Logical replication

- Add PUBLICATION catalogs and DDL
- Add SUBSCRIPTION catalog and DDL
- Define logical replication protocol and output plugin
- Add logical replication workers

From: Petr Jelinek <petr@2ndquadrant.com>
Reviewed-by: Steve Singer <steve@ssinger.info>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Erik Rijkers <er@xs4all.nl>
Reviewed-by: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>

src/backend/commands/Makefile

@@ -17,9 +17,9 @@ OBJS = amcmds.o aggregatecmds.o alter.o analyze.o async.o cluster.o comment.o \
 	dbcommands.o define.o discard.o dropcmds.o \
 	event_trigger.o explain.o extension.o foreigncmds.o functioncmds.o \
 	indexcmds.o lockcmds.o matview.o operatorcmds.o opclasscmds.o \
-	policy.o portalcmds.o prepare.o proclang.o \
-	schemacmds.o seclabel.o sequence.o tablecmds.o tablespace.o trigger.o \
-	tsearchcmds.o typecmds.o user.o vacuum.o vacuumlazy.o \
-	variable.o view.o
+	policy.o portalcmds.o prepare.o proclang.o publicationcmds.o \
+	schemacmds.o seclabel.o sequence.o subscriptioncmds.o tablecmds.o \
+	tablespace.o trigger.o tsearchcmds.o typecmds.o user.o vacuum.o \
+	vacuumlazy.o variable.o view.o
 
 include $(top_srcdir)/src/backend/common.mk

src/backend/commands/alter.c

@@ -45,7 +45,9 @@
 #include "commands/extension.h"
 #include "commands/policy.h"
 #include "commands/proclang.h"
+#include "commands/publicationcmds.h"
 #include "commands/schemacmds.h"
+#include "commands/subscriptioncmds.h"
 #include "commands/tablecmds.h"
 #include "commands/tablespace.h"
 #include "commands/trigger.h"
@@ -770,6 +772,14 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
 			return AlterEventTriggerOwner(strVal(linitial(stmt->object)),
 										  newowner);
 
+		case OBJECT_PUBLICATION:
+			return AlterPublicationOwner(strVal(linitial(stmt->object)),
+										 newowner);
+
+		case OBJECT_SUBSCRIPTION:
+			return AlterSubscriptionOwner(strVal(linitial(stmt->object)),
+										  newowner);
+
 			/* Generic cases */
 		case OBJECT_AGGREGATE:
 		case OBJECT_COLLATION:

src/backend/commands/dbcommands.c

@@ -37,6 +37,7 @@
 #include "catalog/pg_authid.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_db_role_setting.h"
+#include "catalog/pg_subscription.h"
 #include "catalog/pg_tablespace.h"
 #include "commands/comment.h"
 #include "commands/dbcommands.h"
@@ -790,6 +791,7 @@ dropdb(const char *dbname, bool missing_ok)
 	int			npreparedxacts;
 	int			nslots,
 				nslots_active;
+	int			nsubscriptions;
 
 	/*
 	 * Look up the target database's OID, and get exclusive lock on it. We
@@ -874,6 +876,21 @@ dropdb(const char *dbname, bool missing_ok)
 						dbname),
 				 errdetail_busy_db(notherbackends, npreparedxacts)));
 
+	/*
+	 * Check if there are subscriptions defined in the target database.
+	 *
+	 * We can't drop them automatically because they might be holding
+	 * resources in other databases/instances.
+	 */
+	if ((nsubscriptions = CountDBSubscriptions(db_id)) > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_IN_USE),
+				 errmsg("database \"%s\" is being used by logical replication subscription",
+						dbname),
+				 errdetail_plural("There is %d subscription.",
+								  "There are %d subscriptions.",
+								  nsubscriptions, nsubscriptions)));
+
 	/*
 	 * Remove the database's tuple from pg_database.
 	 */

src/backend/commands/define.c

@@ -319,3 +319,31 @@ defGetTypeLength(DefElem *def)
 					def->defname, defGetString(def))));
 	return 0;					/* keep compiler quiet */
 }
+
+/*
+ * Extract a list of string values (otherwise uninterpreted) from a DefElem.
+ */
+List *
+defGetStringList(DefElem *def)
+{
+	ListCell   *cell;
+
+	if (def->arg == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("%s requires a parameter",
+						def->defname)));
+	if (nodeTag(def->arg) != T_List)
+		elog(ERROR, "unrecognized node type: %d", (int) nodeTag(def->arg));
+
+	foreach(cell, (List *)def->arg)
+	{
+		Node	   *str = (Node *) lfirst(cell);
+
+		if (!IsA(str, String))
+			elog(ERROR, "unexpected node type in name list: %d",
+				 (int) nodeTag(str));
+	}
+
+	return (List *) def->arg;
+}

src/backend/commands/dropcmds.c

@@ -441,6 +441,10 @@ does_not_exist_skipping(ObjectType objtype, List *objname, List *objargs)
 				}
 			}
 			break;
+		case OBJECT_PUBLICATION:
+			msg = gettext_noop("publication \"%s\" does not exist, skipping");
+			name = NameListToString(objname);
+			break;
 		default:
 			elog(ERROR, "unrecognized object type: %d", (int) objtype);
 			break;

src/backend/commands/event_trigger.c

@@ -106,11 +106,13 @@ static event_trigger_support_data event_trigger_support[] = {
 	{"OPERATOR CLASS", true},
 	{"OPERATOR FAMILY", true},
 	{"POLICY", true},
+	{"PUBLICATION", true},
 	{"ROLE", false},
 	{"RULE", true},
 	{"SCHEMA", true},
 	{"SEQUENCE", true},
 	{"SERVER", true},
+	{"SUBSCRIPTION", true},
 	{"TABLE", true},
 	{"TABLESPACE", false},
 	{"TRANSFORM", true},
@@ -1103,9 +1105,12 @@ EventTriggerSupportsObjectType(ObjectType obtype)
 		case OBJECT_OPERATOR:
 		case OBJECT_OPFAMILY:
 		case OBJECT_POLICY:
+		case OBJECT_PUBLICATION:
+		case OBJECT_PUBLICATION_REL:
 		case OBJECT_RULE:
 		case OBJECT_SCHEMA:
 		case OBJECT_SEQUENCE:
+		case OBJECT_SUBSCRIPTION:
 		case OBJECT_TABCONSTRAINT:
 		case OBJECT_TABLE:
 		case OBJECT_TRANSFORM:
@@ -1168,6 +1173,9 @@ EventTriggerSupportsObjectClass(ObjectClass objclass)
 		case OCLASS_EXTENSION:
 		case OCLASS_POLICY:
 		case OCLASS_AM:
+		case OCLASS_PUBLICATION:
+		case OCLASS_PUBLICATION_REL:
+		case OCLASS_SUBSCRIPTION:
 			return true;
 	}
 

