Re: Added schema level support for publication.

One issue here is that the code to update publication type is missing 
in AlterPublicationTables for SET TABLE command.

More broadly, I am not clear about the behaviour of the patch when a
publication is created to publish only certain tables, and is later altered to publish 
a whole schema. I think such behaviour is legitimate. However,
AFAIU as per current code we can't update the publication type 
from PUBTYPE_TABLE to PUBTYPE_SCHEMA. 

I have some review comments as follows:
1. 
In ConvertSchemaSpecListToOidList(List *schemas) function: 
 +     search_path = fetch_search_path(false);
 +                               nspname = get_namespace_name(linitial_oid(search_path));
 +                               if (nspname == NULL)    /* recently-deleted namespace? */
 +                                       ereport(ERROR,
 +                                                       errcode(ERRCODE_UNDEFINED_SCHEMA),
 +                                                       errmsg("no schema has been selected"));
 +
 +                               schemoid = get_namespace_oid(nspname, false);
 +                               break;

The call get_namespace_oid() is perhaps not needed as fetch_search_path already fetches oids and simply
doing Schema oid = liinital_oid(search_path)); should be enough.

2. In the same function should there be an if else condition block instead of a switch case as
there are only two cases.


Thank you,

Rahila Syed