Moved other yql/essentials libs YQL-19206

init
commit_hash:7d4c435602078407bbf20dd3c32f9c90d2bbcbc0

1 files changed, 2355 insertions, 0 deletions

diff --git a/yql/essentials/parser/pg_wrapper/postgresql/src/backend/commands/subscriptioncmds.c b/yql/essentials/parser/pg_wrapper/postgresql/src/backend/commands/subscriptioncmds.c
new file mode 100644
index 00000000000..6fe111e98d3
--- /dev/null
+++ b/yql/essentials/parser/pg_wrapper/postgresql/src/backend/commands/subscriptioncmds.c
@@ -0,0 +1,2355 @@
+/*-------------------------------------------------------------------------
+ *
+ * subscriptioncmds.c
+ *		subscription catalog manipulation functions
+ *
+ * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ *		src/backend/commands/subscriptioncmds.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/htup_details.h"
+#include "access/table.h"
+#include "access/xact.h"
+#include "catalog/catalog.h"
+#include "catalog/dependency.h"
+#include "catalog/indexing.h"
+#include "catalog/namespace.h"
+#include "catalog/objectaccess.h"
+#include "catalog/objectaddress.h"
+#include "catalog/pg_authid_d.h"
+#include "catalog/pg_database_d.h"
+#include "catalog/pg_subscription.h"
+#include "catalog/pg_subscription_rel.h"
+#include "catalog/pg_type.h"
+#include "commands/dbcommands.h"
+#include "commands/defrem.h"
+#include "commands/event_trigger.h"
+#include "commands/subscriptioncmds.h"
+#include "executor/executor.h"
+#include "miscadmin.h"
+#include "nodes/makefuncs.h"
+#include "pgstat.h"
+#include "replication/logicallauncher.h"
+#include "replication/logicalworker.h"
+#include "replication/origin.h"
+#include "replication/slot.h"
+#include "replication/walreceiver.h"
+#include "replication/walsender.h"
+#include "replication/worker_internal.h"
+#include "storage/lmgr.h"
+#include "utils/acl.h"
+#include "utils/builtins.h"
+#include "utils/guc.h"
+#include "utils/lsyscache.h"
+#include "utils/memutils.h"
+#include "utils/pg_lsn.h"
+#include "utils/syscache.h"
+
+/*
+ * Options that can be specified by the user in CREATE/ALTER SUBSCRIPTION
+ * command.
+ */
+#define SUBOPT_CONNECT				0x00000001
+#define SUBOPT_ENABLED				0x00000002
+#define SUBOPT_CREATE_SLOT			0x00000004
+#define SUBOPT_SLOT_NAME			0x00000008
+#define SUBOPT_COPY_DATA			0x00000010
+#define SUBOPT_SYNCHRONOUS_COMMIT	0x00000020
+#define SUBOPT_REFRESH				0x00000040
+#define SUBOPT_BINARY				0x00000080
+#define SUBOPT_STREAMING			0x00000100
+#define SUBOPT_TWOPHASE_COMMIT		0x00000200
+#define SUBOPT_DISABLE_ON_ERR		0x00000400
+#define SUBOPT_PASSWORD_REQUIRED	0x00000800
+#define SUBOPT_RUN_AS_OWNER			0x00001000
+#define SUBOPT_LSN					0x00002000
+#define SUBOPT_ORIGIN				0x00004000
+
+/* check if the 'val' has 'bits' set */
+#define IsSet(val, bits)  (((val) & (bits)) == (bits))
+
+/*
+ * Structure to hold a bitmap representing the user-provided CREATE/ALTER
+ * SUBSCRIPTION command options and the parsed/default values of each of them.
+ */
+typedef struct SubOpts
+{
+	bits32		specified_opts;
+	char	   *slot_name;
+	char	   *synchronous_commit;
+	bool		connect;
+	bool		enabled;
+	bool		create_slot;
+	bool		copy_data;
+	bool		refresh;
+	bool		binary;
+	char		streaming;
+	bool		twophase;
+	bool		disableonerr;
+	bool		passwordrequired;
+	bool		runasowner;
+	char	   *origin;
+	XLogRecPtr	lsn;
+} SubOpts;
+
+static List *fetch_table_list(WalReceiverConn *wrconn, List *publications);
+static void check_publications_origin(WalReceiverConn *wrconn,
+									  List *publications, bool copydata,
+									  char *origin, Oid *subrel_local_oids,
+									  int subrel_count, char *subname);
+static void check_duplicates_in_publist(List *publist, Datum *datums);
+static List *merge_publications(List *oldpublist, List *newpublist, bool addpub, const char *subname);
+static void ReportSlotConnectionError(List *rstates, Oid subid, char *slotname, char *err);
+
+
+/*
+ * 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 if mutually exclusive options are specified.
+ */
+static void
+parse_subscription_options(ParseState *pstate, List *stmt_options,
+						   bits32 supported_opts, SubOpts *opts)
+{
+	ListCell   *lc;
+
+	/* Start out with cleared opts. */
+	memset(opts, 0, sizeof(SubOpts));
+
+	/* caller must expect some option */
+	Assert(supported_opts != 0);
+
+	/* If connect option is supported, these others also need to be. */
+	Assert(!IsSet(supported_opts, SUBOPT_CONNECT) ||
+		   IsSet(supported_opts, SUBOPT_ENABLED | SUBOPT_CREATE_SLOT |
+				 SUBOPT_COPY_DATA));
+
+	/* Set default values for the supported options. */
+	if (IsSet(supported_opts, SUBOPT_CONNECT))
+		opts->connect = true;
+	if (IsSet(supported_opts, SUBOPT_ENABLED))
+		opts->enabled = true;
+	if (IsSet(supported_opts, SUBOPT_CREATE_SLOT))
+		opts->create_slot = true;
+	if (IsSet(supported_opts, SUBOPT_COPY_DATA))
+		opts->copy_data = true;
+	if (IsSet(supported_opts, SUBOPT_REFRESH))
+		opts->refresh = true;
+	if (IsSet(supported_opts, SUBOPT_BINARY))
+		opts->binary = false;
+	if (IsSet(supported_opts, SUBOPT_STREAMING))
+		opts->streaming = LOGICALREP_STREAM_OFF;
+	if (IsSet(supported_opts, SUBOPT_TWOPHASE_COMMIT))
+		opts->twophase = false;
+	if (IsSet(supported_opts, SUBOPT_DISABLE_ON_ERR))
+		opts->disableonerr = false;
+	if (IsSet(supported_opts, SUBOPT_PASSWORD_REQUIRED))
+		opts->passwordrequired = true;
+	if (IsSet(supported_opts, SUBOPT_RUN_AS_OWNER))
+		opts->runasowner = false;
+	if (IsSet(supported_opts, SUBOPT_ORIGIN))
+		opts->origin = pstrdup(LOGICALREP_ORIGIN_ANY);
+
+	/* Parse options */
+	foreach(lc, stmt_options)
+	{
+		DefElem    *defel = (DefElem *) lfirst(lc);
+
+		if (IsSet(supported_opts, SUBOPT_CONNECT) &&
+			strcmp(defel->defname, "connect") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_CONNECT))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_CONNECT;
+			opts->connect = defGetBoolean(defel);
+		}
+		else if (IsSet(supported_opts, SUBOPT_ENABLED) &&
+				 strcmp(defel->defname, "enabled") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_ENABLED))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_ENABLED;
+			opts->enabled = defGetBoolean(defel);
+		}
+		else if (IsSet(supported_opts, SUBOPT_CREATE_SLOT) &&
+				 strcmp(defel->defname, "create_slot") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_CREATE_SLOT))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_CREATE_SLOT;
+			opts->create_slot = defGetBoolean(defel);
+		}
+		else if (IsSet(supported_opts, SUBOPT_SLOT_NAME) &&
+				 strcmp(defel->defname, "slot_name") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_SLOT_NAME))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_SLOT_NAME;
+			opts->slot_name = defGetString(defel);
+
+			/* Setting slot_name = NONE is treated as no slot name. */
+			if (strcmp(opts->slot_name, "none") == 0)
+				opts->slot_name = NULL;
+			else
+				ReplicationSlotValidateName(opts->slot_name, ERROR);
+		}
+		else if (IsSet(supported_opts, SUBOPT_COPY_DATA) &&
+				 strcmp(defel->defname, "copy_data") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_COPY_DATA))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_COPY_DATA;
+			opts->copy_data = defGetBoolean(defel);
+		}
+		else if (IsSet(supported_opts, SUBOPT_SYNCHRONOUS_COMMIT) &&
+				 strcmp(defel->defname, "synchronous_commit") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_SYNCHRONOUS_COMMIT))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_SYNCHRONOUS_COMMIT;
+			opts->synchronous_commit = defGetString(defel);
+
+			/* Test if the given value is valid for synchronous_commit GUC. */
+			(void) set_config_option("synchronous_commit", opts->synchronous_commit,
+									 PGC_BACKEND, PGC_S_TEST, GUC_ACTION_SET,
+									 false, 0, false);
+		}
+		else if (IsSet(supported_opts, SUBOPT_REFRESH) &&
+				 strcmp(defel->defname, "refresh") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_REFRESH))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_REFRESH;
+			opts->refresh = defGetBoolean(defel);
+		}
+		else if (IsSet(supported_opts, SUBOPT_BINARY) &&
+				 strcmp(defel->defname, "binary") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_BINARY))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_BINARY;
+			opts->binary = defGetBoolean(defel);
+		}
+		else if (IsSet(supported_opts, SUBOPT_STREAMING) &&
+				 strcmp(defel->defname, "streaming") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_STREAMING))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_STREAMING;
+			opts->streaming = defGetStreamingMode(defel);
+		}
+		else if (strcmp(defel->defname, "two_phase") == 0)
+		{
+			/*
+			 * Do not allow toggling of two_phase option. Doing so could cause
+			 * missing of transactions and lead to an inconsistent replica.
+			 * See comments atop worker.c
+			 *
+			 * Note: Unsupported twophase indicates that this call originated
+			 * from AlterSubscription.