src/backend/commands/publicationcmds.c

@@ -0,0 +1,754 @@
+/*-------------------------------------------------------------------------
+ *
+ * publicationcmds.c
+ *		publication manipulation
+ *
+ * Copyright (c) 2016, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *		publicationcmds.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "funcapi.h"
+#include "miscadmin.h"
+
+#include "access/genam.h"
+#include "access/hash.h"
+#include "access/heapam.h"
+#include "access/htup_details.h"
+#include "access/xact.h"
+
+#include "catalog/catalog.h"
+#include "catalog/indexing.h"
+#include "catalog/namespace.h"
+#include "catalog/objectaccess.h"
+#include "catalog/objectaddress.h"
+#include "catalog/pg_inherits_fn.h"
+#include "catalog/pg_type.h"
+#include "catalog/pg_publication.h"
+#include "catalog/pg_publication_rel.h"
+
+#include "commands/dbcommands.h"
+#include "commands/defrem.h"
+#include "commands/event_trigger.h"
+#include "commands/publicationcmds.h"
+
+#include "utils/array.h"
+#include "utils/builtins.h"
+#include "utils/catcache.h"
+#include "utils/fmgroids.h"
+#include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/rel.h"
+#include "utils/syscache.h"
+
+/* Same as MAXNUMMESSAGES in sinvaladt.c */
+#define MAX_RELCACHE_INVAL_MSGS 4096
+
+static List *OpenTableList(List *tables);
+static void CloseTableList(List *rels);
+static void PublicationAddTables(Oid pubid, List *rels, bool if_not_exists,
+					 AlterPublicationStmt *stmt);
+static void PublicationDropTables(Oid pubid, List *rels, bool missing_ok);
+
+static void
+parse_publication_options(List *options,
+						  bool *publish_insert_given,
+						  bool *publish_insert,
+						  bool *publish_update_given,
+						  bool *publish_update,
+						  bool *publish_delete_given,
+						  bool *publish_delete)
+{
+	ListCell   *lc;
+
+	*publish_insert_given = false;
+	*publish_update_given = false;
+	*publish_delete_given = false;
+
+	/* Defaults are true */
+	*publish_insert = true;
+	*publish_update = true;
+	*publish_delete = true;
+
+	/* Parse options */
+	foreach (lc, options)
+	{
+		DefElem    *defel = (DefElem *) lfirst(lc);
+
+		if (strcmp(defel->defname, "publish insert") == 0)
+		{
+			if (*publish_insert_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			*publish_insert_given = true;
+			*publish_insert = defGetBoolean(defel);
+		}
+		else if (strcmp(defel->defname, "nopublish insert") == 0)
+		{
+			if (*publish_insert_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			*publish_insert_given = true;
+			*publish_insert = !defGetBoolean(defel);
+		}
+		else if (strcmp(defel->defname, "publish update") == 0)
+		{
+			if (*publish_update_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			*publish_update_given = true;
+			*publish_update = defGetBoolean(defel);
+		}
+		else if (strcmp(defel->defname, "nopublish update") == 0)
+		{
+			if (*publish_update_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			*publish_update_given = true;
+			*publish_update = !defGetBoolean(defel);
+		}
+		else if (strcmp(defel->defname, "publish delete") == 0)
+		{
+			if (*publish_delete_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			*publish_delete_given = true;
+			*publish_delete = defGetBoolean(defel);
+		}
+		else if (strcmp(defel->defname, "nopublish delete") == 0)
+		{
+			if (*publish_delete_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			*publish_delete_given = true;
+			*publish_delete = !defGetBoolean(defel);
+		}
+		else
+			elog(ERROR, "unrecognized option: %s", defel->defname);
+	}
+}
+
+/*
+ * Create new publication.
+ */
+ObjectAddress
+CreatePublication(CreatePublicationStmt *stmt)
+{
+	Relation	rel;
+	ObjectAddress myself;
+	Oid			puboid;
+	bool		nulls[Natts_pg_publication];
+	Datum		values[Natts_pg_publication];
+	HeapTuple	tup;
+	bool		publish_insert_given;
+	bool		publish_update_given;
+	bool		publish_delete_given;
+	bool		publish_insert;
+	bool		publish_update;
+	bool		publish_delete;
+	AclResult	aclresult;
+
+	/* must have CREATE privilege on database */
+	aclresult = pg_database_aclcheck(MyDatabaseId, GetUserId(), ACL_CREATE);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error(aclresult, ACL_KIND_DATABASE,
+					   get_database_name(MyDatabaseId));
+
+	/* FOR ALL TABLES requires superuser */
+	if (stmt->for_all_tables && !superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to create FOR ALL TABLES publication"))));
+
+	rel = heap_open(PublicationRelationId, RowExclusiveLock);
+
+	/* Check if name is used */
+	puboid = GetSysCacheOid1(PUBLICATIONNAME, CStringGetDatum(stmt->pubname));
