Re: [HACKERS] Function to move the position of a replication slot

On Sat, Sep 2, 2017 at 12:37 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Peter Eisentraut <peter.eisentraut@2ndquadrant.com> writes:
>> On 8/31/17 08:19, Magnus Hagander wrote:
>>> I think that, in the end, covered all the comments?
>
>> I didn't see any explanation of what this would actually be useful for.
>> I suppose you could skip over some changes you don't want replicated,
>> but how do you find to what position to skip?
>
> Um ... I can see how you might expect to skip some events in a logical
> replication stream and have a chance of things not being utterly broken.
> But how can that work for physical replication?  Missed updates are
> normally spelled "unrecoverable data corruption" at that level.

One use-case possible, even if it is easy to counter it by dropping
and recreating a slot, is to give up with what has been retained and
allow another client to reuse the same slot for a new standby.
-- 
Michael