Re: [HACKERS] Logical Replication WIP

On 02/01/17 05:23, Steve Singer wrote:
> On 12/30/2016 05:53 AM, Petr Jelinek wrote:
>> Hi,
>>
>> I rebased this for the changes made to inheritance and merged in the
>> fixes that I previously sent separately.
>>
>>
>>
> 
> 
> I'm not sure if the following is expected or not
> 
> I have 1 publisher and 1 subscriber.
> I then do pg_dump on my subscriber
> ./pg_dump -h localhost --port 5441 --include-subscriptions
> --no-create-subscription-slot test|./psql --port 5441 test_b
> 
> I now can't do a drop database test_b  , which is expected
> 
> but I can't drop the subscription either
> 
> 
> test_b=# drop subscription mysub;
> ERROR:  could not drop replication origin with OID 1, in use by PID 24996
> 
>  alter subscription mysub disable;
> ALTER SUBSCRIPTION
> drop subscription mysub;
> ERROR:  could not drop replication origin with OID 1, in use by PID 24996
> 
> drop subscription mysub nodrop slot;
> 
> doesn't work either.  If I first drop the working/active subscription on
> the original 'test' database it works but I can't seem to drop the
> subscription record on test_b
> 

I guess this is because replication origins are pg instance global and
we use subscription name for origin name internally. Maybe we need to
prefix/suffix it with db oid or something like that, but that's
problematic a bit as well as they both have same length limit. I guess
we could use subscription OID as replication origin name which is
somewhat less user friendly in terms of debugging but would be unique.

--  Petr Jelinek                  http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training &
Services