Re: patch: improve "user mapping not found" error message

[Peter Eisentraut]

On 23.06.23 09:45, Ian Lawrence Barwick wrote:
        if (!HeapTupleIsValid(tp))
+       {
+               ForeignServer *server = GetForeignServer(serverid);
+
                ereport(ERROR,
                                (errcode(ERRCODE_UNDEFINED_OBJECT),
-                                errmsg("user mapping not found for \"%s\"",
-                                               MappingUserName(userid))));
+                                errmsg("user mapping not found for user \"%s\", server 
\"%s\"",
+                                               MappingUserName(userid),
+                                               server->servername)));
+       }

What if the foreign server does not exist either?  Then this would show 
a "cache lookup failed" error message, which I think we should avoid.

There is existing logic for handling this in 
get_object_address_usermapping().