Check relkind of tables in CREATE/ALTER SUBSCRIPTION

We used to only check for a supported relkind on the subscriber during
replication, which is needed to ensure that the setup is valid and we
don't crash.  But it's also useful to tell the user immediately when
CREATE or ALTER SUBSCRIPTION is executed that the relation being added
to the subscription is not of a supported relkind.

Author: Petr Jelinek <petr.jelinek@2ndquadrant.com>
Reported-by: tushar <tushar.ahuja@enterprisedb.com>

src/backend/commands/subscriptioncmds.c

@@ -33,6 +33,8 @@
 #include "commands/event_trigger.h"
 #include "commands/subscriptioncmds.h"
 
+#include "executor/executor.h"
+
 #include "nodes/makefuncs.h"
 
 #include "replication/logicallauncher.h"
@@ -417,6 +419,10 @@ CreateSubscription(CreateSubscriptionStmt *stmt, bool isTopLevel)
 
 				relid = RangeVarGetRelid(rv, AccessShareLock, false);
 
+				/* Check for supported relkind. */
+				CheckSubscriptionRelkind(get_rel_relkind(relid),
+										 rv->schemaname, rv->relname);
+
 				SetSubscriptionRelState(subid, relid, table_state,
 										InvalidXLogRecPtr);
 			}
@@ -529,6 +535,11 @@ AlterSubscription_refresh(Subscription *sub, bool copy_data)
 		Oid			relid;
 
 		relid = RangeVarGetRelid(rv, AccessShareLock, false);
+
+		/* Check for supported relkind. */
+		CheckSubscriptionRelkind(get_rel_relkind(relid),
+								 rv->schemaname, rv->relname);
+
 		pubrel_local_oids[off++] = relid;
 
 		if (!bsearch(&relid, subrel_local_oids,

src/backend/executor/execReplication.c

@@ -551,3 +551,23 @@ CheckCmdReplicaIdentity(Relation rel, CmdType cmd)
 						RelationGetRelationName(rel)),
 				 errhint("To enable deleting from the table, set REPLICA IDENTITY using ALTER TABLE.")));
 }
+
+
+/*
+ * Check if we support writing into specific relkind.
+ *
+ * The nspname and relname are only needed for error reporting.
+ */
+void
+CheckSubscriptionRelkind(char relkind, const char *nspname,
+						 const char *relname)
+{
+	/*
+	 * We currently only support writing to regular tables.
+	 */
+	if (relkind != RELKIND_RELATION)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("logical replication target relation \"%s.%s\" is not a table",
+						nspname, relname)));
+}

src/backend/replication/logical/relation.c

@@ -20,6 +20,7 @@
 #include "access/sysattr.h"
 #include "catalog/namespace.h"
 #include "catalog/pg_subscription_rel.h"
+#include "executor/executor.h"
 #include "nodes/makefuncs.h"
 #include "replication/logicalrelation.h"
 #include "replication/worker_internal.h"
@@ -258,15 +259,9 @@ logicalrep_rel_open(LogicalRepRelId remoteid, LOCKMODE lockmode)
 							remoterel->nspname, remoterel->relname)));
 		entry->localrel = heap_open(relid, NoLock);
 
-		/*
-		 * We currently only support writing to regular and partitioned
-		 * tables.
-		 */
-		if (entry->localrel->rd_rel->relkind != RELKIND_RELATION)
-			ereport(ERROR,
-					(errcode(ERRCODE_WRONG_OBJECT_TYPE),
-					 errmsg("logical replication target relation \"%s.%s\" is not a table",
-							remoterel->nspname, remoterel->relname)));
+		/* Check for supported relkind. */
+		CheckSubscriptionRelkind(entry->localrel->rd_rel->relkind,
+								 remoterel->nspname, remoterel->relname);
 
 		/*
 		 * Build the mapping of local attribute numbers to remote attribute

src/include/executor/executor.h

@@ -535,5 +535,7 @@ extern void ExecSimpleRelationDelete(EState *estate, EPQState *epqstate,
 						 TupleTableSlot *searchslot);
 extern void CheckCmdReplicaIdentity(Relation rel, CmdType cmd);
 
+extern void CheckSubscriptionRelkind(char relkind, const char *nspname,
+									 const char *relname);
 
 #endif   /* EXECUTOR_H  */