+			 */
+			if (!IsSet(supported_opts, SUBOPT_TWOPHASE_COMMIT))
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("unrecognized subscription parameter: \"%s\"", defel->defname)));
+
+			if (IsSet(opts->specified_opts, SUBOPT_TWOPHASE_COMMIT))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_TWOPHASE_COMMIT;
+			opts->twophase = defGetBoolean(defel);
+		}
+		else if (IsSet(supported_opts, SUBOPT_DISABLE_ON_ERR) &&
+				 strcmp(defel->defname, "disable_on_error") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_DISABLE_ON_ERR))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_DISABLE_ON_ERR;
+			opts->disableonerr = defGetBoolean(defel);
+		}
+		else if (IsSet(supported_opts, SUBOPT_PASSWORD_REQUIRED) &&
+				 strcmp(defel->defname, "password_required") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_PASSWORD_REQUIRED))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_PASSWORD_REQUIRED;
+			opts->passwordrequired = defGetBoolean(defel);
+		}
+		else if (IsSet(supported_opts, SUBOPT_RUN_AS_OWNER) &&
+				 strcmp(defel->defname, "run_as_owner") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_RUN_AS_OWNER))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_RUN_AS_OWNER;
+			opts->runasowner = defGetBoolean(defel);
+		}
+		else if (IsSet(supported_opts, SUBOPT_ORIGIN) &&
+				 strcmp(defel->defname, "origin") == 0)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_ORIGIN))
+				errorConflictingDefElem(defel, pstate);
+
+			opts->specified_opts |= SUBOPT_ORIGIN;
+			pfree(opts->origin);
+
+			/*
+			 * Even though the "origin" parameter allows only "none" and "any"
+			 * values, it is implemented as a string type so that the
+			 * parameter can be extended in future versions to support
+			 * filtering using origin names specified by the user.
+			 */
+			opts->origin = defGetString(defel);
+
+			if ((pg_strcasecmp(opts->origin, LOGICALREP_ORIGIN_NONE) != 0) &&
+				(pg_strcasecmp(opts->origin, LOGICALREP_ORIGIN_ANY) != 0))
+				ereport(ERROR,
+						errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						errmsg("unrecognized origin value: \"%s\"", opts->origin));
+		}
+		else if (IsSet(supported_opts, SUBOPT_LSN) &&
+				 strcmp(defel->defname, "lsn") == 0)
+		{
+			char	   *lsn_str = defGetString(defel);
+			XLogRecPtr	lsn;
+
+			if (IsSet(opts->specified_opts, SUBOPT_LSN))
+				errorConflictingDefElem(defel, pstate);
+
+			/* Setting lsn = NONE is treated as resetting LSN */
+			if (strcmp(lsn_str, "none") == 0)
+				lsn = InvalidXLogRecPtr;
+			else
+			{
+				/* Parse the argument as LSN */
+				lsn = DatumGetLSN(DirectFunctionCall1(pg_lsn_in,
+													  CStringGetDatum(lsn_str)));
+
+				if (XLogRecPtrIsInvalid(lsn))
+					ereport(ERROR,
+							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+							 errmsg("invalid WAL location (LSN): %s", lsn_str)));
+			}
+
+			opts->specified_opts |= SUBOPT_LSN;
+			opts->lsn = lsn;
+		}
+		else
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 errmsg("unrecognized subscription parameter: \"%s\"", defel->defname)));
+	}
+
+	/*
+	 * We've been explicitly asked to not connect, that requires some
+	 * additional processing.
+	 */
+	if (!opts->connect && IsSet(supported_opts, SUBOPT_CONNECT))
+	{
+		/* Check for incompatible options from the user. */
+		if (opts->enabled &&
+			IsSet(opts->specified_opts, SUBOPT_ENABLED))
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+			/*- translator: both %s are strings of the form "option = value" */
+					 errmsg("%s and %s are mutually exclusive options",
+							"connect = false", "enabled = true")));
+
+		if (opts->create_slot &&
+			IsSet(opts->specified_opts, SUBOPT_CREATE_SLOT))
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 errmsg("%s and %s are mutually exclusive options",
+							"connect = false", "create_slot = true")));
+
+		if (opts->copy_data &&
+			IsSet(opts->specified_opts, SUBOPT_COPY_DATA))
+			ereport(ERROR,
+					(errcode(ERRCODE_SYNTAX_ERROR),
+					 errmsg("%s and %s are mutually exclusive options",
+							"connect = false", "copy_data = true")));
+
+		/* Change the defaults of other options. */
+		opts->enabled = false;
+		opts->create_slot = false;
+		opts->copy_data = false;
+	}
+
+	/*
+	 * Do additional checking for disallowed combination when slot_name = NONE
+	 * was used.
+	 */
+	if (!opts->slot_name &&
+		IsSet(opts->specified_opts, SUBOPT_SLOT_NAME))
+	{
+		if (opts->enabled)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_ENABLED))
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+				/*- translator: both %s are strings of the form "option = value" */
+						 errmsg("%s and %s are mutually exclusive options",
+								"slot_name = NONE", "enabled = true")));
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+				/*- translator: both %s are strings of the form "option = value" */
+						 errmsg("subscription with %s must also set %s",
+								"slot_name = NONE", "enabled = false")));
+		}
+
+		if (opts->create_slot)
+		{
+			if (IsSet(opts->specified_opts, SUBOPT_CREATE_SLOT))
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+				/*- translator: both %s are strings of the form "option = value" */
+						 errmsg("%s and %s are mutually exclusive options",
+								"slot_name = NONE", "create_slot = true")));
+			else
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+				/*- translator: both %s are strings of the form "option = value" */
+						 errmsg("subscription with %s must also set %s",
+								"slot_name = NONE", "create_slot = false")));
+		}
+	}
+}
+
+/*
+ * Add publication names from the list to a string.
+ */
+static void
+get_publications_str(List *publications, StringInfo dest, bool quote_literal)
+{
+	ListCell   *lc;
+	bool		first = true;
+
+	Assert(publications != NIL);
+
+	foreach(lc, publications)
+	{
+		char	   *pubname = strVal(lfirst(lc));
+
+		if (first)
+			first = false;
+		else
+			appendStringInfoString(dest, ", ");
+
+		if (quote_literal)
+			appendStringInfoString(dest, quote_literal_cstr(pubname));
+		else
+		{
+			appendStringInfoChar(dest, '"');
+			appendStringInfoString(dest, pubname);
+			appendStringInfoChar(dest, '"');
+		}
+	}
+}
+
+/*
+ * Check that the specified publications are present on the publisher.
+ */
+static void
+check_publications(WalReceiverConn *wrconn, List *publications)
+{
+	WalRcvExecResult *res;
+	StringInfo	cmd;
+	TupleTableSlot *slot;
+	List	   *publicationsCopy = NIL;
+	Oid			tableRow[1] = {TEXTOID};
+
+	cmd = makeStringInfo();
+	appendStringInfoString(cmd, "SELECT t.pubname FROM\n"
+						   " pg_catalog.pg_publication t WHERE\n"
+						   " t.pubname IN (");
+	get_publications_str(publications, cmd, true);
+	appendStringInfoChar(cmd, ')');
+
+	res = walrcv_exec(wrconn, cmd->data, 1, tableRow);
+	pfree(cmd->data);
+	pfree(cmd);
+
+	if (res->status != WALRCV_OK_TUPLES)
+		ereport(ERROR,
+				errmsg("could not receive list of publications from the publisher: %s",
+					   res->err));
+
+	publicationsCopy = list_copy(publications);
+
+	/* Process publication(s). */
+	slot = MakeSingleTupleTableSlot(res->tupledesc, &TTSOpsMinimalTuple);
+	while (tuplestore_gettupleslot(res->tuplestore, true, false, slot))
+	{
+		char	   *pubname;
+		bool		isnull;
+
+		pubname = TextDatumGetCString(slot_getattr(slot, 1, &isnull));
+		Assert(!isnull);
+
+		/* Delete the publication present in publisher from the list. */
+		publicationsCopy = list_delete(publicationsCopy, makeString(pubname));
+		ExecClearTuple(slot);
+	}
+
+	ExecDropSingleTupleTableSlot(slot);
+
+	walrcv_clear_result(res);
+
+	if (list_length(publicationsCopy))
+	{
+		/* Prepare the list of non-existent publication(s) for error message. */
+		StringInfo	pubnames = makeStringInfo();
+
+		get_publications_str(publicationsCopy, pubnames, false);
+		ereport(WARNING,
+				errcode(ERRCODE_UNDEFINED_OBJECT),
+				errmsg_plural("publication %s does not exist on the publisher",
+							  "publications %s do not exist on the publisher",
+							  list_length(publicationsCopy),
+							  pubnames->data));
+	}
+}
+
+/*
+ * Auxiliary function to build a text array out of a list of String nodes.
+ */
+static Datum
+publicationListToArray(List *publist)
+{
+	ArrayType  *arr;
+	Datum	   *datums;
+	MemoryContext memcxt;
+	MemoryContext oldcxt;
+
+	/* Create memory context for temporary allocations. */
+	memcxt = AllocSetContextCreate(CurrentMemoryContext,
+								   "publicationListToArray to array",
+								   ALLOCSET_DEFAULT_SIZES);
+	oldcxt = MemoryContextSwitchTo(memcxt);
+
+	datums = (Datum *) palloc(sizeof(Datum) * list_length(publist));
+
+	check_duplicates_in_publist(publist, datums);
+
+	MemoryContextSwitchTo(oldcxt);
+
+	arr = construct_array_builtin(datums, list_length(publist), TEXTOID);
+
+	MemoryContextDelete(memcxt);
+
+	return PointerGetDatum(arr);
+}
+
+/*
+ * Create new subscription.
+ */
+ObjectAddress
+CreateSubscription(ParseState *pstate, CreateSubscriptionStmt *stmt,
+				   bool isTopLevel)
+{
+	Relation	rel;
+	ObjectAddress myself;
+	Oid			subid;
+	bool		nulls[Natts_pg_subscription];
+	Datum		values[Natts_pg_subscription];
+	Oid			owner = GetUserId();
+	HeapTuple	tup;
+	char	   *conninfo;
+	char		originname[NAMEDATALEN];
+	List	   *publications;
+	bits32		supported_opts;
+	SubOpts		opts = {0};
+	AclResult	aclresult;
+
+	/*
+	 * Parse and check options.
+	 *
+	 * Connection and publication should not be specified here.
