Re: [18] CREATE SUBSCRIPTION ... SERVER

On Sat, 1 Mar 2025 at 04:35, Jeff Davis <pgsql(at)j-davis(dot)com> wrote:
>
> On Mon, 2024-12-16 at 20:05 -0800, Jeff Davis wrote:
> > On Wed, 2024-10-30 at 08:08 -0700, Jeff Davis wrote:
> >
>
> Rebased v14.
>
> The approach has changed multiple times. It starte off with more in-
> core code, but in response to review feedback, has become more
> decoupled from core and more coupled to postgres_fdw.
>
> But the patch has been about the same (just rebases) since March of
> last year, and hasn't gotten feedback since. I still think it's a nice
> feature, but I'd like some feedback on the externals of the feature.
>
> As a note, this will require a version bump for postgres_fdw for the
> new connection method.
>
Hi Jeff,

I reviewed the patch and I have a comment:

If version is >=18, the query will have 'suboriginremotelsn',
'subenabled', 'subfailover' twice.

if (fout->remoteVersion >= 170000)
appendPQExpBufferStr(query,
- " s.subfailover\n");
+ " s.subfailover,\n");
else
appendPQExpBuffer(query,
- " false AS subfailover\n");
+ " false AS subfailover,\n");
+
+ if (dopt->binary_upgrade && fout->remoteVersion >= 180000)
+ appendPQExpBufferStr(query, " fs.srvname AS subservername,\n"
+ " o.remote_lsn AS suboriginremotelsn,\n"
+ " s.subenabled,\n"
+ " s.subfailover\n");
+ else
+ appendPQExpBufferStr(query, " NULL AS subservername,\n"
+ " NULL AS suboriginremotelsn,\n"
+ " false AS subenabled,\n"
+ " false AS subfailover\n");

query formed is something like:
"SELECT s.tableoid, s.oid, s.subname,\n s.subowner,\n s.subconninfo,
s.subslotname, s.subsynccommit,\n s.subpublications,\n s.subbinary,\n
s.substream,\n s.subtwophasestate,\n s.subdisableonerr,\n
s.subpasswordrequired,\n s.subrunasowner,\n s.suborigin,\n NULL AS
suboriginremotelsn,\n false AS subenabled,\n s.subfailover,\n NULL AS
subservername,\n NULL AS suboriginremotelsn,\n false AS subenabled,\n
false AS subfailover\nFROM pg_subscription s\nWHERE s.subdbid =
(SELECT oid FROM pg_database\n.."

is it expected?

Thanks and Regards,
Shlok Kyal