RE: Added schema level support for publication.

On Monday, July 12, 2021 5:36 PM vignesh C <vignesh21@gmail.com> wrote:
> 
> Thanks for reporting this issue, this issue is fixed in the v10 patch
> attached at [1].
> [1] - https://www.postgresql.org/message-id/CALDaNm2%2BtR%2B8R-
> sD1CSyMbZcZbkintZE-avefjsp7LCkm6HMmw%40mail.gmail.com

Thanks for fixing it.

By applying your V10 patch, I saw three problems, please have a look.

1. An issue about pg_dump. 
When public schema was published, the publication was created in the output file, but public schema was not added to
it.(Other schemas could be added as expected.)
 

I looked into it and found that selectDumpableNamespace function marks DUMP_COMPONENT_DEFINITION as needless when the
schemais public, leading to schema public is ignored in getPublicationSchemas. So we'd better check whether schemas
shouldbe dumped in another way.
 

I tried to fix it with the following change, please have a look. (Maybe we also need to add some comments for it.)

diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index f6b4f12648..a327d2568b 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -4206,7 +4206,8 @@ getPublicationSchemas(Archive *fout, NamespaceInfo nspinfo[], int numSchemas)
                 * Ignore publication membership of schemas whose definitions are not
                 * to be dumped.
                 */
-               if (!(nsinfo->dobj.dump & DUMP_COMPONENT_DEFINITION))
+               if (!((nsinfo->dobj.dump & DUMP_COMPONENT_DEFINITION)
+                       || (strcmp(nsinfo->dobj.name, "public") == 0 && nsinfo->dobj.dump != DUMP_COMPONENT_NONE)))
                        continue;

                pg_log_info("reading publication membership for schema \"%s\"",

2. improper behavior for system schema
I found I could create publication for system schema, such as pg_catalog. I think it's better to report an error
messagehere, just like creating publication for system table is unallowed.
 

3. fix for dumpPublicationSchema
Should we add a declaration for it and add const decorations to the it's second parameter? Like other similar
functions.

Regards
Tang