+	 */
+	supported_opts = (SUBOPT_CONNECT | SUBOPT_ENABLED | SUBOPT_CREATE_SLOT |
+					  SUBOPT_SLOT_NAME | SUBOPT_COPY_DATA |
+					  SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
+					  SUBOPT_STREAMING | SUBOPT_TWOPHASE_COMMIT |
+					  SUBOPT_DISABLE_ON_ERR | SUBOPT_PASSWORD_REQUIRED |
+					  SUBOPT_RUN_AS_OWNER | SUBOPT_ORIGIN);
+	parse_subscription_options(pstate, stmt->options, supported_opts, &opts);
+
+	/*
+	 * Since creating a replication slot is not transactional, rolling back
+	 * the transaction leaves the created replication slot.  So we cannot run
+	 * CREATE SUBSCRIPTION inside a transaction block if creating a
+	 * replication slot.
+	 */
+	if (opts.create_slot)
+		PreventInTransactionBlock(isTopLevel, "CREATE SUBSCRIPTION ... WITH (create_slot = true)");
+
+	/*
+	 * We don't want to allow unprivileged users to be able to trigger
+	 * attempts to access arbitrary network destinations, so require the user
+	 * to have been specifically authorized to create subscriptions.
+	 */
+	if (!has_privs_of_role(owner, ROLE_PG_CREATE_SUBSCRIPTION))
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("permission denied to create subscription"),
+				 errdetail("Only roles with privileges of the \"%s\" role may create subscriptions.",
+						   "pg_create_subscription")));
+
+	/*
+	 * Since a subscription is a database object, we also check for CREATE
+	 * permission on the database.
+	 */
+	aclresult = object_aclcheck(DatabaseRelationId, MyDatabaseId,
+								owner, ACL_CREATE);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error(aclresult, OBJECT_DATABASE,
+					   get_database_name(MyDatabaseId));
+
+	/*
+	 * Non-superusers are required to set a password for authentication, and
+	 * that password must be used by the target server, but the superuser can
+	 * exempt a subscription from this requirement.
+	 */
+	if (!opts.passwordrequired && !superuser_arg(owner))
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("password_required=false is superuser-only"),
+				 errhint("Subscriptions with the password_required option set to false may only be created or modified by the superuser.")));
+
+	/*
+	 * If built with appropriate switch, whine when regression-testing
+	 * conventions for subscription names are violated.
+	 */
+#ifdef ENFORCE_REGRESSION_TEST_NAME_RESTRICTIONS
+	if (strncmp(stmt->subname, "regress_", 8) != 0)
+		elog(WARNING, "subscriptions created by regression test cases should have names starting with \"regress_\"");
+#endif
+
+	rel = table_open(SubscriptionRelationId, RowExclusiveLock);
+
+	/* Check if name is used */
+	subid = GetSysCacheOid2(SUBSCRIPTIONNAME, Anum_pg_subscription_oid,
+							MyDatabaseId, CStringGetDatum(stmt->subname));
+	if (OidIsValid(subid))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DUPLICATE_OBJECT),
+				 errmsg("subscription \"%s\" already exists",
+						stmt->subname)));
+	}
+
+	if (!IsSet(opts.specified_opts, SUBOPT_SLOT_NAME) &&
+		opts.slot_name == NULL)
+		opts.slot_name = stmt->subname;
+
+	/* The default for synchronous_commit of subscriptions is off. */
+	if (opts.synchronous_commit == NULL)
+		opts.synchronous_commit = "off";
+
+	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, opts.passwordrequired && !superuser());
+
+	/* Everything ok, form a new tuple. */
+	memset(values, 0, sizeof(values));
+	memset(nulls, false, sizeof(nulls));
+
+	subid = GetNewOidWithIndex(rel, SubscriptionObjectIndexId,
+							   Anum_pg_subscription_oid);
+	values[Anum_pg_subscription_oid - 1] = ObjectIdGetDatum(subid);
+	values[Anum_pg_subscription_subdbid - 1] = ObjectIdGetDatum(MyDatabaseId);
+	values[Anum_pg_subscription_subskiplsn - 1] = LSNGetDatum(InvalidXLogRecPtr);
+	values[Anum_pg_subscription_subname - 1] =
+		DirectFunctionCall1(namein, CStringGetDatum(stmt->subname));
+	values[Anum_pg_subscription_subowner - 1] = ObjectIdGetDatum(owner);
+	values[Anum_pg_subscription_subenabled - 1] = BoolGetDatum(opts.enabled);
+	values[Anum_pg_subscription_subbinary - 1] = BoolGetDatum(opts.binary);
+	values[Anum_pg_subscription_substream - 1] = CharGetDatum(opts.streaming);
+	values[Anum_pg_subscription_subtwophasestate - 1] =
+		CharGetDatum(opts.twophase ?
+					 LOGICALREP_TWOPHASE_STATE_PENDING :
+					 LOGICALREP_TWOPHASE_STATE_DISABLED);
+	values[Anum_pg_subscription_subdisableonerr - 1] = BoolGetDatum(opts.disableonerr);
+	values[Anum_pg_subscription_subpasswordrequired - 1] = BoolGetDatum(opts.passwordrequired);
+	values[Anum_pg_subscription_subrunasowner - 1] = BoolGetDatum(opts.runasowner);
+	values[Anum_pg_subscription_subconninfo - 1] =
+		CStringGetTextDatum(conninfo);
+	if (opts.slot_name)
+		values[Anum_pg_subscription_subslotname - 1] =
+			DirectFunctionCall1(namein, CStringGetDatum(opts.slot_name));
+	else
+		nulls[Anum_pg_subscription_subslotname - 1] = true;
+	values[Anum_pg_subscription_subsynccommit - 1] =
+		CStringGetTextDatum(opts.synchronous_commit);
+	values[Anum_pg_subscription_subpublications - 1] =
+		publicationListToArray(publications);
+	values[Anum_pg_subscription_suborigin - 1] =
+		CStringGetTextDatum(opts.origin);
+
+	tup = heap_form_tuple(RelationGetDescr(rel), values, nulls);
+
+	/* Insert tuple into catalog. */
+	CatalogTupleInsert(rel, tup);
+	heap_freetuple(tup);
+
+	recordDependencyOnOwner(SubscriptionRelationId, subid, owner);
+
+	ReplicationOriginNameForLogicalRep(subid, InvalidOid, originname, sizeof(originname));
+	replorigin_create(originname);
+
+	/*
+	 * Connect to remote side to execute requested commands and fetch table
+	 * info.
+	 */
+	if (opts.connect)
+	{
+		char	   *err;
+		WalReceiverConn *wrconn;
+		List	   *tables;
+		ListCell   *lc;
+		char		table_state;
+		bool		must_use_password;
+
+		/* Try to connect to the publisher. */
+		must_use_password = !superuser_arg(owner) && opts.passwordrequired;
+		wrconn = walrcv_connect(conninfo, true, must_use_password,
+								stmt->subname, &err);
+		if (!wrconn)
+			ereport(ERROR,
+					(errcode(ERRCODE_CONNECTION_FAILURE),
+					 errmsg("could not connect to the publisher: %s", err)));
+
+		PG_TRY();
+		{
+			check_publications(wrconn, publications);
+			check_publications_origin(wrconn, publications, opts.copy_data,
+									  opts.origin, NULL, 0, stmt->subname);
+
+			/*
+			 * Set sync state based on if we were asked to do data copy or
+			 * not.
+			 */
+			table_state = opts.copy_data ? SUBREL_STATE_INIT : SUBREL_STATE_READY;
+
+			/*
+			 * Get the table list from publisher and build local table status
+			 * info.
+			 */
+			tables = fetch_table_list(wrconn, publications);
+			foreach(lc, tables)
+			{
+				RangeVar   *rv = (RangeVar *) lfirst(lc);
+				Oid			relid;
+
+				relid = RangeVarGetRelid(rv, AccessShareLock, false);
+
+				/* Check for supported relkind. */
+				CheckSubscriptionRelkind(get_rel_relkind(relid),
+										 rv->schemaname, rv->relname);
+
+				AddSubscriptionRelState(subid, relid, table_state,
+										InvalidXLogRecPtr);
+			}
+
+			/*
+			 * If requested, create permanent slot for the subscription. We
+			 * won't use the initial snapshot for anything, so no need to
+			 * export it.
+			 */
+			if (opts.create_slot)
+			{
+				bool		twophase_enabled = false;
+
+				Assert(opts.slot_name);
+
+				/*
+				 * Even if two_phase is set, don't create the slot with
+				 * two-phase enabled. Will enable it once all the tables are
+				 * synced and ready. This avoids race-conditions like prepared
+				 * transactions being skipped due to changes not being applied
+				 * due to checks in should_apply_changes_for_rel() when
+				 * tablesync for the corresponding tables are in progress. See
+				 * comments atop worker.c.
+				 *
+				 * Note that if tables were specified but copy_data is false
+				 * then it is safe to enable two_phase up-front because those
+				 * tables are already initially in READY state. When the
+				 * subscription has no tables, we leave the twophase state as
+				 * PENDING, to allow ALTER SUBSCRIPTION ... REFRESH
+				 * PUBLICATION to work.
