Re: [HACKERS] logical decoding of two-phase transactions

On Tue, Jan 5, 2021 at 5:19 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:

>
> I have reviewed this test case patch and have the below comments:
>
> 1.
> +step "s1checkpoint" { CHECKPOINT; }
> ...
> +step "s2alter" { ALTER TABLE do_write ADD COLUMN addedbys2 int; }
>
> I don't see the need for the above steps and we should be able to
> generate the required scenario without these as well. Is there any
> reason to keep those?

Removed.
>
> 2.
> "s3c""s1insert"
>
> space is missing between these two.

Updated.

>
> 3.
> +# Force building of a consistent snapshot between a PREPARE and
> COMMIT PREPARED.
> +# Ensure that the whole transaction is decoded fresh at the time of
> COMMIT PREPARED.
> +permutation "s2b" "s2txid" "s1init" "s3b" "s3txid" "s2alter" "s2c"
> "s2b" "s2insert" "s2prepare" "s3c""s1insert" "s1checkpoint" "s1start"
> "s2commit" "s1start"
>
> I think we can update the above comments to indicate how and which
> important steps help us to realize the required scenario. See
> subxact_without_top.spec for reference.

Added more comments to explain the state change of logical decoding.

> 4.
> +step "s2c" { COMMIT; }
> ...
> +step "s2prepare" { PREPARE TRANSACTION 'test1'; }
> +step "s2commit" { COMMIT PREPARED 'test1'; }
>
> s2c and s2commit seem to be confusing names as both sounds like doing
> the same thing. How about changing s2commit to s2cp and s2prepare to
> s2p?

Updated.

I've addressed the above comments and the patch is attached. I've
called it v36-0007.

regards,
Ajin Cherian
Fujitsu Australia