Re: [bug] Logical Decoding of relation rewrite with toast does not reset toast_hash

On Fri, Jul 9, 2021 at 12:22 PM Drouvot, Bertrand <bdrouvot(at)amazon(dot)com> wrote:
>
> Please find enclosed a patch proposal to:
>
> * Avoid the failed assertion on current master and generate the error message instead (should the code reach that stage).
> * Reset the toast_hash in case of relation rewrite with toast (so that the logical decoding in the above repro is working).
>

I think instead of resetting toast_hash for this case why don't we set
'relrewrite' for toast tables as well during rewrite? If we do that
then we will simply skip assembling toast chunks for the toast table.
In make_new_heap(), we are calling NewHeapCreateToastTable() to create
toast table where we can pass additional information (probably
'toastid'), if required to set 'relrewrite'. Additionally, let's add a
test case if possible for this.

BTW, I see this as an Open Item for PG-14 [1] which seems wrong to me
as this is a bug from previous versions. I am not sure who added it
but do you see any reason for this to consider as an open item for
PG-14?

[1] - https://wiki.postgresql.org/wiki/PostgreSQL_14_Open_Items
--
With Regards,
Amit Kapila.