+				 */
+				if (opts.twophase && !opts.copy_data && tables != NIL)
+					twophase_enabled = true;
+
+				walrcv_create_slot(wrconn, opts.slot_name, false, twophase_enabled,
+								   CRS_NOEXPORT_SNAPSHOT, NULL);
+
+				if (twophase_enabled)
+					UpdateTwoPhaseState(subid, LOGICALREP_TWOPHASE_STATE_ENABLED);
+
+				ereport(NOTICE,
+						(errmsg("created replication slot \"%s\" on publisher",
+								opts.slot_name)));
+			}
+		}
+		PG_FINALLY();
+		{
+			walrcv_disconnect(wrconn);
+		}
+		PG_END_TRY();
+	}
+	else
+		ereport(WARNING,
+				(errmsg("subscription was created, but is not connected"),
+				 errhint("To initiate replication, you must manually create the replication slot, enable the subscription, and refresh the subscription.")));
+
+	table_close(rel, RowExclusiveLock);
+
+	pgstat_create_subscription(subid);
+
+	if (opts.enabled)
+		ApplyLauncherWakeupAtCommit();
+
+	ObjectAddressSet(myself, SubscriptionRelationId, subid);
+
+	InvokeObjectPostCreateHook(SubscriptionRelationId, subid, 0);
+
+	return myself;
+}
+
+static void
+AlterSubscription_refresh(Subscription *sub, bool copy_data,
+						  List *validate_publications)
+{
+	char	   *err;
+	List	   *pubrel_names;
+	List	   *subrel_states;
+	Oid		   *subrel_local_oids;
+	Oid		   *pubrel_local_oids;
+	ListCell   *lc;
+	int			off;
+	int			remove_rel_len;
+	int			subrel_count;
+	Relation	rel = NULL;
+	typedef struct SubRemoveRels
+	{
+		Oid			relid;
+		char		state;
+	} SubRemoveRels;
+	SubRemoveRels *sub_remove_rels;
+	WalReceiverConn *wrconn;
+	bool		must_use_password;
+
+	/* Load the library providing us libpq calls. */
+	load_file("libpqwalreceiver", false);
+
+	/* Try to connect to the publisher. */
+	must_use_password = !superuser_arg(sub->owner) && sub->passwordrequired;
+	wrconn = walrcv_connect(sub->conninfo, true, must_use_password,
+							sub->name, &err);
+	if (!wrconn)
+		ereport(ERROR,
+				(errcode(ERRCODE_CONNECTION_FAILURE),
+				 errmsg("could not connect to the publisher: %s", err)));
+
+	PG_TRY();
+	{
+		if (validate_publications)
+			check_publications(wrconn, validate_publications);
+
+		/* Get the table list from publisher. */
+		pubrel_names = fetch_table_list(wrconn, sub->publications);
+
+		/* Get local table list. */
+		subrel_states = GetSubscriptionRelations(sub->oid, false);
+		subrel_count = list_length(subrel_states);
+
+		/*
+		 * Build qsorted array of local table oids for faster lookup. This can
+		 * potentially contain all tables in the database so speed of lookup
+		 * is important.
+		 */
+		subrel_local_oids = palloc(subrel_count * sizeof(Oid));
+		off = 0;
+		foreach(lc, subrel_states)
+		{
+			SubscriptionRelState *relstate = (SubscriptionRelState *) lfirst(lc);
+
+			subrel_local_oids[off++] = relstate->relid;
+		}
+		qsort(subrel_local_oids, subrel_count,
+			  sizeof(Oid), oid_cmp);
+
+		check_publications_origin(wrconn, sub->publications, copy_data,
+								  sub->origin, subrel_local_oids,
+								  subrel_count, sub->name);
+
+		/*
+		 * Rels that we want to remove from subscription and drop any slots
+		 * and origins corresponding to them.
+		 */
+		sub_remove_rels = palloc(subrel_count * sizeof(SubRemoveRels));
+
+		/*
+		 * Walk over the remote tables and try to match them to locally known
+		 * tables. If the table is not known locally create a new state for
+		 * it.
+		 *
+		 * Also builds array of local oids of remote tables for the next step.
+		 */
+		off = 0;
+		pubrel_local_oids = palloc(list_length(pubrel_names) * sizeof(Oid));
+
+		foreach(lc, pubrel_names)
+		{
+			RangeVar   *rv = (RangeVar *) lfirst(lc);
+			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,
+						 subrel_count, sizeof(Oid), oid_cmp))
+			{
+				AddSubscriptionRelState(sub->oid, relid,
+										copy_data ? SUBREL_STATE_INIT : SUBREL_STATE_READY,
+										InvalidXLogRecPtr);
+				ereport(DEBUG1,
+						(errmsg_internal("table \"%s.%s\" added to subscription \"%s\"",
+										 rv->schemaname, rv->relname, sub->name)));
+			}
+		}
+
+		/*
+		 * Next remove state for tables we should not care about anymore using
+		 * the data we collected above
+		 */
+		qsort(pubrel_local_oids, list_length(pubrel_names),
+			  sizeof(Oid), oid_cmp);
+
+		remove_rel_len = 0;
+		for (off = 0; off < subrel_count; off++)
+		{
+			Oid			relid = subrel_local_oids[off];
+
+			if (!bsearch(&relid, pubrel_local_oids,
+						 list_length(pubrel_names), sizeof(Oid), oid_cmp))
+			{
+				char		state;
+				XLogRecPtr	statelsn;
+
+				/*
+				 * Lock pg_subscription_rel with AccessExclusiveLock to
+				 * prevent any race conditions with the apply worker
+				 * re-launching workers at the same time this code is trying
+				 * to remove those tables.
+				 *
+				 * Even if new worker for this particular rel is restarted it
+				 * won't be able to make any progress as we hold exclusive
+				 * lock on pg_subscription_rel till the transaction end. It
+				 * will simply exit as there is no corresponding rel entry.
+				 *
+				 * This locking also ensures that the state of rels won't
+				 * change till we are done with this refresh operation.
+				 */
+				if (!rel)
+					rel = table_open(SubscriptionRelRelationId, AccessExclusiveLock);
+
+				/* Last known rel state. */
+				state = GetSubscriptionRelState(sub->oid, relid, &statelsn);
+
+				sub_remove_rels[remove_rel_len].relid = relid;
+				sub_remove_rels[remove_rel_len++].state = state;
+
+				RemoveSubscriptionRel(sub->oid, relid);
+
+				logicalrep_worker_stop(sub->oid, relid);
+
+				/*
+				 * For READY state, we would have already dropped the
+				 * tablesync origin.
+				 */
+				if (state != SUBREL_STATE_READY)
+				{
+					char		originname[NAMEDATALEN];
+
+					/*
+					 * Drop the tablesync's origin tracking if exists.
+					 *
+					 * It is possible that the origin is not yet created for
+					 * tablesync worker, this can happen for the states before
+					 * SUBREL_STATE_FINISHEDCOPY. The tablesync worker or
+					 * apply worker can also concurrently try to drop the
+					 * origin and by this time the origin might be already
+					 * removed. For these reasons, passing missing_ok = true.
+					 */
+					ReplicationOriginNameForLogicalRep(sub->oid, relid, originname,
+													   sizeof(originname));
+					replorigin_drop_by_name(originname, true, false);
+				}
+
+				ereport(DEBUG1,
+						(errmsg_internal("table \"%s.%s\" removed from subscription \"%s\"",
+										 get_namespace_name(get_rel_namespace(relid)),
+										 get_rel_name(relid),
+										 sub->name)));
+			}
+		}
+
+		/*
+		 * Drop the tablesync slots associated with removed tables. This has
+		 * to be at the end because otherwise if there is an error while doing
+		 * the database operations we won't be able to rollback dropped slots.
+		 */
+		for (off = 0; off < remove_rel_len; off++)
+		{
+			if (sub_remove_rels[off].state != SUBREL_STATE_READY &&
+				sub_remove_rels[off].state != SUBREL_STATE_SYNCDONE)
+			{
+				char		syncslotname[NAMEDATALEN] = {0};
+
+				/*
+				 * For READY/SYNCDONE states we know the tablesync slot has
+				 * already been dropped by the tablesync worker.
+				 *
+				 * For other states, there is no certainty, maybe the slot
+				 * does not exist yet. Also, if we fail after removing some of
+				 * the slots, next time, it will again try to drop already
+				 * dropped slots and fail. For these reasons, we allow
+				 * missing_ok = true for the drop.
+				 */
+				ReplicationSlotNameForTablesync(sub->oid, sub_remove_rels[off].relid,
+												syncslotname, sizeof(syncslotname));
+				ReplicationSlotDropAtPubNode(wrconn, syncslotname, true);
+			}
+		}
+	}
+	PG_FINALLY();
+	{
+		walrcv_disconnect(wrconn);
+	}
+	PG_END_TRY();
+
+	if (rel)
+		table_close(rel, NoLock);
+}
+
+/*
+ * Alter the existing subscription.
+ */
+ObjectAddress
+AlterSubscription(ParseState *pstate, AlterSubscriptionStmt *stmt,
+				  bool isTopLevel)
+{
+	Relation	rel;
+	ObjectAddress myself;
+	bool		nulls[Natts_pg_subscription];
+	bool		replaces[Natts_pg_subscription];
+	Datum		values[Natts_pg_subscription];
+	HeapTuple	tup;
+	Oid			subid;
+	bool		update_tuple = false;
+	Subscription *sub;
+	Form_pg_subscription form;
+	bits32		supported_opts;
+	SubOpts		opts = {0};
+
+	rel = table_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)));
+
+	form = (Form_pg_subscription) GETSTRUCT(tup);
+	subid = form->oid;
+
+	/* must be owner */
+	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+					   stmt->subname);
+
+	sub = GetSubscription(subid, false);
+
+	/*
+	 * Don't allow non-superuser modification of a subscription with
+	 * password_required=false.
+	 */
+	if (!sub->passwordrequired && !superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("password_required=false is superuser-only"),
+				 errhint("Subscriptions with the password_required option set to false may only be created or modified by the superuser.")));
+
+	/* Lock the subscription so nobody else can do anything with it. */
+	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+
+	/* Form a new tuple. */
+	memset(values, 0, sizeof(values));
+	memset(nulls, false, sizeof(nulls));
+	memset(replaces, false, sizeof(replaces));
+
+	switch (stmt->kind)
+	{
+		case ALTER_SUBSCRIPTION_OPTIONS:
+			{
+				supported_opts = (SUBOPT_SLOT_NAME |
+								  SUBOPT_SYNCHRONOUS_COMMIT | SUBOPT_BINARY |
+								  SUBOPT_STREAMING | SUBOPT_DISABLE_ON_ERR |
+								  SUBOPT_PASSWORD_REQUIRED |
+								  SUBOPT_RUN_AS_OWNER | SUBOPT_ORIGIN);
+
+				parse_subscription_options(pstate, stmt->options,
+										   supported_opts, &opts);
+
+				if (IsSet(opts.specified_opts, SUBOPT_SLOT_NAME))
+				{
+					/*
+					 * The subscription must be disabled to allow slot_name as
+					 * 'none', otherwise, the apply worker will repeatedly try
+					 * to stream the data using that slot_name which neither
+					 * exists on the publisher nor the user will be allowed to
+					 * create it.
