Re: DROP SUBSCRIPTION hangs if sub is disabled in the same transaction

On 9/21/17 04:43, Masahiko Sawada wrote:
>> Once we got this patch, DROP SUBSCRIPTION is not transactional either
>> if dropping a replication slot or if the subscription got disabled in
>> a transaction block. But we disallow to do DROP SUBSCRIPTION in a
>> transaction block only in the former case. In the latter case, we
>> adopted such non-transactional behaviour. Since these behaviours would
>> be complex for users I attached the documentation patch explaining it.
>>
> Hmm, isn't there necessary to care and mention about this kind of
> inconsistent behavior in docs?

I have added documentation that certain forms of CREATE/DROP
SUBSCRIPTION cannot be run inside a transaction block, which we have
done for other such commands.

I don't think we need to go into further detail. We don't guarantee
continuous connections. If a worker is stopped and restarted in the
background as an implementation detail, then the user is not impacted.

--
Peter Eisentraut http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services