+	if (OidIsValid(puboid))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DUPLICATE_OBJECT),
+				 errmsg("publication \"%s\" already exists",
+						stmt->pubname)));
+	}
+
+	/* Form a tuple. */
+	memset(values, 0, sizeof(values));
+	memset(nulls, false, sizeof(nulls));
+
+	values[Anum_pg_publication_pubname - 1] =
+		DirectFunctionCall1(namein, CStringGetDatum(stmt->pubname));
+	values[Anum_pg_publication_pubowner - 1] = ObjectIdGetDatum(GetUserId());
+
+	parse_publication_options(stmt->options,
+							  &publish_insert_given, &publish_insert,
+							  &publish_update_given, &publish_update,
+							  &publish_delete_given, &publish_delete);
+
+	values[Anum_pg_publication_puballtables - 1] =
+		BoolGetDatum(stmt->for_all_tables);
+	values[Anum_pg_publication_pubinsert - 1] =
+		BoolGetDatum(publish_insert);
+	values[Anum_pg_publication_pubupdate - 1] =
+		BoolGetDatum(publish_update);
+	values[Anum_pg_publication_pubdelete - 1] =
+		BoolGetDatum(publish_delete);
+
+	tup = heap_form_tuple(RelationGetDescr(rel), values, nulls);
+
+	/* Insert tuple into catalog. */
+	puboid = simple_heap_insert(rel, tup);
+	CatalogUpdateIndexes(rel, tup);
+	heap_freetuple(tup);
+
+	ObjectAddressSet(myself, PublicationRelationId, puboid);
+
+	/* Make the changes visible. */
+	CommandCounterIncrement();
+
+	if (stmt->tables)
+	{
+		List	   *rels;
+
+		Assert(list_length(stmt->tables) > 0);
+
+		rels = OpenTableList(stmt->tables);
+		PublicationAddTables(puboid, rels, true, NULL);
+		CloseTableList(rels);
+	}
+
+	heap_close(rel, RowExclusiveLock);
+
+	InvokeObjectPostCreateHook(PublicationRelationId, puboid, 0);
+
+	return myself;
+}
+
+/*
+ * Change options of a publication.
+ */
+static void
+AlterPublicationOptions(AlterPublicationStmt *stmt, Relation rel,
+					   HeapTuple tup)
+{
+	bool		nulls[Natts_pg_publication];
+	bool		replaces[Natts_pg_publication];
+	Datum		values[Natts_pg_publication];
+	bool		publish_insert_given;
+	bool		publish_update_given;
+	bool		publish_delete_given;
+	bool		publish_insert;
+	bool		publish_update;
+	bool		publish_delete;
+	ObjectAddress		obj;
+
+	parse_publication_options(stmt->options,
+							  &publish_insert_given, &publish_insert,
+							  &publish_update_given, &publish_update,
+							  &publish_delete_given, &publish_delete);
+
+	/* Everything ok, form a new tuple. */
+	memset(values, 0, sizeof(values));
+	memset(nulls, false, sizeof(nulls));
+	memset(replaces, false, sizeof(replaces));
+
+	if (publish_insert_given)
+	{
+		values[Anum_pg_publication_pubinsert - 1] =
+			BoolGetDatum(publish_insert);
+		replaces[Anum_pg_publication_pubinsert - 1] = true;
+	}
+	if (publish_update_given)
+	{
+		values[Anum_pg_publication_pubupdate - 1] =
+			BoolGetDatum(publish_update);
+		replaces[Anum_pg_publication_pubupdate - 1] = true;
+	}
+	if (publish_delete_given)
+	{
+		values[Anum_pg_publication_pubdelete - 1] =
+			BoolGetDatum(publish_delete);
+		replaces[Anum_pg_publication_pubdelete - 1] = true;
+	}
+
+	tup = heap_modify_tuple(tup, RelationGetDescr(rel), values, nulls,
+							replaces);
+
+	/* Update the catalog. */
+	simple_heap_update(rel, &tup->t_self, tup);
+	CatalogUpdateIndexes(rel, tup);
+
+	CommandCounterIncrement();
+
+	/* Invalidate the relcache. */
+	if (((Form_pg_publication) GETSTRUCT(tup))->puballtables)
+	{
+		CacheInvalidateRelcacheAll();
+	}
+	else
+	{
+		List	*relids = GetPublicationRelations(HeapTupleGetOid(tup));
+
+		/*
+		 * We don't want to send too many individual messages, at some point
+		 * it's cheaper to just reset whole relcache.
+		 */
+		if (list_length(relids) < MAX_RELCACHE_INVAL_MSGS)
+		{
+			ListCell *lc;
+
+			foreach (lc, relids)
+			{
+				Oid	relid = lfirst_oid(lc);
+
+				CacheInvalidateRelcacheByRelid(relid);
+			}
+		}
+		else
+			CacheInvalidateRelcacheAll();
+	}
+
+	ObjectAddressSet(obj, PublicationRelationId, HeapTupleGetOid(tup));
+	EventTriggerCollectSimpleCommand(obj, InvalidObjectAddress,
+									 (Node *) stmt);
+
+	InvokeObjectPostAlterHook(PublicationRelationId, HeapTupleGetOid(tup), 0);
+}
+
+/*
+ * Add or remove table to/from publication.
+ */
+static void
+AlterPublicationTables(AlterPublicationStmt *stmt, Relation rel,
+					   HeapTuple tup)
+{
+	Oid			pubid = HeapTupleGetOid(tup);
+	List	   *rels = NIL;
+	Form_pg_publication pubform = (Form_pg_publication) GETSTRUCT(tup);
+
+	/* Check that user is allowed to manipulate the publication tables. */
+	if (pubform->puballtables)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("publication \"%s\" is defined as FOR ALL TABLES",
+						NameStr(pubform->pubname)),
+				 errdetail("Tables cannot be added to or dropped from FOR ALL TABLES publications.")));