+					 */
+					if (sub->enabled && !opts.slot_name)
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("cannot set %s for enabled subscription",
+										"slot_name = NONE")));
+
+					if (opts.slot_name)
+						values[Anum_pg_subscription_subslotname - 1] =
+							DirectFunctionCall1(namein, CStringGetDatum(opts.slot_name));
+					else
+						nulls[Anum_pg_subscription_subslotname - 1] = true;
+					replaces[Anum_pg_subscription_subslotname - 1] = true;
+				}
+
+				if (opts.synchronous_commit)
+				{
+					values[Anum_pg_subscription_subsynccommit - 1] =
+						CStringGetTextDatum(opts.synchronous_commit);
+					replaces[Anum_pg_subscription_subsynccommit - 1] = true;
+				}
+
+				if (IsSet(opts.specified_opts, SUBOPT_BINARY))
+				{
+					values[Anum_pg_subscription_subbinary - 1] =
+						BoolGetDatum(opts.binary);
+					replaces[Anum_pg_subscription_subbinary - 1] = true;
+				}
+
+				if (IsSet(opts.specified_opts, SUBOPT_STREAMING))
+				{
+					values[Anum_pg_subscription_substream - 1] =
+						CharGetDatum(opts.streaming);
+					replaces[Anum_pg_subscription_substream - 1] = true;
+				}
+
+				if (IsSet(opts.specified_opts, SUBOPT_DISABLE_ON_ERR))
+				{
+					values[Anum_pg_subscription_subdisableonerr - 1]
+						= BoolGetDatum(opts.disableonerr);
+					replaces[Anum_pg_subscription_subdisableonerr - 1]
+						= true;
+				}
+
+				if (IsSet(opts.specified_opts, SUBOPT_PASSWORD_REQUIRED))
+				{
+					/* Non-superuser may not disable password_required. */
+					if (!opts.passwordrequired && !superuser())
+						ereport(ERROR,
+								(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+								 errmsg("password_required=false is superuser-only"),
+								 errhint("Subscriptions with the password_required option set to false may only be created or modified by the superuser.")));
+
+					values[Anum_pg_subscription_subpasswordrequired - 1]
+						= BoolGetDatum(opts.passwordrequired);
+					replaces[Anum_pg_subscription_subpasswordrequired - 1]
+						= true;
+				}
+
+				if (IsSet(opts.specified_opts, SUBOPT_RUN_AS_OWNER))
+				{
+					values[Anum_pg_subscription_subrunasowner - 1] =
+						BoolGetDatum(opts.runasowner);
+					replaces[Anum_pg_subscription_subrunasowner - 1] = true;
+				}
+
+				if (IsSet(opts.specified_opts, SUBOPT_ORIGIN))
+				{
+					values[Anum_pg_subscription_suborigin - 1] =
+						CStringGetTextDatum(opts.origin);
+					replaces[Anum_pg_subscription_suborigin - 1] = true;
+				}
+
+				update_tuple = true;
+				break;
+			}
+
+		case ALTER_SUBSCRIPTION_ENABLED:
+			{
+				parse_subscription_options(pstate, stmt->options,
+										   SUBOPT_ENABLED, &opts);
+				Assert(IsSet(opts.specified_opts, SUBOPT_ENABLED));
+
+				if (!sub->slotname && opts.enabled)
+					ereport(ERROR,
+							(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+							 errmsg("cannot enable subscription that does not have a slot name")));
+
+				values[Anum_pg_subscription_subenabled - 1] =
+					BoolGetDatum(opts.enabled);
+				replaces[Anum_pg_subscription_subenabled - 1] = true;
+
+				if (opts.enabled)
+					ApplyLauncherWakeupAtCommit();
+
+				update_tuple = true;
+				break;
+			}
+
+		case ALTER_SUBSCRIPTION_CONNECTION:
+			/* Load the library providing us libpq calls. */
+			load_file("libpqwalreceiver", false);
+			/* Check the connection info string. */
+			walrcv_check_conninfo(stmt->conninfo,
+								  sub->passwordrequired && !superuser_arg(sub->owner));
+
+			values[Anum_pg_subscription_subconninfo - 1] =
+				CStringGetTextDatum(stmt->conninfo);
+			replaces[Anum_pg_subscription_subconninfo - 1] = true;
+			update_tuple = true;
+			break;
+
+		case ALTER_SUBSCRIPTION_SET_PUBLICATION:
+			{
+				supported_opts = SUBOPT_COPY_DATA | SUBOPT_REFRESH;
+				parse_subscription_options(pstate, stmt->options,
+										   supported_opts, &opts);
+
+				values[Anum_pg_subscription_subpublications - 1] =
+					publicationListToArray(stmt->publication);
+				replaces[Anum_pg_subscription_subpublications - 1] = true;
+
+				update_tuple = true;
+
+				/* Refresh if user asked us to. */
+				if (opts.refresh)
+				{
+					if (!sub->enabled)
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("ALTER SUBSCRIPTION with refresh is not allowed for disabled subscriptions"),
+								 errhint("Use ALTER SUBSCRIPTION ... SET PUBLICATION ... WITH (refresh = false).")));
+
+					/*
+					 * See ALTER_SUBSCRIPTION_REFRESH for details why this is
+					 * not allowed.
+					 */
+					if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED && opts.copy_data)
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("ALTER SUBSCRIPTION with refresh and copy_data is not allowed when two_phase is enabled"),
+								 errhint("Use ALTER SUBSCRIPTION ... SET PUBLICATION with refresh = false, or with copy_data = false, or use DROP/CREATE SUBSCRIPTION.")));
+
+					PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION with refresh");
+
+					/* Make sure refresh sees the new list of publications. */
+					sub->publications = stmt->publication;
+
+					AlterSubscription_refresh(sub, opts.copy_data,
+											  stmt->publication);
+				}
+
+				break;
+			}
+
+		case ALTER_SUBSCRIPTION_ADD_PUBLICATION:
+		case ALTER_SUBSCRIPTION_DROP_PUBLICATION:
+			{
+				List	   *publist;
+				bool		isadd = stmt->kind == ALTER_SUBSCRIPTION_ADD_PUBLICATION;
+
+				supported_opts = SUBOPT_REFRESH | SUBOPT_COPY_DATA;
+				parse_subscription_options(pstate, stmt->options,
+										   supported_opts, &opts);
+
+				publist = merge_publications(sub->publications, stmt->publication, isadd, stmt->subname);
+				values[Anum_pg_subscription_subpublications - 1] =
+					publicationListToArray(publist);
+				replaces[Anum_pg_subscription_subpublications - 1] = true;
+
+				update_tuple = true;
+
+				/* Refresh if user asked us to. */
+				if (opts.refresh)
+				{
+					/* We only need to validate user specified publications. */
+					List	   *validate_publications = (isadd) ? stmt->publication : NULL;
+
+					if (!sub->enabled)
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("ALTER SUBSCRIPTION with refresh is not allowed for disabled subscriptions"),
+						/* translator: %s is an SQL ALTER command */
+								 errhint("Use %s instead.",
+										 isadd ?
+										 "ALTER SUBSCRIPTION ... ADD PUBLICATION ... WITH (refresh = false)" :
+										 "ALTER SUBSCRIPTION ... DROP PUBLICATION ... WITH (refresh = false)")));
+
+					/*
+					 * See ALTER_SUBSCRIPTION_REFRESH for details why this is
+					 * not allowed.
+					 */
+					if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED && opts.copy_data)
+						ereport(ERROR,
+								(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+								 errmsg("ALTER SUBSCRIPTION with refresh and copy_data is not allowed when two_phase is enabled"),
+						/* translator: %s is an SQL ALTER command */
+								 errhint("Use %s with refresh = false, or with copy_data = false, or use DROP/CREATE SUBSCRIPTION.",
+										 isadd ?
+										 "ALTER SUBSCRIPTION ... ADD PUBLICATION" :
+										 "ALTER SUBSCRIPTION ... DROP PUBLICATION")));
+
+					PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION with refresh");
+
+					/* Refresh the new list of publications. */
+					sub->publications = publist;
+
+					AlterSubscription_refresh(sub, opts.copy_data,
+											  validate_publications);
+				}
+
+				break;
+			}
+
+		case ALTER_SUBSCRIPTION_REFRESH:
+			{
+				if (!sub->enabled)
+					ereport(ERROR,
+							(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+							 errmsg("ALTER SUBSCRIPTION ... REFRESH is not allowed for disabled subscriptions")));
+
+				parse_subscription_options(pstate, stmt->options,
+										   SUBOPT_COPY_DATA, &opts);
+
+				/*
+				 * The subscription option "two_phase" requires that
+				 * replication has passed the initial table synchronization
+				 * phase before the two_phase becomes properly enabled.
+				 *
+				 * But, having reached this two-phase commit "enabled" state
+				 * we must not allow any subsequent table initialization to
+				 * occur. So the ALTER SUBSCRIPTION ... REFRESH is disallowed
+				 * when the user had requested two_phase = on mode.
+				 *
+				 * The exception to this restriction is when copy_data =
+				 * false, because when copy_data is false the tablesync will
+				 * start already in READY state and will exit directly without
+				 * doing anything.
+				 *
+				 * For more details see comments atop worker.c.
+				 */
+				if (sub->twophasestate == LOGICALREP_TWOPHASE_STATE_ENABLED && opts.copy_data)
+					ereport(ERROR,
+							(errcode(ERRCODE_SYNTAX_ERROR),
+							 errmsg("ALTER SUBSCRIPTION ... REFRESH with copy_data is not allowed when two_phase is enabled"),
+							 errhint("Use ALTER SUBSCRIPTION ... REFRESH with copy_data = false, or use DROP/CREATE SUBSCRIPTION.")));
+
+				PreventInTransactionBlock(isTopLevel, "ALTER SUBSCRIPTION ... REFRESH");
+
+				AlterSubscription_refresh(sub, opts.copy_data, NULL);
+
+				break;
+			}
+
+		case ALTER_SUBSCRIPTION_SKIP:
+			{
+				parse_subscription_options(pstate, stmt->options, SUBOPT_LSN, &opts);
+
+				/* ALTER SUBSCRIPTION ... SKIP supports only LSN option */
+				Assert(IsSet(opts.specified_opts, SUBOPT_LSN));
+
+				/*
+				 * If the user sets subskiplsn, we do a sanity check to make
+				 * sure that the specified LSN is a probable value.
