Re: Assertion failure while streaming toasted data

On Tue, May 25, 2021 at 1:49 PM Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:

> On Tue, May 25, 2021 at 1:45 PM Pavan Deolasee <pavan(dot)deolasee(at)gmail(dot)com>
> wrote:
> >
> > I am not entirely sure if it works correctly. I'd tried something
> similar, but the downstream node using
> > my output plugin gets NULL values for the toast columns. It's a bit
> hard to demonstrate that with the
> > test_decoding plugin, but if you have some other mechanism to test that
> change with an actual downstream
> > node receiving and applying changes, it will be useful to test with that.
>
> Okay, I will test that. Thanks.
>
>
I modified test_decoding to print the tuples (like in the non-streamed
case) and included your proposed fix. PFA

When the transaction is streamed, I see:
```
+ opening a streamed block for transaction
+ table public.toasted: INSERT: id[integer]:9001 other[text]:'bbb'
data[text]:'ccc'
+ table public.toasted: INSERT: id[integer]:9002 other[text]:'ddd'
data[text]:'eee'
+ table public.toasted: INSERT: id[integer]:9003 other[text]:'bar'
data[text]:unchanged-toast-datum
<snipped>
```

For a non-streamed case, the `data[text]` column shows the actual data.
That probably manifests into NULL data when downstream handles it.

Thanks,
Pavan

--
Pavan Deolasee
EnterpriseDB: https://www.enterprisedb.com