+
+	Assert(list_length(stmt->tables) > 0);
+
+	rels = OpenTableList(stmt->tables);
+
+	if (stmt->tableAction == DEFELEM_ADD)
+		PublicationAddTables(pubid, rels, false, stmt);
+	else if (stmt->tableAction == DEFELEM_DROP)
+		PublicationDropTables(pubid, rels, false);
+	else /* DEFELEM_SET */
+	{
+		List	   *oldrelids = GetPublicationRelations(pubid);
+		List	   *delrels = NIL;
+		ListCell   *oldlc;
+
+		/* Calculate which relations to drop. */
+		foreach(oldlc, oldrelids)
+		{
+			Oid			oldrelid = lfirst_oid(oldlc);
+			ListCell   *newlc;
+			bool		found = false;
+
+			foreach(newlc, rels)
+			{
+				Relation	newrel = (Relation) lfirst(newlc);
+
+				if (RelationGetRelid(newrel) == oldrelid)
+				{
+					found = true;
+					break;
+				}
+			}
+
+			if (!found)
+			{
+				Relation	oldrel = heap_open(oldrelid,
+											   ShareUpdateExclusiveLock);
+				delrels = lappend(delrels, oldrel);
+			}
+		}
+
+		/* And drop them. */
+		PublicationDropTables(pubid, delrels, true);
+
+		/*
+		 * Don't bother calculating the difference for adding, we'll catch
+		 * and skip existing ones when doing catalog update.
+		 */
+		PublicationAddTables(pubid, rels, true, stmt);
+
+		CloseTableList(delrels);
+	}
+
+	CloseTableList(rels);
+}
+
+/*
+ * Alter the existing publication.
+ *
+ * This is dispatcher function for AlterPublicationOptions and
+ * AlterPublicationTables.
+ */
+void
+AlterPublication(AlterPublicationStmt *stmt)
+{
+	Relation		rel;
+	HeapTuple		tup;
+
+	rel = heap_open(PublicationRelationId, RowExclusiveLock);
+
+	tup = SearchSysCacheCopy1(PUBLICATIONNAME,
+							  CStringGetDatum(stmt->pubname));
+
+	if (!HeapTupleIsValid(tup))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("publication \"%s\" does not exist",
+						stmt->pubname)));
+
+	/* must be owner */
+	if (!pg_publication_ownercheck(HeapTupleGetOid(tup), GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PUBLICATION,
+					   stmt->pubname);
+
+	if (stmt->options)
+		AlterPublicationOptions(stmt, rel, tup);
+	else
+		AlterPublicationTables(stmt, rel, tup);
+
+	/* Cleanup. */
+	heap_freetuple(tup);
+	heap_close(rel, RowExclusiveLock);
+}
+
+/*
+ * Drop publication by OID
+ */
+void
+RemovePublicationById(Oid pubid)
+{
+	Relation	rel;
+	HeapTuple	tup;
+
+	rel = heap_open(PublicationRelationId, RowExclusiveLock);
+
+	tup = SearchSysCache1(PUBLICATIONOID, ObjectIdGetDatum(pubid));
+
+	if (!HeapTupleIsValid(tup))
+		elog(ERROR, "cache lookup failed for publication %u", pubid);
+
+	simple_heap_delete(rel, &tup->t_self);
+
+	ReleaseSysCache(tup);
+
+	heap_close(rel, RowExclusiveLock);
+}
+
+/*
+ * Remove relation from publication by mapping OID.
+ */
+void
+RemovePublicationRelById(Oid proid)
+{
+	Relation        rel;
+	HeapTuple       tup;
+	Form_pg_publication_rel		pubrel;
+
+	rel = heap_open(PublicationRelRelationId, RowExclusiveLock);
+
+	tup = SearchSysCache1(PUBLICATIONREL, ObjectIdGetDatum(proid));
+
+	if (!HeapTupleIsValid(tup))
+		elog(ERROR, "cache lookup failed for publication table %u",
+			 proid);
+
+
+	pubrel = (Form_pg_publication_rel) GETSTRUCT(tup);
+
+	/* Invalidate relcache so that publication info is rebuilt. */
+	CacheInvalidateRelcacheByRelid(pubrel->prrelid);
+
+	simple_heap_delete(rel, &tup->t_self);
+
+	ReleaseSysCache(tup);
+
+	heap_close(rel, RowExclusiveLock);
+}
+
+/*
+ * Open relations based om provided by RangeVar list.
+ * The returned tables are locked in ShareUpdateExclusiveLock mode.
+ */
+static List *
+OpenTableList(List *tables)
+{
+	List	   *relids = NIL;
+	List	   *rels = NIL;
+	ListCell   *lc;
+
+	/*
+	 * Open, share-lock, and check all the explicitly-specified relations
+	 */
+	foreach(lc, tables)
+	{
+		RangeVar   *rv = lfirst(lc);
+		Relation	rel;
+		bool		recurse = rv->inh;
+		Oid			myrelid;
+
+		CHECK_FOR_INTERRUPTS();
+
+		rel = heap_openrv(rv, ShareUpdateExclusiveLock);
+		myrelid = RelationGetRelid(rel);
+		/*
+		 * filter out duplicates when user specifies "foo, foo"
+		 * Note that this algrithm is know to not be very effective (O(N^2))
+		 * but given that it only works on list of tables given to us by user
+		 * it's deemed acceptable.
+		 */
+		if (list_member_oid(relids, myrelid))
+		{
+			heap_close(rel, ShareUpdateExclusiveLock);
+			continue;
+		}
+		rels = lappend(rels, rel);
+		relids = lappend_oid(relids, myrelid);
+
+		if (recurse)
+		{
+			ListCell   *child;
+			List	   *children;
+
+			children = find_all_inheritors(myrelid, ShareUpdateExclusiveLock,
+										   NULL);
+
+			foreach(child, children)
+			{
+				Oid			childrelid = lfirst_oid(child);
+
+				if (list_member_oid(relids, childrelid))