+				 */
+				if (!XLogRecPtrIsInvalid(opts.lsn))
+				{
+					RepOriginId originid;
+					char		originname[NAMEDATALEN];
+					XLogRecPtr	remote_lsn;
+
+					ReplicationOriginNameForLogicalRep(subid, InvalidOid,
+													   originname, sizeof(originname));
+					originid = replorigin_by_name(originname, false);
+					remote_lsn = replorigin_get_progress(originid, false);
+
+					/* Check the given LSN is at least a future LSN */
+					if (!XLogRecPtrIsInvalid(remote_lsn) && opts.lsn < remote_lsn)
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+								 errmsg("skip WAL location (LSN %X/%X) must be greater than origin LSN %X/%X",
+										LSN_FORMAT_ARGS(opts.lsn),
+										LSN_FORMAT_ARGS(remote_lsn))));
+				}
+
+				values[Anum_pg_subscription_subskiplsn - 1] = LSNGetDatum(opts.lsn);
+				replaces[Anum_pg_subscription_subskiplsn - 1] = true;
+
+				update_tuple = true;
+				break;
+			}
+
+		default:
+			elog(ERROR, "unrecognized ALTER SUBSCRIPTION kind %d",
+				 stmt->kind);
+	}
+
+	/* Update the catalog if needed. */
+	if (update_tuple)
+	{
+		tup = heap_modify_tuple(tup, RelationGetDescr(rel), values, nulls,
+								replaces);
+
+		CatalogTupleUpdate(rel, &tup->t_self, tup);
+
+		heap_freetuple(tup);
+	}
+
+	table_close(rel, RowExclusiveLock);
+
+	ObjectAddressSet(myself, SubscriptionRelationId, subid);
+
+	InvokeObjectPostAlterHook(SubscriptionRelationId, subid, 0);
+
+	/* Wake up related replication workers to handle this change quickly. */
+	LogicalRepWorkersWakeupAtCommit(subid);
+
+	return myself;
+}
+
+/*
+ * Drop a subscription
+ */
+void
+DropSubscription(DropSubscriptionStmt *stmt, bool isTopLevel)
+{
+	Relation	rel;
+	ObjectAddress myself;
+	HeapTuple	tup;
+	Oid			subid;
+	Oid			subowner;
+	Datum		datum;
+	bool		isnull;
+	char	   *subname;
+	char	   *conninfo;
+	char	   *slotname;
+	List	   *subworkers;
+	ListCell   *lc;
+	char		originname[NAMEDATALEN];
+	char	   *err = NULL;
+	WalReceiverConn *wrconn;
+	Form_pg_subscription form;
+	List	   *rstates;
+	bool		must_use_password;
+
+	/*
+	 * Lock pg_subscription with AccessExclusiveLock to ensure that the
+	 * launcher doesn't restart new worker during dropping the subscription
+	 */
+	rel = table_open(SubscriptionRelationId, AccessExclusiveLock);
+
+	tup = SearchSysCache2(SUBSCRIPTIONNAME, MyDatabaseId,
+						  CStringGetDatum(stmt->subname));
+
+	if (!HeapTupleIsValid(tup))
+	{
+		table_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;
+	}
+
+	form = (Form_pg_subscription) GETSTRUCT(tup);
+	subid = form->oid;
+	subowner = form->subowner;
+	must_use_password = !superuser_arg(subowner) && form->subpasswordrequired;
+
+	/* must be owner */
+	if (!object_ownercheck(SubscriptionRelationId, subid, GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+					   stmt->subname);
+
+	/* DROP hook for the subscription being removed */
+	InvokeObjectDropHook(SubscriptionRelationId, subid, 0);
+
+	/*
+	 * Lock the subscription so nobody else can do anything with it (including
+	 * the replication workers).
+	 */
+	LockSharedObject(SubscriptionRelationId, subid, 0, AccessExclusiveLock);
+
+	/* Get subname */
+	datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID, tup,
+								   Anum_pg_subscription_subname);
+	subname = pstrdup(NameStr(*DatumGetName(datum)));
+
+	/* Get conninfo */
+	datum = SysCacheGetAttrNotNull(SUBSCRIPTIONOID, tup,
+								   Anum_pg_subscription_subconninfo);
+	conninfo = TextDatumGetCString(datum);
+
+	/* Get slotname */
+	datum = SysCacheGetAttr(SUBSCRIPTIONOID, tup,
+							Anum_pg_subscription_subslotname, &isnull);
+	if (!isnull)
+		slotname = pstrdup(NameStr(*DatumGetName(datum)));
+	else
+		slotname = NULL;
+
+	/*
+	 * Since dropping a replication slot is not transactional, the replication
+	 * slot stays dropped even if the transaction rolls back.  So we cannot
+	 * run DROP SUBSCRIPTION inside a transaction block if dropping the
+	 * replication slot.  Also, in this case, we report a message for dropping
+	 * the subscription to the cumulative stats system.
+	 *
+	 * XXX The command name should really be something like "DROP SUBSCRIPTION
+	 * of a subscription that is associated with a replication slot", but we
+	 * don't have the proper facilities for that.
+	 */
+	if (slotname)
+		PreventInTransactionBlock(isTopLevel, "DROP SUBSCRIPTION");
+
+	ObjectAddressSet(myself, SubscriptionRelationId, subid);
+	EventTriggerSQLDropAddObject(&myself, true, true);
+
+	/* Remove the tuple from catalog. */
+	CatalogTupleDelete(rel, &tup->t_self);
+
+	ReleaseSysCache(tup);
+
+	/*
+	 * Stop all the subscription workers immediately.
+	 *
+	 * This is necessary if we are dropping the replication slot, so that the
+	 * slot becomes accessible.
+	 *
+	 * It is also necessary if the subscription is disabled and was disabled
+	 * in the same transaction.  Then the workers haven't seen the disabling
+	 * yet and will still be running, leading to hangs later when we want to
+	 * drop the replication origin.  If the subscription was disabled before
+	 * this transaction, then there shouldn't be any workers left, so this
+	 * won't make a difference.
+	 *
+	 * New workers won't be started because we hold an exclusive lock on the
+	 * subscription till the end of the transaction.
+	 */
+	LWLockAcquire(LogicalRepWorkerLock, LW_SHARED);
+	subworkers = logicalrep_workers_find(subid, false);
+	LWLockRelease(LogicalRepWorkerLock);
+	foreach(lc, subworkers)
+	{
+		LogicalRepWorker *w = (LogicalRepWorker *) lfirst(lc);
+
+		logicalrep_worker_stop(w->subid, w->relid);
+	}
+	list_free(subworkers);
+
+	/*
+	 * Remove the no-longer-useful entry in the launcher's table of apply
+	 * worker start times.
+	 *
+	 * If this transaction rolls back, the launcher might restart a failed
+	 * apply worker before wal_retrieve_retry_interval milliseconds have
+	 * elapsed, but that's pretty harmless.
+	 */
+	ApplyLauncherForgetWorkerStartTime(subid);
+
+	/*
+	 * Cleanup of tablesync replication origins.
+	 *
+	 * Any READY-state relations would already have dealt with clean-ups.
+	 *
+	 * Note that the state can't change because we have already stopped both
+	 * the apply and tablesync workers and they can't restart because of
+	 * exclusive lock on the subscription.
+	 */
+	rstates = GetSubscriptionRelations(subid, true);
+	foreach(lc, rstates)
+	{
+		SubscriptionRelState *rstate = (SubscriptionRelState *) lfirst(lc);
+		Oid			relid = rstate->relid;
+
+		/* Only cleanup resources of tablesync workers */
+		if (!OidIsValid(relid))
+			continue;
+
+		/*
+		 * Drop the tablesync's origin tracking if exists.
+		 *
+		 * It is possible that the origin is not yet created for tablesync
+		 * worker so passing missing_ok = true. This can happen for the states
+		 * before SUBREL_STATE_FINISHEDCOPY.
+		 */
+		ReplicationOriginNameForLogicalRep(subid, relid, originname,
+										   sizeof(originname));
+		replorigin_drop_by_name(originname, true, false);
+	}
+
+	/* Clean up dependencies */
+	deleteSharedDependencyRecordsFor(SubscriptionRelationId, subid, 0);
+
+	/* Remove any associated relation synchronization states. */
+	RemoveSubscriptionRel(subid, InvalidOid);
+
+	/* Remove the origin tracking if exists. */
+	ReplicationOriginNameForLogicalRep(subid, InvalidOid, originname, sizeof(originname));
+	replorigin_drop_by_name(originname, true, false);
+
+	/*
+	 * Tell the cumulative stats system that the subscription is getting
+	 * dropped.
+	 */
+	pgstat_drop_subscription(subid);
+
+	/*
+	 * If there is no slot associated with the subscription, we can finish
+	 * here.
+	 */
+	if (!slotname && rstates == NIL)
+	{
+		table_close(rel, NoLock);
+		return;
+	}
+
+	/*
+	 * Try to acquire the connection necessary for dropping slots.
+	 *
+	 * Note: If the slotname is NONE/NULL then we allow the command to finish
+	 * and users need to manually cleanup the apply and tablesync worker slots
+	 * later.
+	 *
+	 * This has to be at the end because otherwise if there is an error while
+	 * doing the database operations we won't be able to rollback dropped
+	 * slot.
+	 */
+	load_file("libpqwalreceiver", false);
+
+	wrconn = walrcv_connect(conninfo, true, must_use_password,
+							subname, &err);
+	if (wrconn == NULL)
+	{
+		if (!slotname)
+		{
+			/* be tidy */
+			list_free(rstates);
+			table_close(rel, NoLock);
+			return;
+		}
+		else
+		{
+			ReportSlotConnectionError(rstates, subid, slotname, err);
+		}
+	}
+
+	PG_TRY();
+	{
+		foreach(lc, rstates)
+		{
+			SubscriptionRelState *rstate = (SubscriptionRelState *) lfirst(lc);
+			Oid			relid = rstate->relid;
+
+			/* Only cleanup resources of tablesync workers */
+			if (!OidIsValid(relid))
+				continue;
+
+			/*
+			 * Drop the tablesync slots associated with removed tables.
+			 *
+			 * For SYNCDONE/READY states, the tablesync slot is known to have
+			 * already been dropped by the tablesync worker.
+			 *
+			 * For other states, there is no certainty, maybe the slot does
+			 * not exist yet. Also, if we fail after removing some of the
+			 * slots, next time, it will again try to drop already dropped
+			 * slots and fail. For these reasons, we allow missing_ok = true
+			 * for the drop.
