Re: Using test_ddl_deparse as an extension

On 2018-Jul-25, Jeremy Finzel wrote:

> I am interested in using the exact functionality in test_ddl_deparse which
> provides the sub command types for alter table statements. I would prefer
> to leverage this code which has already been vetted by the community, and
> also not just duplicate this code myself, or package it up myself.
>
> It would be nice to just use the extension. But I'm interested to hear
> what recommendations could be given for my use case (for that matter - what
> is the recommendation to anyone wanting to use the exact functionality
> provided in a postgres test module).
>
> My specific intention is for sending DDL via logical replication, and
> ignoring, for example, enable/disable trigger statements when I am using
> selective replication.

The design for the intended functionality was to emit a JSON blob that
could be modified or examined programmatically; so you would be able to
obtain specific bits of knowledge (is this going into schema XYZ? etc).
There was a module that was about 90% complete before I abandoned it
because of changing priorities, needed just "a little push" and I never
got around to doing that. Alexander Shulgin spent some time with it and
moved it forward a good bit, but I didn't get time to review his work,
so he understandably gave up. I think with a little bit more effort we
could get it in core, which I'd love ...

That test code was more a placeholder to have *something* to ensure we
didn't completely break the feature, but I don't really see it as a good
way forward for the feature. Let's not turn it into a production-level
feature.

--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services