Re: Binary support for pgoutput plugin

On Fri, 14 Jun 2019 at 15:42, Dave Cramer <davecramer@gmail.com> wrote:

>
> Dave Cramer
>
>
> On Fri, 14 Jun 2019 at 14:36, Tomas Vondra <tomas.vondra@2ndquadrant.com>
> wrote:
>
>> On Wed, Jun 12, 2019 at 10:35:48AM -0400, Dave Cramer wrote:
>> >On Mon, 10 Jun 2019 at 07:49, Petr Jelinek <petr.jelinek@2ndquadrant.com
>> >
>> >wrote:
>> >
>> >> Hi,
>> >>
>> >> On 10/06/2019 13:27, Dave Cramer wrote:
>> >> > So back to binary output.
>> >> >
>> >> > From what I can tell the place to specify binary options would be in
>> the
>> >> > create publication and or in replication slots?
>> >> >
>> >> > The challenge as I see it is that the subscriber would have to be
>> able
>> >> > to decode binary output.
>> >> >
>> >> > Any thoughts on how to handle this? At the moment I'm assuming that
>> this
>> >> > would only work for subscribers that knew how to handle binary.
>> >> >
>> >>
>> >> Given that we don't need to write anything extra to WAL on upstream to
>> >> support binary output, why not just have the request for binary data as
>> >> an option for the pgoutput and have it chosen dynamically? Then it's
>> the
>> >> subscriber who asks for binary output via option(s) to
>> START_REPLICATION.
>> >>
>> >
>> >If I understand this correctly this would add something to the
>> CREATE/ALTER
>> >SUBSCRIPTION commands in the WITH clause.
>> >Additionally another column would be required for pg_subscription for the
>> >binary option.
>> >Does it make sense to add an options column which would just be a comma
>> >separated string?
>> >Not that I have future options in mind but seems like something that
>> might
>> >come up in the future.
>> >
>>
>> I'd just add a boolean column to the catalog. That's what I did in the
>> patch adding support for streaming in-progress transactions. I don't think
>> we expect many additional parameters, so it makes little sense to optimize
>> for that case.
>>
>
> Which is what I have done. Thanks
>
> I've attached both patches for comments.
> I still have to add documentation.
>
> Regards,
>
> Dave
>

Additional patch for documentation.


Dave Cramer