+			 */
+			if (rstate->state != SUBREL_STATE_SYNCDONE)
+			{
+				char		syncslotname[NAMEDATALEN] = {0};
+
+				ReplicationSlotNameForTablesync(subid, relid, syncslotname,
+												sizeof(syncslotname));
+				ReplicationSlotDropAtPubNode(wrconn, syncslotname, true);
+			}
+		}
+
+		list_free(rstates);
+
+		/*
+		 * If there is a slot associated with the subscription, then drop the
+		 * replication slot at the publisher.
+		 */
+		if (slotname)
+			ReplicationSlotDropAtPubNode(wrconn, slotname, false);
+	}
+	PG_FINALLY();
+	{
+		walrcv_disconnect(wrconn);
+	}
+	PG_END_TRY();
+
+	table_close(rel, NoLock);
+}
+
+/*
+ * Drop the replication slot at the publisher node using the replication
+ * connection.
+ *
+ * missing_ok - if true then only issue a LOG message if the slot doesn't
+ * exist.
+ */
+void
+ReplicationSlotDropAtPubNode(WalReceiverConn *wrconn, char *slotname, bool missing_ok)
+{
+	StringInfoData cmd;
+
+	Assert(wrconn);
+
+	load_file("libpqwalreceiver", false);
+
+	initStringInfo(&cmd);
+	appendStringInfo(&cmd, "DROP_REPLICATION_SLOT %s WAIT", quote_identifier(slotname));
+
+	PG_TRY();
+	{
+		WalRcvExecResult *res;
+
+		res = walrcv_exec(wrconn, cmd.data, 0, NULL);
+
+		if (res->status == WALRCV_OK_COMMAND)
+		{
+			/* NOTICE. Success. */
+			ereport(NOTICE,
+					(errmsg("dropped replication slot \"%s\" on publisher",
+							slotname)));
+		}
+		else if (res->status == WALRCV_ERROR &&
+				 missing_ok &&
+				 res->sqlstate == ERRCODE_UNDEFINED_OBJECT)
+		{
+			/* LOG. Error, but missing_ok = true. */
+			ereport(LOG,
+					(errmsg("could not drop replication slot \"%s\" on publisher: %s",
+							slotname, res->err)));
+		}
+		else
+		{
+			/* ERROR. */
+			ereport(ERROR,
+					(errcode(ERRCODE_CONNECTION_FAILURE),
+					 errmsg("could not drop replication slot \"%s\" on publisher: %s",
+							slotname, res->err)));
+		}
+
+		walrcv_clear_result(res);
+	}
+	PG_FINALLY();
+	{
+		pfree(cmd.data);
+	}
+	PG_END_TRY();
+}
+
+/*
+ * Internal workhorse for changing a subscription owner
+ */
+static void
+AlterSubscriptionOwner_internal(Relation rel, HeapTuple tup, Oid newOwnerId)
+{
+	Form_pg_subscription form;
+	AclResult	aclresult;
+
+	form = (Form_pg_subscription) GETSTRUCT(tup);
+
+	if (form->subowner == newOwnerId)
+		return;
+
+	if (!object_ownercheck(SubscriptionRelationId, form->oid, GetUserId()))
+		aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SUBSCRIPTION,
+					   NameStr(form->subname));
+
+	/*
+	 * Don't allow non-superuser modification of a subscription with
+	 * password_required=false.
+	 */
+	if (!form->subpasswordrequired && !superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 errmsg("password_required=false is superuser-only"),
+				 errhint("Subscriptions with the password_required option set to false may only be created or modified by the superuser.")));
+
+	/* Must be able to become new owner */
+	check_can_set_role(GetUserId(), newOwnerId);
+
+	/*
+	 * current owner must have CREATE on database
+	 *
+	 * This is consistent with how ALTER SCHEMA ... OWNER TO works, but some
+	 * other object types behave differently (e.g. you can't give a table to a
+	 * user who lacks CREATE privileges on a schema).
+	 */
+	aclresult = object_aclcheck(DatabaseRelationId, MyDatabaseId,
+								GetUserId(), ACL_CREATE);
+	if (aclresult != ACLCHECK_OK)
+		aclcheck_error(aclresult, OBJECT_DATABASE,
+					   get_database_name(MyDatabaseId));
+
+	form->subowner = newOwnerId;
+	CatalogTupleUpdate(rel, &tup->t_self, tup);
+
+	/* Update owner dependency reference */
+	changeDependencyOnOwner(SubscriptionRelationId,
+							form->oid,
+							newOwnerId);
+
+	InvokeObjectPostAlterHook(SubscriptionRelationId,
+							  form->oid, 0);
+
+	/* Wake up related background processes to handle this change quickly. */
+	ApplyLauncherWakeupAtCommit();
+	LogicalRepWorkersWakeupAtCommit(form->oid);
+}
+
+/*
+ * Change subscription owner -- by name
+ */
+ObjectAddress
+AlterSubscriptionOwner(const char *name, Oid newOwnerId)
+{
+	Oid			subid;
+	HeapTuple	tup;
+	Relation	rel;
+	ObjectAddress address;
+	Form_pg_subscription form;
+
+	rel = table_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)));
+
+	form = (Form_pg_subscription) GETSTRUCT(tup);
+	subid = form->oid;
+
+	AlterSubscriptionOwner_internal(rel, tup, newOwnerId);
+
+	ObjectAddressSet(address, SubscriptionRelationId, subid);
+
+	heap_freetuple(tup);
+
+	table_close(rel, RowExclusiveLock);
+
+	return address;
+}
+
+/*
+ * Change subscription owner -- by OID
+ */
+void
+AlterSubscriptionOwner_oid(Oid subid, Oid newOwnerId)
+{
+	HeapTuple	tup;
+	Relation	rel;
+
+	rel = table_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);
+
+	table_close(rel, RowExclusiveLock);
+}
+
+/*
+ * Check and log a warning if the publisher has subscribed to the same table
+ * from some other publisher. This check is required only if "copy_data = true"
+ * and "origin = none" for CREATE SUBSCRIPTION and
+ * ALTER SUBSCRIPTION ... REFRESH statements to notify the user that data
+ * having origin might have been copied.
+ *
+ * This check need not be performed on the tables that are already added
+ * because incremental sync for those tables will happen through WAL and the
+ * origin of the data can be identified from the WAL records.
+ *
+ * subrel_local_oids contains the list of relation oids that are already
+ * present on the subscriber.
+ */
+static void
+check_publications_origin(WalReceiverConn *wrconn, List *publications,
+						  bool copydata, char *origin, Oid *subrel_local_oids,
+						  int subrel_count, char *subname)
+{
+	WalRcvExecResult *res;
+	StringInfoData cmd;
+	TupleTableSlot *slot;
+	Oid			tableRow[1] = {TEXTOID};
+	List	   *publist = NIL;
+	int			i;
+
+	if (!copydata || !origin ||
+		(pg_strcasecmp(origin, LOGICALREP_ORIGIN_NONE) != 0))
+		return;
+
+	initStringInfo(&cmd);
+	appendStringInfoString(&cmd,
+						   "SELECT DISTINCT P.pubname AS pubname\n"
+						   "FROM pg_publication P,\n"
+						   "     LATERAL pg_get_publication_tables(P.pubname) GPT\n"
+						   "     JOIN pg_subscription_rel PS ON (GPT.relid = PS.srrelid),\n"
+						   "     pg_class C JOIN pg_namespace N ON (N.oid = C.relnamespace)\n"
+						   "WHERE C.oid = GPT.relid AND P.pubname IN (");
+	get_publications_str(publications, &cmd, true);
+	appendStringInfoString(&cmd, ")\n");
+
+	/*
+	 * In case of ALTER SUBSCRIPTION ... REFRESH, subrel_local_oids contains
+	 * the list of relation oids that are already present on the subscriber.
+	 * This check should be skipped for these tables.
+	 */
+	for (i = 0; i < subrel_count; i++)
+	{
+		Oid			relid = subrel_local_oids[i];
+		char	   *schemaname = get_namespace_name(get_rel_namespace(relid));
+		char	   *tablename = get_rel_name(relid);
+
+		appendStringInfo(&cmd, "AND NOT (N.nspname = '%s' AND C.relname = '%s')\n",
+						 schemaname, tablename);
+	}
+
+	res = walrcv_exec(wrconn, cmd.data, 1, tableRow);
+	pfree(cmd.data);
+
+	if (res->status != WALRCV_OK_TUPLES)
+		ereport(ERROR,
+				(errcode(ERRCODE_CONNECTION_FAILURE),
+				 errmsg("could not receive list of replicated tables from the publisher: %s",
+						res->err)));
+
+	/* Process tables. */
+	slot = MakeSingleTupleTableSlot(res->tupledesc, &TTSOpsMinimalTuple);
+	while (tuplestore_gettupleslot(res->tuplestore, true, false, slot))
+	{
+		char	   *pubname;
+		bool		isnull;
+
+		pubname = TextDatumGetCString(slot_getattr(slot, 1, &isnull));
+		Assert(!isnull);
+
+		ExecClearTuple(slot);
+		publist = list_append_unique(publist, makeString(pubname));
+	}
+
+	/*
+	 * Log a warning if the publisher has subscribed to the same table from
+	 * some other publisher. We cannot know the origin of data during the
+	 * initial sync. Data origins can be found only from the WAL by looking at
+	 * the origin id.
+	 *
+	 * XXX: For simplicity, we don't check whether the table has any data or
+	 * not. If the table doesn't have any data then we don't need to
+	 * distinguish between data having origin and data not having origin so we
+	 * can avoid logging a warning in that case.
+	 */
+	if (publist)
+	{
+		StringInfo	pubnames = makeStringInfo();
+
+		/* Prepare the list of publication(s) for warning message. */
+		get_publications_str(publist, pubnames, false);
+		ereport(WARNING,
+				errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
+				errmsg("subscription \"%s\" requested copy_data with origin = NONE but might copy data that had a different origin",
+					   subname),
+				errdetail_plural("The subscription being created subscribes to a publication (%s) that contains tables that are written to by other subscriptions.",
+								 "The subscription being created subscribes to publications (%s) that contain tables that are written to by other subscriptions.",
+								 list_length(publist), pubnames->data),
+				errhint("Verify that initial data copied from the publisher tables did not come from other origins."));
+	}
+
+	ExecDropSingleTupleTableSlot(slot);
+
+	walrcv_clear_result(res);
+}
+
+/*
+ * Get the list of tables which belong to specified publications on the
+ * publisher connection.
