Or you mean to tweak
>> expand_inherited_rtentry() perhaps? I am not sure that it is worth it
>> as the code has already diverged between 10 and 11.
>
> Oh right. I'd forgotten that changed in v11. I think the v10 code is
> fine as is then.

Sorry for jumping in late here. I have a comment on the patch.

+ /* if there are no partitions then treat this as non-inheritance case. */
+ if (partdesc->nparts == 0)
+ {
+ parentrte->inh = false;
+ return;
+ }
+

Why is this not near the beginning of expand_partitioned_rtentry()?

Also, ISTM, this code would be unreachable because
expand_inherited_rtentry would not call here if the above if statement is
true, no?

I see the following two blocks in expand_inherited_rtentry before one gets
to the call to expand_partitioned_rtentry:

if (!has_subclass(parentOID))
{
/* Clear flag before returning */
rte->inh = false;
return;
}

and

if (list_length(inhOIDs) < 2)
{
/* Clear flag before returning */
rte->inh = false;
return;
}

Thanks,
Amit