Re: Support logical replication of DDLs

On Fri, Apr 28, 2023 at 5:11 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Tue, Apr 25, 2023 at 9:28 AM Zhijie Hou (Fujitsu)
> <houzj(dot)fnst(at)fujitsu(dot)com> wrote:
> >
>
> I have a few high-level comments on the deparsing approach used in the
> patch. As per my understanding, we first build an ObjTree from the DDL
> command, then convert the ObjTree to Jsonb which is then converted to
> a JSON string. Now, in the consecutive patch, via publication event
> triggers, we get the JSON string via the conversions mentioned, WAL
> log it, which then walsender will send to the subscriber, which will
> convert the JSON string back to the DDL command and execute it.
>
> Now, I think we can try to eliminate this entire ObjTree machinery and
> directly from the JSON blob during deparsing. We have previously also
> discussed this in an email chain at [1]. I think now the functionality
> of JSONB has also been improved and we should investigate whether it
> is feasible to directly use JSONB APIs to form the required blob.

+1.
I will investigate this and will share my findings.

thanks
Shveta