+ *
+ * Note that we don't support the case where the column list is different for
+ * the same table in different publications to avoid sending unwanted column
+ * information for some of the rows. This can happen when both the column
+ * list and row filter are specified for different publications.
+ */
+static List *
+fetch_table_list(WalReceiverConn *wrconn, List *publications)
+{
+	WalRcvExecResult *res;
+	StringInfoData cmd;
+	TupleTableSlot *slot;
+	Oid			tableRow[3] = {TEXTOID, TEXTOID, InvalidOid};
+	List	   *tablelist = NIL;
+	int			server_version = walrcv_server_version(wrconn);
+	bool		check_columnlist = (server_version >= 150000);
+
+	initStringInfo(&cmd);
+
+	/* Get the list of tables from the publisher. */
+	if (server_version >= 160000)
+	{
+		StringInfoData pub_names;
+
+		tableRow[2] = INT2VECTOROID;
+		initStringInfo(&pub_names);
+		get_publications_str(publications, &pub_names, true);
+
+		/*
+		 * From version 16, we allowed passing multiple publications to the
+		 * function pg_get_publication_tables. This helped to filter out the
+		 * partition table whose ancestor is also published in this
+		 * publication array.
+		 *
+		 * Join pg_get_publication_tables with pg_publication to exclude
+		 * non-existing publications.
+		 *
+		 * Note that attrs are always stored in sorted order so we don't need
+		 * to worry if different publications have specified them in a
+		 * different order. See publication_translate_columns.
+		 */
+		appendStringInfo(&cmd, "SELECT DISTINCT n.nspname, c.relname, gpt.attrs\n"
+						 "       FROM pg_class c\n"
+						 "         JOIN pg_namespace n ON n.oid = c.relnamespace\n"
+						 "         JOIN ( SELECT (pg_get_publication_tables(VARIADIC array_agg(pubname::text))).*\n"
+						 "                FROM pg_publication\n"
+						 "                WHERE pubname IN ( %s )) AS gpt\n"
+						 "             ON gpt.relid = c.oid\n",
+						 pub_names.data);
+
+		pfree(pub_names.data);
+	}
+	else
+	{
+		tableRow[2] = NAMEARRAYOID;
+		appendStringInfoString(&cmd, "SELECT DISTINCT t.schemaname, t.tablename \n");
+
+		/* Get column lists for each relation if the publisher supports it */
+		if (check_columnlist)
+			appendStringInfoString(&cmd, ", t.attnames\n");
+
+		appendStringInfoString(&cmd, "FROM pg_catalog.pg_publication_tables t\n"
+							   " WHERE t.pubname IN (");
+		get_publications_str(publications, &cmd, true);
+		appendStringInfoChar(&cmd, ')');
+	}
+
+	res = walrcv_exec(wrconn, cmd.data, check_columnlist ? 3 : 2, tableRow);
+	pfree(cmd.data);
+
+	if (res->status != WALRCV_OK_TUPLES)
+		ereport(ERROR,
+				(errcode(ERRCODE_CONNECTION_FAILURE),
+				 errmsg("could not receive list of replicated tables from the publisher: %s",
+						res->err)));
+
+	/* Process tables. */
+	slot = MakeSingleTupleTableSlot(res->tupledesc, &TTSOpsMinimalTuple);
+	while (tuplestore_gettupleslot(res->tuplestore, true, false, slot))
+	{
+		char	   *nspname;
+		char	   *relname;
+		bool		isnull;
+		RangeVar   *rv;
+
+		nspname = TextDatumGetCString(slot_getattr(slot, 1, &isnull));
+		Assert(!isnull);
+		relname = TextDatumGetCString(slot_getattr(slot, 2, &isnull));
+		Assert(!isnull);
+
+		rv = makeRangeVar(nspname, relname, -1);
+
+		if (check_columnlist && list_member(tablelist, rv))
+			ereport(ERROR,
+					errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					errmsg("cannot use different column lists for table \"%s.%s\" in different publications",
+						   nspname, relname));
+		else
+			tablelist = lappend(tablelist, rv);
+
+		ExecClearTuple(slot);
+	}
+	ExecDropSingleTupleTableSlot(slot);
+
+	walrcv_clear_result(res);
+
+	return tablelist;
+}
+
+/*
+ * This is to report the connection failure while dropping replication slots.
+ * Here, we report the WARNING for all tablesync slots so that user can drop
+ * them manually, if required.
+ */
+static void
+ReportSlotConnectionError(List *rstates, Oid subid, char *slotname, char *err)
+{
+	ListCell   *lc;
+
+	foreach(lc, rstates)
+	{
+		SubscriptionRelState *rstate = (SubscriptionRelState *) lfirst(lc);
+		Oid			relid = rstate->relid;
+
+		/* Only cleanup resources of tablesync workers */
+		if (!OidIsValid(relid))
+			continue;
+
+		/*
+		 * Caller needs to ensure that relstate doesn't change underneath us.
+		 * See DropSubscription where we get the relstates.
+		 */
+		if (rstate->state != SUBREL_STATE_SYNCDONE)
+		{
+			char		syncslotname[NAMEDATALEN] = {0};
+
+			ReplicationSlotNameForTablesync(subid, relid, syncslotname,
+											sizeof(syncslotname));
+			elog(WARNING, "could not drop tablesync replication slot \"%s\"",
+				 syncslotname);
+		}
+	}
+
+	ereport(ERROR,
+			(errcode(ERRCODE_CONNECTION_FAILURE),
+			 errmsg("could not connect to publisher when attempting to drop replication slot \"%s\": %s",
+					slotname, err),
+	/* translator: %s is an SQL ALTER command */
+			 errhint("Use %s to disable the subscription, and then use %s to disassociate it from the slot.",
+					 "ALTER SUBSCRIPTION ... DISABLE",
+					 "ALTER SUBSCRIPTION ... SET (slot_name = NONE)")));
+}
+
+/*
+ * Check for duplicates in the given list of publications and error out if
+ * found one.  Add publications to datums as text datums, if datums is not
+ * NULL.
+ */
+static void
+check_duplicates_in_publist(List *publist, Datum *datums)
+{
+	ListCell   *cell;
+	int			j = 0;
+
+	foreach(cell, publist)
+	{
+		char	   *name = strVal(lfirst(cell));
+		ListCell   *pcell;
+
+		foreach(pcell, publist)
+		{
+			char	   *pname = strVal(lfirst(pcell));
+
+			if (pcell == cell)
+				break;
+
+			if (strcmp(name, pname) == 0)
+				ereport(ERROR,
+						(errcode(ERRCODE_DUPLICATE_OBJECT),
+						 errmsg("publication name \"%s\" used more than once",
+								pname)));
+		}
+
+		if (datums)
+			datums[j++] = CStringGetTextDatum(name);
+	}
+}
+
+/*
+ * Merge current subscription's publications and user-specified publications
+ * from ADD/DROP PUBLICATIONS.
+ *
+ * If addpub is true, we will add the list of publications into oldpublist.
+ * Otherwise, we will delete the list of publications from oldpublist.  The
+ * returned list is a copy, oldpublist itself is not changed.
+ *
+ * subname is the subscription name, for error messages.
+ */
+static List *
+merge_publications(List *oldpublist, List *newpublist, bool addpub, const char *subname)
+{
+	ListCell   *lc;
+
+	oldpublist = list_copy(oldpublist);
+
+	check_duplicates_in_publist(newpublist, NULL);
+
+	foreach(lc, newpublist)
+	{
+		char	   *name = strVal(lfirst(lc));
+		ListCell   *lc2;
+		bool		found = false;
+
+		foreach(lc2, oldpublist)
+		{
+			char	   *pubname = strVal(lfirst(lc2));
+
+			if (strcmp(name, pubname) == 0)
+			{
+				found = true;
+				if (addpub)
+					ereport(ERROR,
+							(errcode(ERRCODE_DUPLICATE_OBJECT),
+							 errmsg("publication \"%s\" is already in subscription \"%s\"",
+									name, subname)));
+				else
+					oldpublist = foreach_delete_current(oldpublist, lc2);
+
+				break;
+			}
+		}
+
+		if (addpub && !found)
+			oldpublist = lappend(oldpublist, makeString(name));
+		else if (!addpub && !found)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+					 errmsg("publication \"%s\" is not in subscription \"%s\"",
+							name, subname)));
+	}
+
+	/*
+	 * XXX Probably no strong reason for this, but for now it's to make ALTER
+	 * SUBSCRIPTION ... DROP PUBLICATION consistent with SET PUBLICATION.
+	 */
+	if (!oldpublist)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+				 errmsg("cannot drop all the publications from a subscription")));
+
+	return oldpublist;
+}
+
+/*
+ * Extract the streaming mode value from a DefElem.  This is like
+ * defGetBoolean() but also accepts the special value of "parallel".
+ */
+char
+defGetStreamingMode(DefElem *def)
+{
+	/*
+	 * If no parameter value given, assume "true" is meant.
+	 */
+	if (!def->arg)
+		return LOGICALREP_STREAM_ON;
+
+	/*
+	 * Allow 0, 1, "false", "true", "off", "on" or "parallel".
+	 */
+	switch (nodeTag(def->arg))
+	{
+		case T_Integer:
+			switch (intVal(def->arg))
+			{
+				case 0:
+					return LOGICALREP_STREAM_OFF;
+				case 1:
+					return LOGICALREP_STREAM_ON;
+				default:
+					/* otherwise, error out below */
+					break;
+			}
+			break;
+		default:
+			{
+				char	   *sval = defGetString(def);
+
+				/*
+				 * The set of strings accepted here should match up with the
+				 * grammar's opt_boolean_or_string production.
+				 */
+				if (pg_strcasecmp(sval, "false") == 0 ||
+					pg_strcasecmp(sval, "off") == 0)
+					return LOGICALREP_STREAM_OFF;
+				if (pg_strcasecmp(sval, "true") == 0 ||
+					pg_strcasecmp(sval, "on") == 0)
+					return LOGICALREP_STREAM_ON;
+				if (pg_strcasecmp(sval, "parallel") == 0)
+					return LOGICALREP_STREAM_PARALLEL;
+			}
+			break;
+	}
+
+	ereport(ERROR,
+			(errcode(ERRCODE_SYNTAX_ERROR),
+			 errmsg("%s requires a Boolean value or \"parallel\"",
+					def->defname)));
+	return LOGICALREP_STREAM_OFF;	/* keep compiler quiet */
+}