Re: logical replication syntax (was DROP SUBSCRIPTION, query cancellations and slot handling)

Petr Jelinek <petr.jelinek@2ndquadrant.com>

From: Petr Jelinek <petr.jelinek@2ndquadrant.com>
To: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: Robert Haas <robertmhaas@gmail.com>, Michael Paquier <michael.paquier@gmail.com>, PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Date: 2017-05-09T15:43:21Z
Lists: pgsql-hackers

Attachments

On 09/05/17 16:28, Peter Eisentraut wrote:
> On 5/9/17 04:39, Petr Jelinek wrote:
>>>> What we want to simulate instead is an "auto" dependency of the slot on
>>>> the subscription.  So you can drop the slot separately (subject to other
>>>> restrictions), and it is dropped automatically when the subscription is
>>>> dropped.  To avoid that, you can disassociate the slot from the
>>>> subscription, which you have implemented.
>>>>
>>>> I think we can therefore do without RESTRICT/CASCADE here.  If a slot is
>>>> associated with the subscription, it should be there when we drop the
>>>> subscription.  Otherwise, the user has to disassociate the slot and take
>>>> care of it manually.  So just keep the "cascade" behavior.
>>>>
>>>> Similarly, I wouldn't check first whether the slot exists.  If the
>>>> subscription is associated with the slot, it should be there.
>>>
>>> Here is your patch amended for that.
>>
>> I am fine with this mechanism as well.
> 
> Committed.
> 
> I also wrote a bit of documentation about slot handling for
> subscriptions, covering some of what was discussed in this thread.
> 

Great, thanks.

Here is rebased version of the other patch (the interface rework). I
also fixed the tab completion there.

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

Commits

  1. Remove the NODROP SLOT option from DROP SUBSCRIPTION