+					continue;
+
+				/*
+				 * Skip duplicates if user specified both parent and child
+				 * tables.
+				 */
+				if (list_member_oid(relids, childrelid))
+				{
+					heap_close(rel, ShareUpdateExclusiveLock);
+					continue;
+				}
+
+				/* find_all_inheritors already got lock */
+				rel = heap_open(childrelid, NoLock);
+				rels = lappend(rels, rel);
+				relids = lappend_oid(relids, childrelid);
+			}
+		}
+	}
+
+	list_free(relids);
+
+	return rels;
+}
+
+/*
+ * Close all relations in the list.
+ */
+static void
+CloseTableList(List *rels)
+{
+	ListCell   *lc;
+
+	foreach(lc, rels)
+	{
+		Relation	rel = (Relation) lfirst(lc);
+
+		heap_close(rel, NoLock);
+	}
+}
+
+/*
+ * Add listed tables to the publication.
+ */
+static void
+PublicationAddTables(Oid pubid, List *rels, bool if_not_exists,
+					 AlterPublicationStmt *stmt)
+{
+	ListCell	   *lc;
+
+	Assert(!stmt || !stmt->for_all_tables);
+
+	foreach(lc, rels)
+	{
+		Relation	rel = (Relation) lfirst(lc);
+		ObjectAddress	obj;
+
+		/* Must be owner of the table or superuser. */
+		if (!pg_class_ownercheck(RelationGetRelid(rel), GetUserId()))
+			aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CLASS,
+						   RelationGetRelationName(rel));
+
+		obj = publication_add_relation(pubid, rel, if_not_exists);
+		if (stmt)
+		{
+			EventTriggerCollectSimpleCommand(obj, InvalidObjectAddress,
+											 (Node *) stmt);
+
+			InvokeObjectPostCreateHook(PublicationRelRelationId,
+									   obj.objectId, 0);
+		}
+	}
+}
+
+/*
+ * Remove listed tables from the publication.
+ */
+static void
+PublicationDropTables(Oid pubid, List *rels, bool missing_ok)
+{
+	ObjectAddress	obj;
+	ListCell	   *lc;
+	Oid				prid;
+
+	foreach(lc, rels)
+	{
+		Relation	rel = (Relation) lfirst(lc);
+		Oid			relid = RelationGetRelid(rel);
+
+		prid = GetSysCacheOid2(PUBLICATIONRELMAP, ObjectIdGetDatum(relid),
+							   ObjectIdGetDatum(pubid));
+		if (!OidIsValid(prid))
+		{
+			if (missing_ok)
+				continue;
+
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("relation \"%s\" is not part of the publication",
+							RelationGetRelationName(rel))));
+		}
+
+		ObjectAddressSet(obj, PublicationRelRelationId, prid);
+		performDeletion(&obj, DROP_CASCADE, 0);
+	}
+}
+
+/*
+ * Internal workhorse for changing a publication owner
+ */
+	static void
+AlterPublicationOwner_internal(Relation rel, HeapTuple tup, Oid newOwnerId)
+{
+	Form_pg_publication form;
+
+	form = (Form_pg_publication) GETSTRUCT(tup);
+
+	if (form->pubowner == newOwnerId)
+		return;
+
+	if (!pg_publication_ownercheck(HeapTupleGetOid(tup), GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_PUBLICATION,
+					   NameStr(form->pubname));
+
+	/* New owner must be a superuser */
+	if (!superuser_arg(newOwnerId))
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("permission denied to change owner of publication \"%s\"",
+						NameStr(form->pubname)),
+				 errhint("The owner of a publication must be a superuser.")));
+
+	form->pubowner = newOwnerId;
+	simple_heap_update(rel, &tup->t_self, tup);
+	CatalogUpdateIndexes(rel, tup);
+
+	/* Update owner dependency reference */
+	changeDependencyOnOwner(PublicationRelationId,
+							HeapTupleGetOid(tup),
+							newOwnerId);
+
+	InvokeObjectPostAlterHook(PublicationRelationId,
+							  HeapTupleGetOid(tup), 0);
+}
+
+/*
+ * Change publication owner -- by name
+ */
+ObjectAddress
+AlterPublicationOwner(const char *name, Oid newOwnerId)
+{
+	Oid                     subid;
+	HeapTuple       tup;
+	Relation        rel;
+	ObjectAddress address;
+
+	rel = heap_open(PublicationRelationId, RowExclusiveLock);
+
+	tup = SearchSysCacheCopy1(PUBLICATIONNAME, CStringGetDatum(name));
+
+	if (!HeapTupleIsValid(tup))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("publication \"%s\" does not exist", name)));
+
+	subid = HeapTupleGetOid(tup);
+
+	AlterPublicationOwner_internal(rel, tup, newOwnerId);
+
+	ObjectAddressSet(address, PublicationRelationId, subid);
+
+	heap_freetuple(tup);
+
+	heap_close(rel, RowExclusiveLock);
+
+	return address;
+}
+
+/*
+ * Change publication owner -- by OID
+ */
+void
+AlterPublicationOwner_oid(Oid subid, Oid newOwnerId)
+{
+	HeapTuple       tup;
+	Relation        rel;
+
+	rel = heap_open(PublicationRelationId, RowExclusiveLock);
+
+	tup = SearchSysCacheCopy1(PUBLICATIONOID, ObjectIdGetDatum(subid));
+
+	if (!HeapTupleIsValid(tup))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("publication with OID %u does not exist", subid)));
+
+	AlterPublicationOwner_internal(rel, tup, newOwnerId);
+
+	heap_freetuple(tup);
+
+	heap_close(rel, RowExclusiveLock);
+}

