Re: Unnecessary smgropen in {heapam_relation,index}_copy_data?

On Thu, 25 Jan 2024 at 21:43, Aleksander Alekseev <aleksander@timescale.com> wrote:
> Hi,
>
>> I find heapam_relation_copy_data() and index_copy_data() have the following code:
>>
>>         dstrel = smgropen(*newrlocator, rel->rd_backend);
>>
>>         ...
>>
>>         RelationCreateStorage(*newrlocator, rel->rd_rel->relpersistence, true);
>>
>> The smgropen() is also called by RelationCreateStorage(), why should we call
>> smgropen() explicitly here?
>>
>> I try to remove the smgropen(), and all tests passed.
>
> That's a very good question. Note that the second argument of
> smgropen() used to create dstrel changes after applying your patch.
> I'm not 100% sure whether this is significant or not.
>

Thanks for the review.

According the comments of RelationData->rd_backend, it is the backend id, if
the relation is temporary.  The differnece is RelationCreateStorage() uses
relpersistence to determinate the backend id.

> I added your patch to the nearest open commitfest so that we will not lose it:
>
> https://commitfest.postgresql.org/47/4794/

Thank you.