Re: Refreshing subscription relation state inside a transaction block

On Tue, Jun 13, 2017 at 4:53 PM, Petr Jelinek
<petr(dot)jelinek(at)2ndquadrant(dot)com> wrote:
> On 13/06/17 09:06, Masahiko Sawada wrote:
>> Hi,
>>
>> The commit ddd7b22b225ae41d16ceb218b387645cb9becfdc makes table sync
>> workers stop when subscription relation entry is removed. It doesn't
>> work fine inside transaction block. I think we should disallow to use
>> the following subscription DDLs inside a transaction block. Attached
>> patch.
>>
>
> Can you be more specific than "It doesn't work fine inside transaction
> block", what do you expect to happen and what actually happens?
>

If we do ALTER SUBSCRIPTION SET PUBLICATION during executing table
sync then it forcibly stops concurrently running table sync worker for
a table that had been removed from pg_subscription_rel. Then if we
rollback the transaction then these table sync worker start again from
the first. it's an rarely situation and not a damaging behavior but
what I expected is the table sync worker is stopped when the
refreshing transaction is committed.

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center