src/backend/commands/subscriptioncmds.c

@@ -0,0 +1,643 @@
+/*-------------------------------------------------------------------------
+ *
+ * subscriptioncmds.c
+ *		subscription catalog manipulation functions
+ *
+ * Copyright (c) 2015, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *		subscriptioncmds.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "miscadmin.h"
+
+#include "access/heapam.h"
+#include "access/htup_details.h"
+
+#include "catalog/indexing.h"
+#include "catalog/objectaccess.h"
+#include "catalog/objectaddress.h"
+#include "catalog/pg_type.h"
+#include "catalog/pg_subscription.h"
+
+#include "commands/defrem.h"
+#include "commands/event_trigger.h"
+#include "commands/subscriptioncmds.h"
+
+#include "replication/logicallauncher.h"
+#include "replication/origin.h"
+#include "replication/walreceiver.h"
+#include "replication/worker_internal.h"
+
+#include "storage/lmgr.h"
+
+#include "utils/builtins.h"
+#include "utils/memutils.h"
+#include "utils/syscache.h"
+
+/*
+ * Common option parsing function for CREATE and ALTER SUBSCRIPTION commands.
+ *
+ * Since not all options can be specified in both commands, this function
+ * will report an error on options if the target output pointer is NULL to
+ * accomodate that.
+ */
+static void
+parse_subscription_options(List *options, char **conninfo,
+						   List **publications, bool *enabled_given,
+						   bool *enabled, bool *create_slot, char **slot_name)
+{
+	ListCell   *lc;
+	bool		create_slot_given = false;
+
+	if (conninfo)
+		*conninfo = NULL;
+	if (publications)
+		*publications = NIL;
+	if (enabled)
+	{
+		*enabled_given = false;
+		*enabled = true;
+	}
+	if (create_slot)
+		*create_slot = true;
+	if (slot_name)
+		*slot_name = NULL;
+
+	/* Parse options */
+	foreach (lc, options)
+	{
+		DefElem    *defel = (DefElem *) lfirst(lc);
+
+		if (strcmp(defel->defname, "conninfo") == 0 && conninfo)
+		{
+			if (*conninfo)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			*conninfo = defGetString(defel);
+		}
+		else if (strcmp(defel->defname, "publication") == 0 && publications)
+		{
+			if (*publications)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			*publications = defGetStringList(defel);
+		}
+		else if (strcmp(defel->defname, "enabled") == 0 && enabled)
+		{
+			if (*enabled_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			*enabled_given = true;
+			*enabled = defGetBoolean(defel);
+		}
+		else if (strcmp(defel->defname, "disabled") == 0 && enabled)
+		{
+			if (*enabled_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			*enabled_given = true;
+			*enabled = !defGetBoolean(defel);
+		}
+		else if (strcmp(defel->defname, "create slot") == 0 && create_slot)
+		{
+			if (create_slot_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			create_slot_given = true;
+			*create_slot = defGetBoolean(defel);
+		}
+		else if (strcmp(defel->defname, "nocreate slot") == 0 && create_slot)
+		{
+			if (create_slot_given)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			create_slot_given = true;
+			*create_slot = !defGetBoolean(defel);
+		}
+		else if (strcmp(defel->defname, "slot name") == 0 && slot_name)
+		{
+			if (*slot_name)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options")));
+
+			*slot_name = defGetString(defel);
+		}
+		else
+			elog(ERROR, "unrecognized option: %s", defel->defname);
+	}
+}
+
+/*
+ * Auxiliary function to return a text array out of a list of String nodes.
+ */
+static Datum
+publicationListToArray(List *publist)
+{
+	ArrayType  *arr;
+	Datum	   *datums;
+	int			j = 0;
+	ListCell   *cell;
+	MemoryContext memcxt;
+	MemoryContext oldcxt;
+
+	/* Create memory context for temporary allocations. */
+	memcxt = AllocSetContextCreate(CurrentMemoryContext,
+								   "publicationListToArray to array",
+								   ALLOCSET_DEFAULT_MINSIZE,
+								   ALLOCSET_DEFAULT_INITSIZE,
+								   ALLOCSET_DEFAULT_MAXSIZE);
+	oldcxt = MemoryContextSwitchTo(memcxt);
+
+	datums = palloc(sizeof(text *) * list_length(publist));
+	foreach(cell, publist)
+	{
+		char	   *name = strVal(lfirst(cell));
+		ListCell   *pcell;
+
+		/* Check for duplicates. */
+		foreach(pcell, publist)
+		{
+			char	   *pname = strVal(lfirst(cell));
+
+			if (name == pname)
+				break;
+
+			if (strcmp(name, pname) == 0)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("publication name \"%s\" used more than once",
+								pname)));
+		}
+
+		datums[j++] = CStringGetTextDatum(name);
+	}
+
+	MemoryContextSwitchTo(oldcxt);
+
+	arr = construct_array(datums, list_length(publist),
+						  TEXTOID, -1, false, 'i');
+	MemoryContextDelete(memcxt);
+
+	return PointerGetDatum(arr);
+}
+
+/*
+ * Create new subscription.
+ */
+ObjectAddress
+CreateSubscription(CreateSubscriptionStmt *stmt)
+{
+	Relation	rel;
+	ObjectAddress myself;
+	Oid			subid;
+	bool		nulls[Natts_pg_subscription];
+	Datum		values[Natts_pg_subscription];
+	HeapTuple	tup;
+	bool		enabled_given;
+	bool		enabled;
+	char	   *conninfo;
+	char	   *slotname;
+	char		originname[NAMEDATALEN];
+	bool		create_slot;
+	List	   *publications;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to create subscriptions"))));
+
+	rel = heap_open(SubscriptionRelationId, RowExclusiveLock);
+
+	/* Check if name is used */
+	subid = GetSysCacheOid2(SUBSCRIPTIONNAME, MyDatabaseId,
+							CStringGetDatum(stmt->subname));
+	if (OidIsValid(subid))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DUPLICATE_OBJECT),
+				 errmsg("subscription \"%s\" already exists",
+						stmt->subname)));
+	}
+
+	/*
+	 * Parse and check options.
+	 * Connection and publication should not be specified here.
+	 */
+	parse_subscription_options(stmt->options, NULL, NULL,
+							   &enabled_given, &enabled,
+							   &create_slot, &slotname);
+	if (slotname == NULL)
+		slotname = stmt->subname;
+
+	conninfo = stmt->conninfo;
+	publications = stmt->publication;
+
+	/* Load the library providing us libpq calls. */
+	load_file("libpqwalreceiver", false);
+
+	/* Check the connection info string. */
+	walrcv_check_conninfo(conninfo);
+
+	/* Everything ok, form a new tuple. */
+	memset(values, 0, sizeof(values));
+	memset(nulls, false, sizeof(nulls));
+
+	values[Anum_pg_subscription_subdbid - 1] = ObjectIdGetDatum(MyDatabaseId);
+	values[Anum_pg_subscription_subname - 1] =
+		DirectFunctionCall1(namein, CStringGetDatum(stmt->subname));
+	values[Anum_pg_subscription_subowner - 1] = ObjectIdGetDatum(GetUserId());
+	values[Anum_pg_subscription_subenabled - 1] = BoolGetDatum(enabled);
+	values[Anum_pg_subscription_subconninfo - 1] =
+		CStringGetTextDatum(conninfo);
+	values[Anum_pg_subscription_subslotname - 1] =
+		DirectFunctionCall1(namein, CStringGetDatum(slotname));
+	values[Anum_pg_subscription_subpublications - 1] =
+		 publicationListToArray(publications);
+
+	tup = heap_form_tuple(RelationGetDescr(rel), values, nulls);
+
+	/* Insert tuple into catalog. */
+	subid = simple_heap_insert(rel, tup);
+	CatalogUpdateIndexes(rel, tup);
+	heap_freetuple(tup);
+
+	snprintf(originname, sizeof(originname), "pg_%u", subid);
+	replorigin_create(originname);
+
+	/*
+	 * If requested, create the replication slot on remote side for our
+	 * newly created subscription.
+	 */
+	if (create_slot)
+	{
+		XLogRecPtr			lsn;
+		char			   *err;
+		WalReceiverConn	   *wrconn;
+
+		/* Try to connect to the publisher. */
+		wrconn = walrcv_connect(conninfo, true, stmt->subname, &err);
+		if (!wrconn)
+			ereport(ERROR,
+					(errmsg("could not connect to the publisher: %s", err)));
+
+		walrcv_create_slot(wrconn, slotname, false, &lsn);
+		ereport(NOTICE,
+				(errmsg("created replication slot \"%s\" on publisher",
+						slotname)));
+
+		/* And we are done with the remote side. */
+		walrcv_disconnect(wrconn);
+	}
+
+	heap_close(rel, RowExclusiveLock);
+
+	ApplyLauncherWakeupAtCommit();
+
+	ObjectAddressSet(myself, SubscriptionRelationId, subid);
+
+	InvokeObjectPostCreateHook(SubscriptionRelationId, subid, 0);
+
+	return myself;
+}
+
+/*
+ * Alter the existing subscription.
+ */
+ObjectAddress
+AlterSubscription(AlterSubscriptionStmt *stmt)
+{
+	Relation	rel;
+	ObjectAddress myself;
+	bool		nulls[Natts_pg_subscription];
+	bool		replaces[Natts_pg_subscription];
+	Datum		values[Natts_pg_subscription];
+	HeapTuple	tup;
+	Oid			subid;
+	bool		enabled_given;
+	bool		enabled;
+	char	   *conninfo;
+	char	   *slot_name;
+	List	   *publications;
+
+	rel = heap_open(SubscriptionRelationId, RowExclusiveLock);
+
+	/* Fetch the existing tuple. */
+	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, MyDatabaseId,
+							  CStringGetDatum(stmt->subname));
+
+	if (!HeapTupleIsValid(tup))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("subscription \"%s\" does not exist",
+						stmt->subname)));
+
+	/* must be owner */
+	if (!pg_subscription_ownercheck(HeapTupleGetOid(tup), GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_SUBSCRIPTION,
+					   stmt->subname);
+
+	subid = HeapTupleGetOid(tup);
+
+	/* Parse options. */
+	parse_subscription_options(stmt->options, &conninfo, &publications,
+							   &enabled_given, &enabled,
+							   NULL, &slot_name);
+
+	/* Form a new tuple. */
+	memset(values, 0, sizeof(values));
+	memset(nulls, false, sizeof(nulls));
+	memset(replaces, false, sizeof(replaces));
+
+	if (enabled_given)
+	{
+		values[Anum_pg_subscription_subenabled - 1] = BoolGetDatum(enabled);
+		replaces[Anum_pg_subscription_subenabled - 1] = true;
+	}
+	if (conninfo)
+	{
+		values[Anum_pg_subscription_subconninfo - 1] =
+			CStringGetTextDatum(conninfo);
+		replaces[Anum_pg_subscription_subconninfo - 1] = true;
+	}
+	if (slot_name)
+	{
+		values[Anum_pg_subscription_subslotname - 1] =
+			DirectFunctionCall1(namein, CStringGetDatum(slot_name));
+		replaces[Anum_pg_subscription_subslotname - 1] = true;
+	}
+	if (publications != NIL)
+	{
+		values[Anum_pg_subscription_subpublications - 1] =
+			 publicationListToArray(publications);
+		replaces[Anum_pg_subscription_subpublications - 1] = true;
+	}
+
+	tup = heap_modify_tuple(tup, RelationGetDescr(rel), values, nulls,
+							replaces);
+
+	/* Update the catalog. */
+	simple_heap_update(rel, &tup->t_self, tup);
+	CatalogUpdateIndexes(rel, tup);
+
+	ObjectAddressSet(myself, SubscriptionRelationId, subid);
+
+	/* Cleanup. */
+	heap_freetuple(tup);
+	heap_close(rel, RowExclusiveLock);
+
+	InvokeObjectPostAlterHook(SubscriptionRelationId, subid, 0);
+
+	return myself;
+}
+
+/*
+ * Drop a subscription
+ */
+void
+DropSubscription(DropSubscriptionStmt *stmt)
+{
+	Relation	rel;
+	ObjectAddress myself;
+	HeapTuple	tup;
+	Oid			subid;
+	Datum		datum;
+	bool		isnull;
+	char	   *subname;
+	char	   *conninfo;
+	char	   *slotname;
+	char		originname[NAMEDATALEN];
+	char	   *err = NULL;
+	RepOriginId	originid;
+	WalReceiverConn	   *wrconn = NULL;
+	StringInfoData		cmd;
+
+	rel = heap_open(SubscriptionRelationId, RowExclusiveLock);
+
+	tup = SearchSysCache2(SUBSCRIPTIONNAME, MyDatabaseId,
+						  CStringGetDatum(stmt->subname));
+
+	if (!HeapTupleIsValid(tup))
+	{
+		heap_close(rel, NoLock);
+
+		if (!stmt->missing_ok)
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_OBJECT),
+					 errmsg("subscription \"%s\" does not exist",
+							stmt->subname)));
+		else
+			ereport(NOTICE,
+					(errmsg("subscription \"%s\" does not exist, skipping",
+							stmt->subname)));
+
+		return;
+	}
+
+	subid = HeapTupleGetOid(tup);
+
+	/* must be owner */
+	if (!pg_subscription_ownercheck(subid, GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_SUBSCRIPTION,
+					   stmt->subname);
+
+	/* DROP hook for the subscription being removed */
+	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
+
+	/*
+	 * Lock the subscription so noboby else can do anything with it
+	 * (including the replication workers).
+	 */
+	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+
+	/* Get subname */
+	datum = SysCacheGetAttr(SUBSCRIPTIONOID, tup,
+							Anum_pg_subscription_subname, &isnull);
+	Assert(!isnull);
+	subname = pstrdup(NameStr(*DatumGetName(datum)));
+
+	/* Get conninfo */
+	datum = SysCacheGetAttr(SUBSCRIPTIONOID, tup,
+							Anum_pg_subscription_subconninfo, &isnull);
+	Assert(!isnull);
+	conninfo = pstrdup(TextDatumGetCString(datum));
+
+	/* Get slotname */
+	datum = SysCacheGetAttr(SUBSCRIPTIONOID, tup,
+							Anum_pg_subscription_subslotname, &isnull);
+	Assert(!isnull);
+	slotname = pstrdup(NameStr(*DatumGetName(datum)));
+
+	ObjectAddressSet(myself, SubscriptionRelationId, subid);
+	EventTriggerSQLDropAddObject(&myself, true, true);
+
+	/* Remove the tuple from catalog. */
+	simple_heap_delete(rel, &tup->t_self);
+
+	ReleaseSysCache(tup);
+
+	/* Protect against launcher restarting the worker. */
+	LWLockAcquire(LogicalRepLauncherLock, LW_EXCLUSIVE);
+
+	/* Kill the apply worker so that the slot becomes accessible. */
+	logicalrep_worker_stop(subid);
+
+	/* Remove the origin tracking if exists. */
+	snprintf(originname, sizeof(originname), "pg_%u", subid);
+	originid = replorigin_by_name(originname, true);
+	if (originid != InvalidRepOriginId)
+		replorigin_drop(originid);
+
+	/* If the user asked to not drop the slot, we are done mow.*/
+	if (!stmt->drop_slot)
+	{
+		heap_close(rel, NoLock);
+		return;
+	}
+
+	/*
+	 * Otherwise drop the replication slot at the publisher node using
+	 * the replication connection.
+	 */
+	load_file("libpqwalreceiver", false);
+
+	initStringInfo(&cmd);
+	appendStringInfo(&cmd, "DROP_REPLICATION_SLOT \"%s\"", slotname);
+
+	wrconn = walrcv_connect(conninfo, true, subname, &err);
+	if (wrconn == NULL)
+		ereport(ERROR,
+				(errmsg("could not connect to publisher when attempting to "
+						"drop the replication slot \"%s\"", slotname),
+				 errdetail("The error was: %s", err)));
+
+	if (!walrcv_command(wrconn, cmd.data, &err))
+		ereport(ERROR,
+				(errmsg("count not drop the replication slot \"%s\" on publisher",
+						slotname),
+				 errdetail("The error was: %s", err)));
+	else
+		ereport(NOTICE,
+				(errmsg("dropped replication slot \"%s\" on publisher",
+						slotname)));
+
+	walrcv_disconnect(wrconn);
+
+	pfree(cmd.data);
+
+	heap_close(rel, NoLock);
+}
+
+/*
+ * Internal workhorse for changing a subscription owner
+ */
+static void
+AlterSubscriptionOwner_internal(Relation rel, HeapTuple tup, Oid newOwnerId)
+{
+	Form_pg_subscription form;
+
+	form = (Form_pg_subscription) GETSTRUCT(tup);
+
+	if (form->subowner == newOwnerId)
+		return;
+
+	if (!pg_subscription_ownercheck(HeapTupleGetOid(tup), GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_SUBSCRIPTION,
+					   NameStr(form->subname));
+
+	/* New owner must be a superuser */
+	if (!superuser_arg(newOwnerId))
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+		  errmsg("permission denied to change owner of subscription \"%s\"",
+				 NameStr(form->subname)),
+			 errhint("The owner of an subscription must be a superuser.")));
+
+	form->subowner = newOwnerId;
+	simple_heap_update(rel, &tup->t_self, tup);
+	CatalogUpdateIndexes(rel, tup);
+
+	/* Update owner dependency reference */
+	changeDependencyOnOwner(SubscriptionRelationId,
+							HeapTupleGetOid(tup),
+							newOwnerId);
+
+	InvokeObjectPostAlterHook(SubscriptionRelationId,
+							  HeapTupleGetOid(tup), 0);
+}
+
+/*
+ * Change subscription owner -- by name
+ */
+ObjectAddress
+AlterSubscriptionOwner(const char *name, Oid newOwnerId)
+{
+	Oid			subid;
+	HeapTuple	tup;
+	Relation	rel;
+	ObjectAddress address;
+
+	rel = heap_open(SubscriptionRelationId, RowExclusiveLock);
+
+	tup = SearchSysCacheCopy2(SUBSCRIPTIONNAME, MyDatabaseId,
+							  CStringGetDatum(name));
+
+	if (!HeapTupleIsValid(tup))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("subscription \"%s\" does not exist", name)));
+
+	subid = HeapTupleGetOid(tup);
+
+	AlterSubscriptionOwner_internal(rel, tup, newOwnerId);
+
+	ObjectAddressSet(address, SubscriptionRelationId, subid);
+
+	heap_freetuple(tup);
+
+	heap_close(rel, RowExclusiveLock);
+
+	return address;
+}
+
+/*
+ * Change subscription owner -- by OID
+ */
+void
+AlterSubscriptionOwner_oid(Oid subid, Oid newOwnerId)
+{
+	HeapTuple	tup;
+	Relation	rel;
+
+	rel = heap_open(SubscriptionRelationId, RowExclusiveLock);
+
+	tup = SearchSysCacheCopy1(SUBSCRIPTIONOID, ObjectIdGetDatum(subid));
+
+	if (!HeapTupleIsValid(tup))
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("subscription with OID %u does not exist", subid)));
+
+	AlterSubscriptionOwner_internal(rel, tup, newOwnerId);
+
+	heap_freetuple(tup);
+
+	heap_close(rel, RowExclusiveLock);
+}

src/backend/commands/tablecmds.c

@@ -12055,6 +12055,18 @@ ATPrepChangePersistence(Relation rel, bool toLogged)
 			break;
 	}
 
+	/*
+	 * Check that the table is not part any publication when changing to
+	 * UNLOGGED as UNLOGGED tables can't be published.
+	 */
+	if (!toLogged &&
+		list_length(GetRelationPublications(RelationGetRelid(rel))) > 0)
+		ereport(ERROR,
+				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				 errmsg("cannot change table \"%s\" to unlogged because it is part of a publication",
+						RelationGetRelationName(rel)),
+				 errdetail("Unlogged relations cannot be replicated.")));
+
 	/*
 	 * Check existing foreign key constraints to preserve the invariant that
 	 * permanent tables cannot reference unlogged ones.  Self-referencing